The journal publish current and comprehensive, experimental, and theoretical papers across the breadth of protistology, and cell biology of Eukaryote microorganisms including: behaviour, biochemistry, molecular biology, development, ecology, genetics, parasitology, physiology, photobiology, systematics, phylogeny, ultrastructure.
See all issues
Description
ISSN: 0065-1583
eISSN: 1689-0027
MNiSW points: 40
UIC ID: 312
DOI: 10.4467/16890027AP
Editorial team
Publisher
Uniwersytet Jagielloński w Krakowie
Affiliation
Jagiellonian University in Kraków
Publication date: 24.01.2025
Editor-in-Chief: Krzysztof Wiąckowski
John R. Dolan
Acta Protozoologica, Volume 64 / Early View, 2025
https://doi.org/10.4467/16890027AP.25.001.21142John R. Dolan
Acta Protozoologica, Volume 64 / Early View, 2025
https://doi.org/10.4467/16890027AP.25.001.21142Publication date: 05.03.2024
John R. Dolan, Eun Jin Yang, Jong-Kuk Moon
Acta Protozoologica, Volume 63, 2024, pp. 1-7
https://doi.org/10.4467/16890027AP.24.001.19426We recently documented the existence of 26 different forms of Papulifères, presumptive ciliate cysts, from plankton net tow material of the Chukchi Sea gathered in 2015, 2021, and 2022. The forms appeared to be rare, found in only 7 of the 308 samples taken in annual August surveys from 2010 to 2022. Thus, we were surprised to find them relatively common and widespread in samples gathered in August of 2023. We found 18 different Papulifére forms, 8 of which appear to be new forms, in samples from 19 of the 36 stations sampled. They were found in localities ranging from 70.5°N to 80°N. Here we report on these Papulifére forms found in 2023, providing information on morphologies and geographical distributions. With this report we have expanded the catalogue of observed Papulifére, and photographed, forms of the Chukchi Sea to a grand total of 34 of morphologically distinct forms. However, we continue to urge caution in assigning a ciliate identity to any given Papulifére form in the absence of corroborating data.
John R. Dolan, Eun Jin Yang, Jong-Kuk Moon
Acta Protozoologica, Volume 63, 2024, pp. 1-7
https://doi.org/10.4467/16890027AP.24.001.19426We recently documented the existence of 26 different forms of Papulifères, presumptive ciliate cysts, from plankton net tow material of the Chukchi Sea gathered in 2015, 2021, and 2022. The forms appeared to be rare, found in only 7 of the 308 samples taken in annual August surveys from 2010 to 2022. Thus, we were surprised to find them relatively common and widespread in samples gathered in August of 2023. We found 18 different Papulifére forms, 8 of which appear to be new forms, in samples from 19 of the 36 stations sampled. They were found in localities ranging from 70.5°N to 80°N. Here we report on these Papulifére forms found in 2023, providing information on morphologies and geographical distributions. With this report we have expanded the catalogue of observed Papulifére, and photographed, forms of the Chukchi Sea to a grand total of 34 of morphologically distinct forms. However, we continue to urge caution in assigning a ciliate identity to any given Papulifére form in the absence of corroborating data.
Publication date: 2024
Agostina Pascualat, Carolina Siebert, Gabriela C. González Garraza, Santiago J. Nenda, Gabriela C. Küppers
Acta Protozoologica, Volume 63 / Early View , 2024
https://doi.org/10.4467/16890027AP.24.002.21164Agostina Pascualat, Carolina Siebert, Gabriela C. González Garraza, Santiago J. Nenda, Gabriela C. Küppers
Acta Protozoologica, Volume 63 / Early View , 2024
https://doi.org/10.4467/16890027AP.24.002.21164Publication date: 2023
Editor-in-Chief: Krzysztof Wiąckowski
John R. Dolan, Eun Jin Yang, Jong-Kuk Moon
Acta Protozoologica, Volume 62, 2023, pp. 1-14
https://doi.org/10.4467/16890027AP.23.001.17690In the early 20th century, Alphonse Meunier described "Papulifères" as a group of enigmatic forms of unknown taxonomic affinity characterized by possessing a hyaline pimple, a "papula". In the early 1980's Papulifères were equated with cysts of tintinnid ciliates. The most conspicuous forms, the large Fusopsis, have been widely found, and are now known to resemble the cyst of a certain species of oligotrich ciliate (i.e., Cyrtostrombidium boreale). Thus today, Papulifère forms are often assumed to be cysts of oligotrich ciliates. Here we report on 26 Papulifère forms, of more or less distinct morphologies, found in the plankton of the Chukchi Sea. We found forms resembling some of those described by Meunier, and recorded here for the first time since Meunier's reports, and others that do not resemble any of Meunier's Papulifères. Here, we first review the literature on Papulifères, then we present the surprising variety of forms we found in Chukchi Sea, and for some, we provide for the first time data on morphological variability. With this report we have expanded the catalogue of observed Papulifère forms and documented variability in the dimensions of some morphotypes. However, we urge caution in assigning a ciliate species name to any given Papulifère form in the absence of corroborating data. There is a need for observational and/or sequence-based data to elucidate the identity of Papulifère forms.
Rasha H. Solimam, Alexandra Martin-Ramirez, Jose M. Rubio, Eman A. Khalifa, Bushra E. Hussein, Maha M. Wahab, Marta Lanza, Yousry A. Hawash
Acta Protozoologica, Volume 62, 2023, pp. 15-23
https://doi.org/10.4467/16890027AP.23.002.17903Malaria diagnosis continues to be one of the most important steps in the cycle of control specially in endemic countries with low parasitic load infections. Loop-mediated isothermal amplification (LAMP) and ultrasensitive PCR (Us-PCR) are two promising candidates for malaria diagnosis. A cross sectional study performed at King Faisal Hospital, Taif KSA involved patients suffering from signs and symptoms suggesting of malaria, 35 blood samples diagnosed by Nested Multiplex PCR as a reference method (13 P. falciparum, 17 P. vivax, 3 mixed P. falciparum and P. vivax) plus two negative controls were selected to be included in this study to analyse the performance of two LAMP methods (LAMP OptiGene® and LAMP WarmStart®) and two ultrasensitive PCRs (Us-PCR TARE-2 and Us-PCR Var-ATS). LAMP OptiGene® and LAMP WarmStart® performances were identical and better than the performance of Us PCR TARE 2 and Us-PCR var-ATS for P. falciparum, achieving 93.75% sensitivity, 100% specificity and 97.17% accuracy versus 87.5% sensitivity, 100% specificity and 94.29% accuracy for the Us PCR TARE 2 and 81.25% sensitivity, 94.74% specificity and 88.57% accuracy for the Us PCR var-ATS respectively. In P. vivax diagnosis LAMP OptiGene® performed excellently with 100% sensitivity, specificity, and accuracy while LAMP WarmStart® and Us-PCR Cox1 achieved 100% sensitivity, specificity 93.33% and 97.14% accuracy. The study results highlighted the benefits of using LAMP techniques for field diagnosis of malaria in different settings where the need for a more sensitive and reliable molecular tool is mandatory but at the same time removing the high cost, long turnaround time and the need of highly specialized trained technicians to perform more sophisticated molecular techniques.
Ronnilda Maria Gonçalves Araujo, Guilherme Sampaio Cabral, Fabiano Corrêa, André Ricardo Ghidini
Acta Protozoologica, Volume 62, 2023, pp. 25-37
https://doi.org/10.4467/16890027AP.23.003.18283We investigated the diversity of testate amoebae in an urban stream located within the Igarapé São Francisco Environmental Protection Area in Acre, northern Brazil, during the dry season, and evaluated the factors mediating the structure of this protist community. We collected 108 water samples for the analysis of the testate amoeba community and the limnological variables at six sampling points on the stream, between July and September 2018. We used a Redundancy Analysis (RDA) to verify the influence of environmental variables on the protist community. We recorded 76 species of testate amoebae from eight families, with most records from the families Difflugiidae, Arcellidae, Centropydae and Netzeliidae. More than half (49) of the species were recorded in Acre for the first time. The abundance of the amoebae of the family Trigonopiridae was regulated by the dissolved oxygen concentrations and the pH, while that of the Netzeliidae, Difflugiidae and Lesquereusidae was influenced by the pH, chloride concentrations, and the depth and transparency of the water. In the case of the family Arcellidae, abundance was determined by the turbidity and transparency of the water and the nitrate concentrations, while that of Centropyxis sp. was associated with the concentrations of thermotolerant coliforms. These findings indicate that, while the São Francisco stream is subject to anthropogenic impacts, it still presents adequate conditions for these organisms in some of its stretches. The abundance of these amoebae was influenced primarily by the productivity of the system, as indicated by the high protist densities recorded in the areas in which primary productivity was highest. These findings support the use of these protists in studies that investigate the most appropriate indicator organisms that respond to anthropogenic impacts and shifts in environmental quality.The results of the present study demonstrated the importance of this aquatic ecosystem for the biodiversity of the study area, and the need to further expand our knowledge on the adaptations and interactions of the aquatic communities of the Amazon region.
Shuntaro Hakozaki, Hiroki Yamanobe, Kazuma Yabuki, Taiga Shimizu, Takeru Saito, Ryota Saito, Futoshi Suizu, Tomohiro Suzuki, Yoichiro Sogame
Acta Protozoologica, Volume 62, 2023, pp. 39-44
https://doi.org/10.4467/16890027AP.23.004.18421Resting cyst formation is a crucial process of cryptobiosis in protists. In colpodid ciliates, cyst formation is accompanied by large-scale morphological changes such as changes of cell shape, resorption of cilia, and formation of a cyst wall; additionally, the cell cycle is arrested. These changes provide acquired tolerance against environmental stresses. During cyst formation, mitochondrial membrane potential is reduced and the level of the ATP synthase beta chain is suppressed, strongly indicating that metabolism has ceased. Here, however, we show that ATP levels are elevated during the initial phases of encystment implying that metabolism may not be completely suppressed. This finding suggests another aspect of resting cyst formation that is not applicable to cryptobiosis.
Junlin WU, Jiaqi Yin, Zixiang Xu, Yingli Liu, Huanyong Qin, Xin Sheng
Acta Protozoologica, Volume 62, 2023, pp. 45-56
https://doi.org/10.4467/16890027AP.23.005.18868Clément Duckert, Evelyn Greeves, Quentin Blandenier, Richard J. Payne, Edward A. D. Mitchell
Acta Protozoologica, Volume 62, 2023, pp. 57-63
https://doi.org/10.4467/16890027AP.23.006.19011John R. Dolan, Eun Jin Yang, Jong-Kuk Moon
Acta Protozoologica, Volume 62, 2023, pp. 1-14
https://doi.org/10.4467/16890027AP.23.001.17690In the early 20th century, Alphonse Meunier described "Papulifères" as a group of enigmatic forms of unknown taxonomic affinity characterized by possessing a hyaline pimple, a "papula". In the early 1980's Papulifères were equated with cysts of tintinnid ciliates. The most conspicuous forms, the large Fusopsis, have been widely found, and are now known to resemble the cyst of a certain species of oligotrich ciliate (i.e., Cyrtostrombidium boreale). Thus today, Papulifère forms are often assumed to be cysts of oligotrich ciliates. Here we report on 26 Papulifère forms, of more or less distinct morphologies, found in the plankton of the Chukchi Sea. We found forms resembling some of those described by Meunier, and recorded here for the first time since Meunier's reports, and others that do not resemble any of Meunier's Papulifères. Here, we first review the literature on Papulifères, then we present the surprising variety of forms we found in Chukchi Sea, and for some, we provide for the first time data on morphological variability. With this report we have expanded the catalogue of observed Papulifère forms and documented variability in the dimensions of some morphotypes. However, we urge caution in assigning a ciliate species name to any given Papulifère form in the absence of corroborating data. There is a need for observational and/or sequence-based data to elucidate the identity of Papulifère forms.
Rasha H. Solimam, Alexandra Martin-Ramirez, Jose M. Rubio, Eman A. Khalifa, Bushra E. Hussein, Maha M. Wahab, Marta Lanza, Yousry A. Hawash
Acta Protozoologica, Volume 62, 2023, pp. 15-23
https://doi.org/10.4467/16890027AP.23.002.17903Malaria diagnosis continues to be one of the most important steps in the cycle of control specially in endemic countries with low parasitic load infections. Loop-mediated isothermal amplification (LAMP) and ultrasensitive PCR (Us-PCR) are two promising candidates for malaria diagnosis. A cross sectional study performed at King Faisal Hospital, Taif KSA involved patients suffering from signs and symptoms suggesting of malaria, 35 blood samples diagnosed by Nested Multiplex PCR as a reference method (13 P. falciparum, 17 P. vivax, 3 mixed P. falciparum and P. vivax) plus two negative controls were selected to be included in this study to analyse the performance of two LAMP methods (LAMP OptiGene® and LAMP WarmStart®) and two ultrasensitive PCRs (Us-PCR TARE-2 and Us-PCR Var-ATS). LAMP OptiGene® and LAMP WarmStart® performances were identical and better than the performance of Us PCR TARE 2 and Us-PCR var-ATS for P. falciparum, achieving 93.75% sensitivity, 100% specificity and 97.17% accuracy versus 87.5% sensitivity, 100% specificity and 94.29% accuracy for the Us PCR TARE 2 and 81.25% sensitivity, 94.74% specificity and 88.57% accuracy for the Us PCR var-ATS respectively. In P. vivax diagnosis LAMP OptiGene® performed excellently with 100% sensitivity, specificity, and accuracy while LAMP WarmStart® and Us-PCR Cox1 achieved 100% sensitivity, specificity 93.33% and 97.14% accuracy. The study results highlighted the benefits of using LAMP techniques for field diagnosis of malaria in different settings where the need for a more sensitive and reliable molecular tool is mandatory but at the same time removing the high cost, long turnaround time and the need of highly specialized trained technicians to perform more sophisticated molecular techniques.
Ronnilda Maria Gonçalves Araujo, Guilherme Sampaio Cabral, Fabiano Corrêa, André Ricardo Ghidini
Acta Protozoologica, Volume 62, 2023, pp. 25-37
https://doi.org/10.4467/16890027AP.23.003.18283We investigated the diversity of testate amoebae in an urban stream located within the Igarapé São Francisco Environmental Protection Area in Acre, northern Brazil, during the dry season, and evaluated the factors mediating the structure of this protist community. We collected 108 water samples for the analysis of the testate amoeba community and the limnological variables at six sampling points on the stream, between July and September 2018. We used a Redundancy Analysis (RDA) to verify the influence of environmental variables on the protist community. We recorded 76 species of testate amoebae from eight families, with most records from the families Difflugiidae, Arcellidae, Centropydae and Netzeliidae. More than half (49) of the species were recorded in Acre for the first time. The abundance of the amoebae of the family Trigonopiridae was regulated by the dissolved oxygen concentrations and the pH, while that of the Netzeliidae, Difflugiidae and Lesquereusidae was influenced by the pH, chloride concentrations, and the depth and transparency of the water. In the case of the family Arcellidae, abundance was determined by the turbidity and transparency of the water and the nitrate concentrations, while that of Centropyxis sp. was associated with the concentrations of thermotolerant coliforms. These findings indicate that, while the São Francisco stream is subject to anthropogenic impacts, it still presents adequate conditions for these organisms in some of its stretches. The abundance of these amoebae was influenced primarily by the productivity of the system, as indicated by the high protist densities recorded in the areas in which primary productivity was highest. These findings support the use of these protists in studies that investigate the most appropriate indicator organisms that respond to anthropogenic impacts and shifts in environmental quality.The results of the present study demonstrated the importance of this aquatic ecosystem for the biodiversity of the study area, and the need to further expand our knowledge on the adaptations and interactions of the aquatic communities of the Amazon region.
Shuntaro Hakozaki, Hiroki Yamanobe, Kazuma Yabuki, Taiga Shimizu, Takeru Saito, Ryota Saito, Futoshi Suizu, Tomohiro Suzuki, Yoichiro Sogame
Acta Protozoologica, Volume 62, 2023, pp. 39-44
https://doi.org/10.4467/16890027AP.23.004.18421Resting cyst formation is a crucial process of cryptobiosis in protists. In colpodid ciliates, cyst formation is accompanied by large-scale morphological changes such as changes of cell shape, resorption of cilia, and formation of a cyst wall; additionally, the cell cycle is arrested. These changes provide acquired tolerance against environmental stresses. During cyst formation, mitochondrial membrane potential is reduced and the level of the ATP synthase beta chain is suppressed, strongly indicating that metabolism has ceased. Here, however, we show that ATP levels are elevated during the initial phases of encystment implying that metabolism may not be completely suppressed. This finding suggests another aspect of resting cyst formation that is not applicable to cryptobiosis.
Junlin WU, Jiaqi Yin, Zixiang Xu, Yingli Liu, Huanyong Qin, Xin Sheng
Acta Protozoologica, Volume 62, 2023, pp. 45-56
https://doi.org/10.4467/16890027AP.23.005.18868Clément Duckert, Evelyn Greeves, Quentin Blandenier, Richard J. Payne, Edward A. D. Mitchell
Acta Protozoologica, Volume 62, 2023, pp. 57-63
https://doi.org/10.4467/16890027AP.23.006.19011Publication date: 2022
Editor-in-Chief: Krzysztof Wiąckowski
Yasmin de Góes Cohn Freitas, Beatriz Rodrigues D’Oliveira Ramos, Viviane Bernardes dos Santos Miranda, Yemna Gomes da Silva, Gabriela Silva Sampaio, Letícia da Silva Nascimento, Christina Wyss Castelo Branco
Acta Protozoologica, Volume 61, 2022, pp. 1-21
https://doi.org/10.4467/16890027AP.22.001.15671Testate amoebae (TA) are unicellular protozoans enclosed in a test capable of indicating a wide variety of environmental conditions. Among others, characteristics such as short life cycle, great sensitivity and worldwide distribution makes them adequate bioindicators. As a complement to physical and chemical measurements, biomonitoring can be a cheaper and fastest way of environmental monitoring. This research sought to evaluate the extent of TA use in biomonitoring and the responses given by them to environmental features. The research was conducted in Scielo, Science Direct, Online Library, Google Scholar and Capes Journal Portal and yielded 211 papers. TA bioindication is able to provide information on metal, trace element and atmospheric pollution, and to point out different trophic states, pH, and evidence on characteristics of hydrology. Further, TA can be used in paleoenvironmental reconstruction as they reflect climate, volcanic and even sea level change phenomena. Sometimes, together with other organisms in environmental analysis, they have shown to be an important complement to biomonitoring. Additionally, a functional traits approach has been recently included as a promising tool. Methodological adjustments that have been conducted throughout the years are allowing TA use to be more reliable and precise. This review provides insight on the many possible functions of TA in bioindication studies, highlighting their wide use as bioindicators.
Eman S. El-Wakil, Eman Ali Mohamed, Eman Ahmed El-Wakil, Tarek S. AbouShousha, Neimat Mousa Amer
Acta Protozoologica, Volume 61, 2022, pp. 23-34
https://doi.org/10.4467/16890027AP.22.002.16205Cryptosporidium parvum, an Apicomplexan parasite, is an important cause of diarrheal disease, especially in immunodeficient hosts. Nevertheless, there is no entirely successful therapeutic agent against cryptosporidiosis to date. Hence, this study aims to test the potential prophylactic and therapeutic effect of Camellia sinensis (green tea extract) in dexamethasone immunosuppressed mice versus the nowadays used drug, Nitazoxanide (NTZ). Parasitological and molecular methods were used to characterize Cryptosporidium oocysts before infection. Fifty bred female Swiss Albino mice were divided into 5 groups; group I (GI)(GTP): immunosuppressed and prophylactically treated with green tea extract for 5 days prior to infection, group II (GII)(GTT): immunosuppressed, infected with Cryptosporidium parvum and treated with green tea extract, group III (GIII)(NT): immunosuppressed, infected and treated with NTZ, group IV (GIV)(PC): immunosuppressed and infected (Positive control), group V (GV)(NC): immunosuppressed and non-infected (Negative control). Furthermore, parasitological examination for oocysts in the stool, and histopathological examination for the small intestine and liver specimens were performed for the study groups. Cryptosporidium oocysts used for induction of infection proved to be Cryptosporidium parvum genotype 2. Moreover, a significant oocyst reduction in fecal samples correlated with an improvement of histopathological changes in the small intestinal and liver tissues in GI(GTP), GII (GTT) and GIII(NT) groups. Besides, the GII(GTT) group showed the best improvement in parasitological and histopathological parameters among the test groups. This study revealed that Camellia sinensis (green tea extract) has potential activity against cryptosporidiosis and could serve as a promising prophylactic and therapeutic anti-cryptosporidial agent.
Ľubomír Rajter, Borong Lu, Erika Rassoshanska, Micah Dunthorn
Acta Protozoologica, Volume 61, 2022, pp. 35-46
https://doi.org/10.4467/16890027AP.22.005.16236Ciliates have a long history of being central in evolutionary and ecological studies on eukaryotic microorganisms. Although thousands of species have been discovered, their total diversity still remains unknown. Here, we will discuss two unsolved problems that hinder the further exploration of ciliate diversity at the species level, and potential solutions to these problems are proposed. First, ciliate morphospecies are difficult to identify because the different silver stains are not scalable (they do not represent high-throughput methods) and basic supplies are lacking (e.g., protargol); a solution may be the development of fluorescent staining techniques. Second, ciliate phylogenetic species are difficult to identify because of extensive paralogy in nuclear-protein-coding genes; a solution may be to concentrate on sequencing mitochondrial genomes. These two approaches could be integrated into a high-throughput fluorescent-single-cell sorting and mitochondrial genomes sequencing process that would enable the observation and better understanding of ciliate species on a massive scale.
O. Roger Anderson
Acta Protozoologica, Volume 61, 2022, pp. 47-75
https://doi.org/10.4467/16890027AP.22.003.16206The application of molecular phylogenetics to research on protists has substantially transformed our understanding of their evolution and systematics. More recently, advances in molecular technology, including high throughput sequencing, has opened new avenues for genomic analyses that elucidate major aspects of protistan biology across all levels of biological organization from cellular to ecosystems. This is a review of recent advances (particularly in the last two decades) of transcriptomic research on heterotrophic and autotrophic protists within three major topics: (i) Physiology and metabolism, (ii) Development and life cycles, and (iii) Environmental and ecological studies. Emphasis is placed on selection of representative research that highlights findings across diverse taxonomic groups within each of the three topics. Examples are drawn from parasitic as well as free-living taxa to provide a broad overview of some of the research strategies, and major findings, that have emerged from application of transcriptomics and related techniques in advancing our understanding of protistan biology.
O. Roger Anderson
Acta Protozoologica, Volume 61, 2022, pp. 77-83
https://doi.org/10.4467/16890027AP.22.007.16990Marshes bordering rivers and estuaries are productive ecosystems that interact dynamically with the adjacent water mass. This is a multi-year study (2019–2022) of seasonal changes in the density of naked amoebae in monthly samples from the surface water of the Hudson estuary near Piermont, N. Y. with relationships to key environmental variables (surface water temperature, salinity, Secchi depth representing turbidity, and enterococcus bacterial counts). During the colder months (November to March), when decayed leaves and litter from the deciduous marsh grass produced organic matter in the sediment surface, the mean abundance of active amoebae ± standard error of the mean (SEM) was higher (3.07 ± 0.99 × 10⁴/ L, N = 7). In warmer months (May to September) the abundance of amoebae was lower (1.35 ± 0.29 × 10⁴ / L, N = 10). A multivariate linear regression analysis was performed relating amoeba abundance to four major water mass variables, resulting in the following statistically significant equation (p = 0.03): AD = 0.121 × T + 0.301 × L – 0.047 × S + 0.359 × C, where: AD = active amoebae density (× 10 /L), T = temperature ( C), L = tide level (m), S = Secchi disc depth (cm) and C = bacterial enterococcus concentration (number/ml). In general, given the increasing evidence of the potential importance of amoeboid protists in aquatic ecosystems, further research is warranted on their role in food webs and the carbon biogeochemical cycle within heterotrophic estuarine and coastal waters.
Esra Elif Aydin, Won Je Lee
Acta Protozoologica, Volume 61, 2022, pp. 85-98
https://doi.org/10.4467/16890027AP.22.008.17111This study was carried out in two hypersaline lakes (Acı and Meke Lakes) in Turkey to understand the diversity and geographic distribution of free-living heterotrophic flagellates. Heterotrophic flagellates of hypersaline environments have not previously been studied in Turkey. We found seventeen morphospecies of heterotrophic flagellates with one unidentified protist. The observed species belong to Craspedida, Heterolobosea, Apusomonadida, Neobodonida, Bicosoecida and Protista incertae sedis. Of the 17 species, ten species were new records for Turkey. All of the morphospecies described here except one unidentified protist were previously reported elsewhere and appear to be cosmopolitan.
Yasmin de Góes Cohn Freitas, Beatriz Rodrigues D’Oliveira Ramos, Viviane Bernardes dos Santos Miranda, Yemna Gomes da Silva, Gabriela Silva Sampaio, Letícia da Silva Nascimento, Christina Wyss Castelo Branco
Acta Protozoologica, Volume 61, 2022, pp. 1-21
https://doi.org/10.4467/16890027AP.22.001.15671Testate amoebae (TA) are unicellular protozoans enclosed in a test capable of indicating a wide variety of environmental conditions. Among others, characteristics such as short life cycle, great sensitivity and worldwide distribution makes them adequate bioindicators. As a complement to physical and chemical measurements, biomonitoring can be a cheaper and fastest way of environmental monitoring. This research sought to evaluate the extent of TA use in biomonitoring and the responses given by them to environmental features. The research was conducted in Scielo, Science Direct, Online Library, Google Scholar and Capes Journal Portal and yielded 211 papers. TA bioindication is able to provide information on metal, trace element and atmospheric pollution, and to point out different trophic states, pH, and evidence on characteristics of hydrology. Further, TA can be used in paleoenvironmental reconstruction as they reflect climate, volcanic and even sea level change phenomena. Sometimes, together with other organisms in environmental analysis, they have shown to be an important complement to biomonitoring. Additionally, a functional traits approach has been recently included as a promising tool. Methodological adjustments that have been conducted throughout the years are allowing TA use to be more reliable and precise. This review provides insight on the many possible functions of TA in bioindication studies, highlighting their wide use as bioindicators.
Eman S. El-Wakil, Eman Ali Mohamed, Eman Ahmed El-Wakil, Tarek S. AbouShousha, Neimat Mousa Amer
Acta Protozoologica, Volume 61, 2022, pp. 23-34
https://doi.org/10.4467/16890027AP.22.002.16205Cryptosporidium parvum, an Apicomplexan parasite, is an important cause of diarrheal disease, especially in immunodeficient hosts. Nevertheless, there is no entirely successful therapeutic agent against cryptosporidiosis to date. Hence, this study aims to test the potential prophylactic and therapeutic effect of Camellia sinensis (green tea extract) in dexamethasone immunosuppressed mice versus the nowadays used drug, Nitazoxanide (NTZ). Parasitological and molecular methods were used to characterize Cryptosporidium oocysts before infection. Fifty bred female Swiss Albino mice were divided into 5 groups; group I (GI)(GTP): immunosuppressed and prophylactically treated with green tea extract for 5 days prior to infection, group II (GII)(GTT): immunosuppressed, infected with Cryptosporidium parvum and treated with green tea extract, group III (GIII)(NT): immunosuppressed, infected and treated with NTZ, group IV (GIV)(PC): immunosuppressed and infected (Positive control), group V (GV)(NC): immunosuppressed and non-infected (Negative control). Furthermore, parasitological examination for oocysts in the stool, and histopathological examination for the small intestine and liver specimens were performed for the study groups. Cryptosporidium oocysts used for induction of infection proved to be Cryptosporidium parvum genotype 2. Moreover, a significant oocyst reduction in fecal samples correlated with an improvement of histopathological changes in the small intestinal and liver tissues in GI(GTP), GII (GTT) and GIII(NT) groups. Besides, the GII(GTT) group showed the best improvement in parasitological and histopathological parameters among the test groups. This study revealed that Camellia sinensis (green tea extract) has potential activity against cryptosporidiosis and could serve as a promising prophylactic and therapeutic anti-cryptosporidial agent.
Ľubomír Rajter, Borong Lu, Erika Rassoshanska, Micah Dunthorn
Acta Protozoologica, Volume 61, 2022, pp. 35-46
https://doi.org/10.4467/16890027AP.22.005.16236Ciliates have a long history of being central in evolutionary and ecological studies on eukaryotic microorganisms. Although thousands of species have been discovered, their total diversity still remains unknown. Here, we will discuss two unsolved problems that hinder the further exploration of ciliate diversity at the species level, and potential solutions to these problems are proposed. First, ciliate morphospecies are difficult to identify because the different silver stains are not scalable (they do not represent high-throughput methods) and basic supplies are lacking (e.g., protargol); a solution may be the development of fluorescent staining techniques. Second, ciliate phylogenetic species are difficult to identify because of extensive paralogy in nuclear-protein-coding genes; a solution may be to concentrate on sequencing mitochondrial genomes. These two approaches could be integrated into a high-throughput fluorescent-single-cell sorting and mitochondrial genomes sequencing process that would enable the observation and better understanding of ciliate species on a massive scale.
O. Roger Anderson
Acta Protozoologica, Volume 61, 2022, pp. 47-75
https://doi.org/10.4467/16890027AP.22.003.16206The application of molecular phylogenetics to research on protists has substantially transformed our understanding of their evolution and systematics. More recently, advances in molecular technology, including high throughput sequencing, has opened new avenues for genomic analyses that elucidate major aspects of protistan biology across all levels of biological organization from cellular to ecosystems. This is a review of recent advances (particularly in the last two decades) of transcriptomic research on heterotrophic and autotrophic protists within three major topics: (i) Physiology and metabolism, (ii) Development and life cycles, and (iii) Environmental and ecological studies. Emphasis is placed on selection of representative research that highlights findings across diverse taxonomic groups within each of the three topics. Examples are drawn from parasitic as well as free-living taxa to provide a broad overview of some of the research strategies, and major findings, that have emerged from application of transcriptomics and related techniques in advancing our understanding of protistan biology.
O. Roger Anderson
Acta Protozoologica, Volume 61, 2022, pp. 77-83
https://doi.org/10.4467/16890027AP.22.007.16990Marshes bordering rivers and estuaries are productive ecosystems that interact dynamically with the adjacent water mass. This is a multi-year study (2019–2022) of seasonal changes in the density of naked amoebae in monthly samples from the surface water of the Hudson estuary near Piermont, N. Y. with relationships to key environmental variables (surface water temperature, salinity, Secchi depth representing turbidity, and enterococcus bacterial counts). During the colder months (November to March), when decayed leaves and litter from the deciduous marsh grass produced organic matter in the sediment surface, the mean abundance of active amoebae ± standard error of the mean (SEM) was higher (3.07 ± 0.99 × 10⁴/ L, N = 7). In warmer months (May to September) the abundance of amoebae was lower (1.35 ± 0.29 × 10⁴ / L, N = 10). A multivariate linear regression analysis was performed relating amoeba abundance to four major water mass variables, resulting in the following statistically significant equation (p = 0.03): AD = 0.121 × T + 0.301 × L – 0.047 × S + 0.359 × C, where: AD = active amoebae density (× 10 /L), T = temperature ( C), L = tide level (m), S = Secchi disc depth (cm) and C = bacterial enterococcus concentration (number/ml). In general, given the increasing evidence of the potential importance of amoeboid protists in aquatic ecosystems, further research is warranted on their role in food webs and the carbon biogeochemical cycle within heterotrophic estuarine and coastal waters.
Esra Elif Aydin, Won Je Lee
Acta Protozoologica, Volume 61, 2022, pp. 85-98
https://doi.org/10.4467/16890027AP.22.008.17111This study was carried out in two hypersaline lakes (Acı and Meke Lakes) in Turkey to understand the diversity and geographic distribution of free-living heterotrophic flagellates. Heterotrophic flagellates of hypersaline environments have not previously been studied in Turkey. We found seventeen morphospecies of heterotrophic flagellates with one unidentified protist. The observed species belong to Craspedida, Heterolobosea, Apusomonadida, Neobodonida, Bicosoecida and Protista incertae sedis. Of the 17 species, ten species were new records for Turkey. All of the morphospecies described here except one unidentified protist were previously reported elsewhere and appear to be cosmopolitan.
Publication date: 2021
Editor-in-Chief: Krzysztof Wiąckowski
John R. Dolan, Jong-Kuk Moon, Eun Jin Yang
Acta Protozoologica, Volume 60, 2021, pp. 1-11
https://doi.org/10.4467/16890027AP.21.001.14061Here we summarize the results from 10 cruises in the Chukchi Sea, in August, each year from 2011 to 2020. Samples for the qualitative analysis of the microzooplankton were obtained from stations located across the Chukchi Sea using a 20μm plankton net. Conditions encountered, in terms of sea ice coverage and chlorophyll concentrations, varied widely from year to year without any obvious relationship with the composition of the microzooplankton assemblage. Examining a total of 242 samples gathered, we found a total of 44 tintinnid species (morphologically distinct forms). Plotting cumulative number of tintinnid species encountered vs cumulative number of samplings gave a typical species accumulation curve showing no sign of saturation suggesting that continued sampling in the Chukchi Sea will likely yield increases in the tintinnid species catalogue. The tintinnid species found ranged widely in lorica opening diameters (LOD) from about 11 μm to 80 μm in diameter. However, the median size of the LOD of the tintinnid assemblages varied little from year to year ranging only from about 30 μm to 40 μm. Most of the forms encountered were found in samples from only 1 or 2 cruises. Very few forms were found every year throughout the 10 years of sampling. These were 5 species of tintinnids (Acanthostomella norvegica, Leprotintinnus pellucidus, Pytchocylis obtusa, Salpingella acuminata, Salpingella faurei) and the nasselarian radiolarian Amphimelissa setosa. Examples of the morphological variability observed among individuals of Acanthostomella norvegica and Pytchocylis obtusa within single samples are shown with some individuals easily confused with forms described as other species are shown. To our knowledge, our data are the most extensive data set on Chukchi Sea microplankton. We provide all of the data recorded, which may serve as a baseline from which to assess changes projected in Arctic Sea systems, in a supplementary data file.
Piotr Solarczyk
Acta Protozoologica, Volume 60, 2021, pp. 13-20
https://doi.org/10.4467/16890027AP.21.002.14062Cyclospora is an intracellular, gastrointestinal parasite found in birds and mammals worldwide. Limited accessibility of the protozoan for experimental use, scarcity, genome heterogeneity of the isolates and narrow panel of molecular markers hamper zoonotic investigations. One of the significant limitation in zoonotic studies is the lack of precise molecular tools that would be useful in linking animal vectors as a source of human infection. Strong and convincing evidence of zoonotic features will be achieved through proper typing of Cyclospora spp. taxonomic units (e.g. species or genotypes) in animal reservoirs. The most promising method that can be employ for zoonotic surveys is next-generation sequencing.
Kaio Cesar Simiano Tavares, Maria Gabriela Casagrande Dambrós, André Saraiva Leão Antunes, Pietro Martin Danziato, Patricia Hermes Stoco, Aline Daiane Schlindwein, Renato Simões Moreira, Luiz Claudio Miletti
Acta Protozoologica, Volume 60, 2021, pp. 21-29
https://doi.org/10.4467/16890027AP.21.003.14063Selenoproteins have been described in all three domains of life and their function has been mainly associated with oxidative stress defense. Canonical elements required for selenoprotein production have been identified in members of the kinetoplastid group supporting the existence of a complete selenocysteine synthesis pathway in these organisms. Currently, nothing is known regarding the selenocysteine pathway in Trypanosoma evansi. In this study, we identified the expression of the elements selB, selC, selD, PSTK and selTRYP at the mRNA level in T. evansi. All translated proteins (selD, PSTK, selTRYP and selB) have the domains predicted and higher identity with Trypanosoma brucei. gambiense. The selenophosphate synthetase protein was localized in the cytoplasm. Our results support the existence of an active selenocysteine pathway in T. evansi.
Tuğba Sağlam, Mustafa Yaman, Ömer Ertürk
Acta Protozoologica, Volume 60, 2021, pp. 31-36
https://doi.org/10.4467/16890027AP.21.004.14064The Indian meal moth, Plodia interpunctella (Lepidoptera: Pyralidae) is one of the most important stored product pests. Fumigation plays a significant role in the management of insect pests in stored-products. However, the use of fumigants is problematic because of their effects on the environment and high costs. Entomopathogenic organisms are environmentally friendly control agents and suppress pest populations under natural conditions. In this study, distribution and occurrence of a microsporidian pathogen, Vairimorpha plodiae (Opisthokonta: Microspora) in the populations of P. interpunctella from 12 localities representing Turkey between 2019 and 2020 are presented for the first time by confirming its effectiveness on natural populations. The presence of the microsporidian pathogen was found in 11 of 12 (91.7%) populations. In total, 863 of 3,044 samples were infected by the pathogen. Infection mean was 28.4% for all populations. Our results showed that V. plodiae infection reached to a considerably high prevalence (88.77%) in P. interpunctella populations and varied from 5.1 to 88.7% between the populations. In addition, microsporidia infections have been identified throughout Turkey. We found that V. plodiae can infect all life stages of P. interpunctella. Totally, 623 (28.5%) of 2187 larvae, 14 (37.8%) of 37 pupae, 226 (27%) of 820 adults were found to be infected by the pathogen. There were considerable differences between the dead and living larvae. The microsporidian infection was found in 26 (11.6%) of 225 living larvae, whereas it was found in 595 (30.5%) of 1,952 dead larvae. These results confirm that the microsporidia pathogen has a high spreading potential in P. interpunctella populations and can be a natural biological suppression factor on pest populations.
Abida Akbar , Abdul Hameed, Abdulaziz S. Alouffi, Mashal M. Almutairi, Tania Tanveer, Abdul Matin
Acta Protozoologica, Volume 60, 2021, pp. 37-45
https://doi.org/10.4467/16890027AP.21.005.15379Naegleria belongs to the free-living amoeba family and is well-known as a human pathogen. It is recognized as etiological agent of primary amoebic meningoencephalitis involving central nervous system which always leads to death. To date, there is not a single report demonstrating Naegleria isolation and identification from environmental sources of Rawlakot, Azad Jammu and Kashmir Pakistan, and thus the aim of this study. Naegleria was isolated on non-nutrient agar plates seeded with heat killed E. coli and confirmed by morphological properties of the both stages of cyst or trophozoites. Furthermore, PCR was conducted along with direct sequencing of the PCR product for molecular identification. PCR and sequencing data verified the amplification of Naegleria sp. (07) and Vahlkampfia sp. (01) from both water and soil samples. Interestingly two species were successfully isolated and cultured on both 30 and 45°C. To the best of our knowledge this is the first report demonstrating the Naegleria isolation and molecular characterization from environmental sources of Rawlakot, Azad Jammu and Kashmir, Pakistan. The author is anxious for further evaluation of the pathogenic potential of the identified species and explores drinking water across Pakistan to investigate its quality and frequency of FLA, which might be a possible human hazard in future.
Fernando Gómez, Huan Zhang, Leonilde Roselli, Senjie Lin
Acta Protozoologica, Volume 60, 2021, pp. 47-59
https://doi.org/10.4467/16890027AP.21.006.15380A dinoflagellate identified as Prorocentrum dentatum, P. shikokuense or P. donghaiense is responsible of massive harmful events. Blooms of a species identified as P. shikokuense have been recently reported in the Mediterranean Sea, and an exotic origin, tentatively introduced by ballast waters from Asia, has been hypothesized. The molecular data based on the small-, large subunit, and internal transcriber spacers ribosomal RNA gene (SSU-, LSU-, ITS rRNA) sequences confirmed P. shikokuense in the Mediterranean Sea. The Mediterranean ribotype is identical to a subtropical North Atlantic ribotype, and with slight divergence from the numerous sequences from the Pacific Ocean. To revisit the relationship between P. shikokuense (=P. donghaiense) and P. obtusidens, we provide the first micrographs of P. dentatum and P. obtusidens, the latter collected from the type locality. Our observations indicate that P. dentatum, P. obtusidens, and P. shikokuense are three different species. Their diagnostic morphological characters are: Prorocentrum dentatum is 44–60 μm long, leaf-shaped, pointed and central posterior end, conspicuous anterior shoulder; P. obtusidens is 33–41 μm long, irregular parallelepiped, almost paralel valve margins, eccentric and pointed posterior end, moderate anterior shoulder; and P. shikokuense is 25 μm long, sunflower seed-shaped, round and centric posterior end, inconspicuous anterior shoulder.
Anatoly Bobrov, Clément Duckert, Edward A. D. Mitchell
Acta Protozoologica, Volume 60, 2021, pp. 61-75
https://doi.org/10.4467/16890027AP.21.007.15381Microbial diversity is known to be huge but remains only partly documented. Testate amoebae are a relatively well studied group or free-living protists that build morphologically characteristic shells on which the taxonomy of this group is mainly based. Among testate amoebae, the Hyalospheniformes are especially well documented and are a model group for microbial biogeography. Here we describe a new species of genus Certesella from Sphagnum mosses and forest litter samples collected in the Dominican Republic and Chile. We name this species Certesella larai to honour our esteemed colleague Enrique Lara. This species bears two large pores connected by tube, which are characteristic of the genera Porosia and Certesella. The new species fits best in the latter genus given the presence of a distinct, sometimes denticulated, neck with a bulge that is absent in genus Porosia but occurs in Certesella. Its elongated shape (length/breadth ratio 2.03–2.58) only overlaps with C. certesi, which is distinguishable by the presence of a distinct longitudinal groove in the neck region that is absent from the new species. Interestingly most specimens lacked the internal teeth which are usually present in members of genus Certesella. As such, while the morphology of C. larai strongly suggests a belonging to genus Certesella, molecular analyses are still required to confirm its phylogenetic position, clarify the relationships among all species in genera Porosia and Certesella and the definition and validity of these two genera. The presence of this new species in two rather distant regions – Caribbean and central Chile – suggests it is likely widespread, but possibly rare. However, this perception may be due to a sampling bias in favour of Sphagnum mosses and wet and organic-rich habitats. This illustrates the need for a more systematic sampling effort to document the full and mostly unknown taxonomic diversity of soil protists.
John R. Dolan, Jong-Kuk Moon, Eun Jin Yang
Acta Protozoologica, Volume 60, 2021, pp. 1-11
https://doi.org/10.4467/16890027AP.21.001.14061Here we summarize the results from 10 cruises in the Chukchi Sea, in August, each year from 2011 to 2020. Samples for the qualitative analysis of the microzooplankton were obtained from stations located across the Chukchi Sea using a 20μm plankton net. Conditions encountered, in terms of sea ice coverage and chlorophyll concentrations, varied widely from year to year without any obvious relationship with the composition of the microzooplankton assemblage. Examining a total of 242 samples gathered, we found a total of 44 tintinnid species (morphologically distinct forms). Plotting cumulative number of tintinnid species encountered vs cumulative number of samplings gave a typical species accumulation curve showing no sign of saturation suggesting that continued sampling in the Chukchi Sea will likely yield increases in the tintinnid species catalogue. The tintinnid species found ranged widely in lorica opening diameters (LOD) from about 11 μm to 80 μm in diameter. However, the median size of the LOD of the tintinnid assemblages varied little from year to year ranging only from about 30 μm to 40 μm. Most of the forms encountered were found in samples from only 1 or 2 cruises. Very few forms were found every year throughout the 10 years of sampling. These were 5 species of tintinnids (Acanthostomella norvegica, Leprotintinnus pellucidus, Pytchocylis obtusa, Salpingella acuminata, Salpingella faurei) and the nasselarian radiolarian Amphimelissa setosa. Examples of the morphological variability observed among individuals of Acanthostomella norvegica and Pytchocylis obtusa within single samples are shown with some individuals easily confused with forms described as other species are shown. To our knowledge, our data are the most extensive data set on Chukchi Sea microplankton. We provide all of the data recorded, which may serve as a baseline from which to assess changes projected in Arctic Sea systems, in a supplementary data file.
Piotr Solarczyk
Acta Protozoologica, Volume 60, 2021, pp. 13-20
https://doi.org/10.4467/16890027AP.21.002.14062Cyclospora is an intracellular, gastrointestinal parasite found in birds and mammals worldwide. Limited accessibility of the protozoan for experimental use, scarcity, genome heterogeneity of the isolates and narrow panel of molecular markers hamper zoonotic investigations. One of the significant limitation in zoonotic studies is the lack of precise molecular tools that would be useful in linking animal vectors as a source of human infection. Strong and convincing evidence of zoonotic features will be achieved through proper typing of Cyclospora spp. taxonomic units (e.g. species or genotypes) in animal reservoirs. The most promising method that can be employ for zoonotic surveys is next-generation sequencing.
Kaio Cesar Simiano Tavares, Maria Gabriela Casagrande Dambrós, André Saraiva Leão Antunes, Pietro Martin Danziato, Patricia Hermes Stoco, Aline Daiane Schlindwein, Renato Simões Moreira, Luiz Claudio Miletti
Acta Protozoologica, Volume 60, 2021, pp. 21-29
https://doi.org/10.4467/16890027AP.21.003.14063Selenoproteins have been described in all three domains of life and their function has been mainly associated with oxidative stress defense. Canonical elements required for selenoprotein production have been identified in members of the kinetoplastid group supporting the existence of a complete selenocysteine synthesis pathway in these organisms. Currently, nothing is known regarding the selenocysteine pathway in Trypanosoma evansi. In this study, we identified the expression of the elements selB, selC, selD, PSTK and selTRYP at the mRNA level in T. evansi. All translated proteins (selD, PSTK, selTRYP and selB) have the domains predicted and higher identity with Trypanosoma brucei. gambiense. The selenophosphate synthetase protein was localized in the cytoplasm. Our results support the existence of an active selenocysteine pathway in T. evansi.
Tuğba Sağlam, Mustafa Yaman, Ömer Ertürk
Acta Protozoologica, Volume 60, 2021, pp. 31-36
https://doi.org/10.4467/16890027AP.21.004.14064The Indian meal moth, Plodia interpunctella (Lepidoptera: Pyralidae) is one of the most important stored product pests. Fumigation plays a significant role in the management of insect pests in stored-products. However, the use of fumigants is problematic because of their effects on the environment and high costs. Entomopathogenic organisms are environmentally friendly control agents and suppress pest populations under natural conditions. In this study, distribution and occurrence of a microsporidian pathogen, Vairimorpha plodiae (Opisthokonta: Microspora) in the populations of P. interpunctella from 12 localities representing Turkey between 2019 and 2020 are presented for the first time by confirming its effectiveness on natural populations. The presence of the microsporidian pathogen was found in 11 of 12 (91.7%) populations. In total, 863 of 3,044 samples were infected by the pathogen. Infection mean was 28.4% for all populations. Our results showed that V. plodiae infection reached to a considerably high prevalence (88.77%) in P. interpunctella populations and varied from 5.1 to 88.7% between the populations. In addition, microsporidia infections have been identified throughout Turkey. We found that V. plodiae can infect all life stages of P. interpunctella. Totally, 623 (28.5%) of 2187 larvae, 14 (37.8%) of 37 pupae, 226 (27%) of 820 adults were found to be infected by the pathogen. There were considerable differences between the dead and living larvae. The microsporidian infection was found in 26 (11.6%) of 225 living larvae, whereas it was found in 595 (30.5%) of 1,952 dead larvae. These results confirm that the microsporidia pathogen has a high spreading potential in P. interpunctella populations and can be a natural biological suppression factor on pest populations.
Abida Akbar , Abdul Hameed, Abdulaziz S. Alouffi, Mashal M. Almutairi, Tania Tanveer, Abdul Matin
Acta Protozoologica, Volume 60, 2021, pp. 37-45
https://doi.org/10.4467/16890027AP.21.005.15379Naegleria belongs to the free-living amoeba family and is well-known as a human pathogen. It is recognized as etiological agent of primary amoebic meningoencephalitis involving central nervous system which always leads to death. To date, there is not a single report demonstrating Naegleria isolation and identification from environmental sources of Rawlakot, Azad Jammu and Kashmir Pakistan, and thus the aim of this study. Naegleria was isolated on non-nutrient agar plates seeded with heat killed E. coli and confirmed by morphological properties of the both stages of cyst or trophozoites. Furthermore, PCR was conducted along with direct sequencing of the PCR product for molecular identification. PCR and sequencing data verified the amplification of Naegleria sp. (07) and Vahlkampfia sp. (01) from both water and soil samples. Interestingly two species were successfully isolated and cultured on both 30 and 45°C. To the best of our knowledge this is the first report demonstrating the Naegleria isolation and molecular characterization from environmental sources of Rawlakot, Azad Jammu and Kashmir, Pakistan. The author is anxious for further evaluation of the pathogenic potential of the identified species and explores drinking water across Pakistan to investigate its quality and frequency of FLA, which might be a possible human hazard in future.
Fernando Gómez, Huan Zhang, Leonilde Roselli, Senjie Lin
Acta Protozoologica, Volume 60, 2021, pp. 47-59
https://doi.org/10.4467/16890027AP.21.006.15380A dinoflagellate identified as Prorocentrum dentatum, P. shikokuense or P. donghaiense is responsible of massive harmful events. Blooms of a species identified as P. shikokuense have been recently reported in the Mediterranean Sea, and an exotic origin, tentatively introduced by ballast waters from Asia, has been hypothesized. The molecular data based on the small-, large subunit, and internal transcriber spacers ribosomal RNA gene (SSU-, LSU-, ITS rRNA) sequences confirmed P. shikokuense in the Mediterranean Sea. The Mediterranean ribotype is identical to a subtropical North Atlantic ribotype, and with slight divergence from the numerous sequences from the Pacific Ocean. To revisit the relationship between P. shikokuense (=P. donghaiense) and P. obtusidens, we provide the first micrographs of P. dentatum and P. obtusidens, the latter collected from the type locality. Our observations indicate that P. dentatum, P. obtusidens, and P. shikokuense are three different species. Their diagnostic morphological characters are: Prorocentrum dentatum is 44–60 μm long, leaf-shaped, pointed and central posterior end, conspicuous anterior shoulder; P. obtusidens is 33–41 μm long, irregular parallelepiped, almost paralel valve margins, eccentric and pointed posterior end, moderate anterior shoulder; and P. shikokuense is 25 μm long, sunflower seed-shaped, round and centric posterior end, inconspicuous anterior shoulder.
Anatoly Bobrov, Clément Duckert, Edward A. D. Mitchell
Acta Protozoologica, Volume 60, 2021, pp. 61-75
https://doi.org/10.4467/16890027AP.21.007.15381Microbial diversity is known to be huge but remains only partly documented. Testate amoebae are a relatively well studied group or free-living protists that build morphologically characteristic shells on which the taxonomy of this group is mainly based. Among testate amoebae, the Hyalospheniformes are especially well documented and are a model group for microbial biogeography. Here we describe a new species of genus Certesella from Sphagnum mosses and forest litter samples collected in the Dominican Republic and Chile. We name this species Certesella larai to honour our esteemed colleague Enrique Lara. This species bears two large pores connected by tube, which are characteristic of the genera Porosia and Certesella. The new species fits best in the latter genus given the presence of a distinct, sometimes denticulated, neck with a bulge that is absent in genus Porosia but occurs in Certesella. Its elongated shape (length/breadth ratio 2.03–2.58) only overlaps with C. certesi, which is distinguishable by the presence of a distinct longitudinal groove in the neck region that is absent from the new species. Interestingly most specimens lacked the internal teeth which are usually present in members of genus Certesella. As such, while the morphology of C. larai strongly suggests a belonging to genus Certesella, molecular analyses are still required to confirm its phylogenetic position, clarify the relationships among all species in genera Porosia and Certesella and the definition and validity of these two genera. The presence of this new species in two rather distant regions – Caribbean and central Chile – suggests it is likely widespread, but possibly rare. However, this perception may be due to a sampling bias in favour of Sphagnum mosses and wet and organic-rich habitats. This illustrates the need for a more systematic sampling effort to document the full and mostly unknown taxonomic diversity of soil protists.
Publication date: 31.03.2021
Editor-in-Chief: Krzysztof Wiąckowski
Photo on the cover from: Vďačný P. and Foissner W. (2019) Morphology and Ontogenesis of Hemiholosticha pantanalensis nov. spec. (Ciliophora, Hypotrichia, Psilotrichidae). Acta Protozool. 58: 93-113.
Yoichiro Sogame, Katsuhiko Kojima, Toshikazu Takeshita, Shiho Kikuchi, Yuto Shimada, Rikiya Nakamura, Mikihiko Arikawa, Seiji Miyata, Eiji Kinoshita, Futoshi Suizu, Tatsuomi Matsuoka
Acta Protozoologica, Volume 59, Issue 3-4, 2020, pp. 107-120
https://doi.org/10.4467/16890027AP.20.009.13264Assays of protein contained in water-soluble fraction of encysting cells Colpoda cucullus Nag-1 by two-dimensional electrophoresis (2-D PAGE) and mass spectrometry (MS) revealed that the amount of β-tubulin abruptly increased in 2.5–10 h after encystment induction. Judging from the results that total α-tubulin content did not decrease much until 12 h after encystment induction, the result indicates that disassembly of microtubules may occur soon after encystment is induced. Therefore, we tried to visualize dynamics of microtubules. Immunofluorescence microscopy using anti-α-tubulin antibody indicated that disassembly of axonemal microtubules of cilia became within 1.5 h after encystment induction, and resorbed in 3 days. Although the cytoplasmic microtubules failed to be visualized clearly, encystmentdependent globulation of cells was promoted by taxol, an inhibitor of disassembly of microtubules. It is possible that a temporary formation of cytoplasmic microtubules may be involved in cell globulation.
The phosphorylation level of actin (43 kDa) became slightly elevated just after encystment induction. Lepidosomes, the sticky small globes surrounding encysting cells, were vividly stained with Acti-stain 555 phalloidin, suggesting that 43-kDa actin or its homologues may be contained in lepidosomes.
Odysseas A. Archontikis, Jeremy R. Young, Lluïsa Cros
Acta Protozoologica, Volume 59, Issue 3-4, 2020, pp. 121-139
https://doi.org/10.4467/16890027AP.20.010.13265The genus Anthosphaera Kamptner emend. Kleijne is one of the most taxonomically confusing modern coccolithophores and its species level taxonomy has long been in a state of flux. Based on the review of imaged specimens from our collections, we attempt to rectify the nomenclatural problems and elucidate the obfuscated taxonomy of the genus. Review of included formally and informally described species shows that they are a distinctive group with shared characters, including ten different morphotypes of probable species level. Two of these, including the type species A. fragaria, have been shown to form life-cycle associations with heterococcoliths of the Syracosphaera molischii type. Hence, all species are transferred to Syracosphaera and the new combinations S. periperforata, S. lafourcadii, and S. origami are proposed. In addition, various informally described morphotypes are now formally described as Syracosphaera molischii var. pertusa, S. periperforata var. cylindrata, S. periperforata var. tridentata, S. rotaconica, and S. elevata.
Tatsuomi Matsuoka, Yoichiro Sogame, Rikiya Nakamura, Yuya Hasegawa, Mikihiko Arikawa, Futoshi Suizu
Acta Protozoologica, Volume 59, Issue 3-4, 2020, pp. 141-147
https://doi.org/10.4467/16890027AP.20.011.13266We found that the water-rich (osmolality below 0.052 Osm/l) wet resting cysts of the soil ciliate Colpoda cucullus Nag-1 were tolerant to extremely low temperature (−65℃). When cell fluid obtained from the resting cysts was cooled at −65℃, small particles of ice crystals did not grow into large ice crystals. At −65℃, the cysts shrank due to an outflow of water, because a vapor pressure difference was produced between the cell interior and freezing surrounding medium. The osmolality of these shrunk cells was estimated 0.55 Osm/l, and the freezing point depression of the shrunk cell fluid was estimated to be 1.02℃. Hence, the antifreeze ability of wet cysts at −65℃can not be explained by freezing point depression due to elevation of cytoplasmic osmolality.
The cytoplasm of resting cysts was vividly stained red with periodic acid-Schiff (PAS) and stained purple with toluidine blue. On the other hand, the excystment-induced cysts were not stained with PAS, and exhibited a loss of the antifreeze activity. PAS staining of SDSPAGE gel obtained from encysting Colpoda cells showed that a large amount of PAS-positive macromolecules accumulated as the encystment stage progressed. These results suggest that antifreeze polysaccharides may be involved in the antifreeze activity of C. cucullus Nag-1 dormant forms.
Olga Kornilova, Klara Tsushko, Ludmila Chistyakova
Acta Protozoologica, Volume 59, Issue 3-4, 2020, pp. 149-155
https://doi.org/10.4467/16890027AP.20.012.13267This paper is a first report on species of endosymbiotic ciliates (Litostomatea, Trichostomatia) inhabiting the intestine of zebras in South Africa. Ciliates from Mountain Zebra were investigated for the first time in the world. The wild population of mountain zebras in general and the Cape Mountain Zebra subspecies in particular is low in numbers: this species is included as vulnerable in the IUCN Red List. Approximately 15 species of trichostome ciliates from 9 different genera were found in the samples collected from wild zebras in Western Cape, South Africa. Some of the ciliate species are also common to horses and other equids, while others are unique for zebras. The ciliates of Triplumaria genus common to elephants and rhinoceroses, and the species Blepharosphaera ceratotherii previously described in rhinoceroses were found in equids for the first time.
Yoichiro Sogame, Katsuhiko Kojima, Toshikazu Takeshita, Shiho Kikuchi, Yuto Shimada, Rikiya Nakamura, Mikihiko Arikawa, Seiji Miyata, Eiji Kinoshita, Futoshi Suizu, Tatsuomi Matsuoka
Acta Protozoologica, Volume 59, Issue 3-4, 2020, pp. 107-120
https://doi.org/10.4467/16890027AP.20.009.13264Assays of protein contained in water-soluble fraction of encysting cells Colpoda cucullus Nag-1 by two-dimensional electrophoresis (2-D PAGE) and mass spectrometry (MS) revealed that the amount of β-tubulin abruptly increased in 2.5–10 h after encystment induction. Judging from the results that total α-tubulin content did not decrease much until 12 h after encystment induction, the result indicates that disassembly of microtubules may occur soon after encystment is induced. Therefore, we tried to visualize dynamics of microtubules. Immunofluorescence microscopy using anti-α-tubulin antibody indicated that disassembly of axonemal microtubules of cilia became within 1.5 h after encystment induction, and resorbed in 3 days. Although the cytoplasmic microtubules failed to be visualized clearly, encystmentdependent globulation of cells was promoted by taxol, an inhibitor of disassembly of microtubules. It is possible that a temporary formation of cytoplasmic microtubules may be involved in cell globulation.
The phosphorylation level of actin (43 kDa) became slightly elevated just after encystment induction. Lepidosomes, the sticky small globes surrounding encysting cells, were vividly stained with Acti-stain 555 phalloidin, suggesting that 43-kDa actin or its homologues may be contained in lepidosomes.
Odysseas A. Archontikis, Jeremy R. Young, Lluïsa Cros
Acta Protozoologica, Volume 59, Issue 3-4, 2020, pp. 121-139
https://doi.org/10.4467/16890027AP.20.010.13265The genus Anthosphaera Kamptner emend. Kleijne is one of the most taxonomically confusing modern coccolithophores and its species level taxonomy has long been in a state of flux. Based on the review of imaged specimens from our collections, we attempt to rectify the nomenclatural problems and elucidate the obfuscated taxonomy of the genus. Review of included formally and informally described species shows that they are a distinctive group with shared characters, including ten different morphotypes of probable species level. Two of these, including the type species A. fragaria, have been shown to form life-cycle associations with heterococcoliths of the Syracosphaera molischii type. Hence, all species are transferred to Syracosphaera and the new combinations S. periperforata, S. lafourcadii, and S. origami are proposed. In addition, various informally described morphotypes are now formally described as Syracosphaera molischii var. pertusa, S. periperforata var. cylindrata, S. periperforata var. tridentata, S. rotaconica, and S. elevata.
Tatsuomi Matsuoka, Yoichiro Sogame, Rikiya Nakamura, Yuya Hasegawa, Mikihiko Arikawa, Futoshi Suizu
Acta Protozoologica, Volume 59, Issue 3-4, 2020, pp. 141-147
https://doi.org/10.4467/16890027AP.20.011.13266We found that the water-rich (osmolality below 0.052 Osm/l) wet resting cysts of the soil ciliate Colpoda cucullus Nag-1 were tolerant to extremely low temperature (−65℃). When cell fluid obtained from the resting cysts was cooled at −65℃, small particles of ice crystals did not grow into large ice crystals. At −65℃, the cysts shrank due to an outflow of water, because a vapor pressure difference was produced between the cell interior and freezing surrounding medium. The osmolality of these shrunk cells was estimated 0.55 Osm/l, and the freezing point depression of the shrunk cell fluid was estimated to be 1.02℃. Hence, the antifreeze ability of wet cysts at −65℃can not be explained by freezing point depression due to elevation of cytoplasmic osmolality.
The cytoplasm of resting cysts was vividly stained red with periodic acid-Schiff (PAS) and stained purple with toluidine blue. On the other hand, the excystment-induced cysts were not stained with PAS, and exhibited a loss of the antifreeze activity. PAS staining of SDSPAGE gel obtained from encysting Colpoda cells showed that a large amount of PAS-positive macromolecules accumulated as the encystment stage progressed. These results suggest that antifreeze polysaccharides may be involved in the antifreeze activity of C. cucullus Nag-1 dormant forms.
Olga Kornilova, Klara Tsushko, Ludmila Chistyakova
Acta Protozoologica, Volume 59, Issue 3-4, 2020, pp. 149-155
https://doi.org/10.4467/16890027AP.20.012.13267This paper is a first report on species of endosymbiotic ciliates (Litostomatea, Trichostomatia) inhabiting the intestine of zebras in South Africa. Ciliates from Mountain Zebra were investigated for the first time in the world. The wild population of mountain zebras in general and the Cape Mountain Zebra subspecies in particular is low in numbers: this species is included as vulnerable in the IUCN Red List. Approximately 15 species of trichostome ciliates from 9 different genera were found in the samples collected from wild zebras in Western Cape, South Africa. Some of the ciliate species are also common to horses and other equids, while others are unique for zebras. The ciliates of Triplumaria genus common to elephants and rhinoceroses, and the species Blepharosphaera ceratotherii previously described in rhinoceroses were found in equids for the first time.
Publication date: 2020
Editor-in-Chief: Krzysztof Wiąckowski
Photo on the cover from: Vďačný P. and Foissner W. (2019) Morphology and Ontogenesis of Hemiholosticha pantanalensis nov. spec. (Ciliophora, Hypotrichia, Psilotrichidae). Acta Protozool. 58: 93-113.
Franciane Cedrola, Marta D'agosto, Isabel Martinele, Roberto Júnio Pedroso Dias
Acta Protozoologica, Volume 59, Issue 2, 2020, pp. 61-65
https://doi.org/10.4467/16890027AP.20.005.12673The present study redescribes the species Polyplastron alaskum based on morphological characterization and provides, for the first time, data on its infraciliary bands pattern. Polyplastron alaskum was described in Alaskan dall montain sheep (Ovis dalli), and registered again only in the present study, 45 years later, inhabiting the rumen contents of domestic sheep (Ovis aries) in northeastern Brazil. All the taxonomic characters observed in the original description was observed in the present study. The infraciliary pattern in Polyplastron alaskum is slightly different of Diplodinium-type, observed in some ophryoscolecids belonging to the subfamily Diplodiniinae.
Ryota Saito, Ryota Koizumi, Tatsuya Sakai, Taiga Shimizu, Taiki Ono, Yoichiro Sogame
Acta Protozoologica, Volume 59, Issue 2, 2020, pp. 67-75
https://doi.org/10.4467/16890027AP.20.006.12674The ciliate Colpoda cucullus forms resting cysts to survive unfavorable environmental stresses. In this study, we have shown that Colpoda resting cysts survived exposure to a gamma radiation dose of 4000 Gy, although vegetative cells were killed by 500 Gy. After 4000 Gy irradiation, more than 90% of resting cysts and approximately 70% of dry cysts could excyst to form vegetative cells. In both cases, the excystment gradually increased after the induction of excystment. In addition, we also showed that protein carbonylation level was increased by gamma irradiation, but decreased by incubation in the cyst state. These results indicated that cell damage was repaired in resting cysts. Colpoda probably developed tolerance to gamma radiation by forming resting cysts as a strategy for growth in terrestrial environments, as part of contending with the stress due to reactive oxygen species caused by desiccation.
Fernando Gómez, Luis F. Artigas, Rebecca J. Gast
Acta Protozoologica, Volume 59, Issue 2, 2020, pp. 77-87
https://doi.org/10.4467/16890027AP.20.007.12675The North Sea and the English Channel are regions with a long tradition of plankton studies, where the colony-forming haptophyte Phaeocystis globosa dominates the spring phytoplankton blooms. Among its predators, we investigated an abundant unarmored dinoflagellate (~3000 cells per liter) in the North Sea in May 2019. It has been reported in the literature as Gymnodinium heterostriatum or G. striatissimum, and often identified as Gyrodinium spirale. Phylogenetic analyses using the small-, large subunit- and Internal Transcriber Spacers of the ribosomal RNA (SSU-, LSU-, ITS rRNA) gene sequences indicate that our isolates clustered within the Gyrodinium clade. The new sequences formed a sister group with sequences of the freshwater taxon Gyrodinium helveticum, being one of the infrequent marine-freshwater transitions in the microbial world. This isolate is the first characterized member of a clade of numerous environmental sequences widely distributed from cold to tropical seas. This common and abundant taxon has received several names due to its morphological plasticity (changes of size and shape, often deformed after engulfing prey) and the difficulty in discerning surface striation. We conclude that the priority is for the species name Gymnodinium heterostriatum Kofoid & Swezy 1921, a new name that was proposed for Gymnodinium spirale var. obtusum sensu Dogiel 1906. The species Gyrodinium striatissimum (Hulburt 1957) Gert Hansen & Moestrup 2000 and Gymnodinium lucidum D. Ballantine in Parke & Dixon 1964 (=G. hyalinum M. Lebour 1925) are posterior synonyms. We propose Gyrodinium heterostriatum comb. nov. for Gymnodinium heterostriatum.
Yoshiyuki Aoki, Yoichiro Sogame, Manfred Wanner, Yuri Mazei, Satoshi D. Shimano
Acta Protozoologica, Volume 59, Issue 2, 2020, pp. 99-105
https://doi.org/10.4467/16890027AP.20.008.12676A new species of a testate amoeba, Matsakision ogawaraensis sp. nov., is described from Ogawara pond, Aomori Prefecture, Japan. This is the third species in the genus Matsakision. Matsakision ogawaraensis sp. nov. is distinguished from two other species by the specific form of the shell in apertural view, which is triangular (the shells of other species are circular or elliptic). In addition, it has a chitinous lip around the aperture. For the first time, long needle-like pseudopodia have been observed.
Franciane Cedrola, Marta D'agosto, Isabel Martinele, Roberto Júnio Pedroso Dias
Acta Protozoologica, Volume 59, Issue 2, 2020, pp. 61-65
https://doi.org/10.4467/16890027AP.20.005.12673The present study redescribes the species Polyplastron alaskum based on morphological characterization and provides, for the first time, data on its infraciliary bands pattern. Polyplastron alaskum was described in Alaskan dall montain sheep (Ovis dalli), and registered again only in the present study, 45 years later, inhabiting the rumen contents of domestic sheep (Ovis aries) in northeastern Brazil. All the taxonomic characters observed in the original description was observed in the present study. The infraciliary pattern in Polyplastron alaskum is slightly different of Diplodinium-type, observed in some ophryoscolecids belonging to the subfamily Diplodiniinae.
Ryota Saito, Ryota Koizumi, Tatsuya Sakai, Taiga Shimizu, Taiki Ono, Yoichiro Sogame
Acta Protozoologica, Volume 59, Issue 2, 2020, pp. 67-75
https://doi.org/10.4467/16890027AP.20.006.12674The ciliate Colpoda cucullus forms resting cysts to survive unfavorable environmental stresses. In this study, we have shown that Colpoda resting cysts survived exposure to a gamma radiation dose of 4000 Gy, although vegetative cells were killed by 500 Gy. After 4000 Gy irradiation, more than 90% of resting cysts and approximately 70% of dry cysts could excyst to form vegetative cells. In both cases, the excystment gradually increased after the induction of excystment. In addition, we also showed that protein carbonylation level was increased by gamma irradiation, but decreased by incubation in the cyst state. These results indicated that cell damage was repaired in resting cysts. Colpoda probably developed tolerance to gamma radiation by forming resting cysts as a strategy for growth in terrestrial environments, as part of contending with the stress due to reactive oxygen species caused by desiccation.
Fernando Gómez, Luis F. Artigas, Rebecca J. Gast
Acta Protozoologica, Volume 59, Issue 2, 2020, pp. 77-87
https://doi.org/10.4467/16890027AP.20.007.12675The North Sea and the English Channel are regions with a long tradition of plankton studies, where the colony-forming haptophyte Phaeocystis globosa dominates the spring phytoplankton blooms. Among its predators, we investigated an abundant unarmored dinoflagellate (~3000 cells per liter) in the North Sea in May 2019. It has been reported in the literature as Gymnodinium heterostriatum or G. striatissimum, and often identified as Gyrodinium spirale. Phylogenetic analyses using the small-, large subunit- and Internal Transcriber Spacers of the ribosomal RNA (SSU-, LSU-, ITS rRNA) gene sequences indicate that our isolates clustered within the Gyrodinium clade. The new sequences formed a sister group with sequences of the freshwater taxon Gyrodinium helveticum, being one of the infrequent marine-freshwater transitions in the microbial world. This isolate is the first characterized member of a clade of numerous environmental sequences widely distributed from cold to tropical seas. This common and abundant taxon has received several names due to its morphological plasticity (changes of size and shape, often deformed after engulfing prey) and the difficulty in discerning surface striation. We conclude that the priority is for the species name Gymnodinium heterostriatum Kofoid & Swezy 1921, a new name that was proposed for Gymnodinium spirale var. obtusum sensu Dogiel 1906. The species Gyrodinium striatissimum (Hulburt 1957) Gert Hansen & Moestrup 2000 and Gymnodinium lucidum D. Ballantine in Parke & Dixon 1964 (=G. hyalinum M. Lebour 1925) are posterior synonyms. We propose Gyrodinium heterostriatum comb. nov. for Gymnodinium heterostriatum.
Yoshiyuki Aoki, Yoichiro Sogame, Manfred Wanner, Yuri Mazei, Satoshi D. Shimano
Acta Protozoologica, Volume 59, Issue 2, 2020, pp. 99-105
https://doi.org/10.4467/16890027AP.20.008.12676A new species of a testate amoeba, Matsakision ogawaraensis sp. nov., is described from Ogawara pond, Aomori Prefecture, Japan. This is the third species in the genus Matsakision. Matsakision ogawaraensis sp. nov. is distinguished from two other species by the specific form of the shell in apertural view, which is triangular (the shells of other species are circular or elliptic). In addition, it has a chitinous lip around the aperture. For the first time, long needle-like pseudopodia have been observed.
Publication date: 03.2020
Editor-in-Chief: Krzysztof Wiąckowski
Photo on the cover from: Vďačný P. and Foissner W. (2019) Morphology and Ontogenesis of Hemiholosticha pantanalensis nov. spec. (Ciliophora, Hypotrichia, Psilotrichidae). Acta Protozool. 58: 93-113.
Risa Ikeda, Miki Kurokawa, Momoka Murai, Noboru Saito, Motonori Ando
Acta Protozoologica, Volume 59, Issue 1, 2020, pp. 1-12
https://doi.org/10.4467/16890027AP.20.001.12157The centrohelid Raphidocystis contractilis is a heliozoan that has many radiating axopodia, each containing a bundle of microtubules. Although the rapid contraction of the axopodia at nearly a video rate (30 frames/s) is induced by mechanical stimuli, the mechanism underlying this phenomenon in R. contractilis has not yet been elucidated. In the present study, we described for the first time an adequate immunocytochemical fixation procedure for R. contractilis and the cellular distribution of α-tubulin before and after rapid axopodial contraction. We developed a flow-through chamber equipped with a micro-syringe pump that allowed the test solution to be injected at a flow rate below the threshold required to induce rapid axopodial contraction. Next, we used this injection method for evaluating the effects of different combinations of two fixatives (paraformaldehyde or glutaraldehyde) and two buffers (phosphate buffer or PHEM) on the morphological structure of the axopodia. A low concentration of glutaraldehyde in PHEM was identified as an adequate fixative for immunocytochemistry. The distribution of α-tubulin before and after rapid axopodial contraction was examined using immunocytochemistry and confocal laser scanning fluorescence microscopy. Positive signals were initially detected along the extended axopodia from the tips to the bases and were distributed in a non-uniform manner within the axopodia. Conversely, after the induction of a rapid axopodial contraction, these positive signals accumulated in the peripheral region of the cell. These results indicated that axopodial microtubules disassemble into fragments and/ or tubulin subunits during rapid axopodial contraction. Therefore, we hypothesize that the mechanism of extremely rapid axopodial contraction accompanied by cytoskeletal microtubule degradation in R. contractilis involves microtubule-severing at multiple sites.
Miroslav Macek, Ximena Sánchez Medina, Antonio Picazo, Dana Peštová, Fernando Bautista Reyes, Jorge Ricardo Montiel Hernández, Javier Alcocer, Martín Merino Ibarra, Antonio Camacho
Acta Protozoologica, Volume 59, Issue 1, 2020, pp. 13-38
https://doi.org/10.4467/16890027AP.20.002.12158The pelagic / anoxic hypolimnion population of Spirostomum teres was investigated as a part of the long-term ciliates’ monitoring (2003–2016) in an oligo- to mesotrophic monomictic hyposaline crater lake Alchichica (Puebla / Veracruz, Mexico), including an analysis of picoplankton (both heterotrophic, HPP and autotrophic, APP) and inorganic compounds of nitrogen (ammonium, nitrite, nitrate), phosphorus (dissolved reactive phosphorus, DRP) and silicon. Additionally, detailed studies of the ciliate vertical distribution and feeding activity measured upon fluorescently labelled APP (picocyanobacteria) were carried out. The results were compared with those from a neighbour freshwater crater lake La Preciosa and with a meromictic karstic lake La Cruz (Cuenca, Spain). The ciliate vertical distribution within the water column was very well defined: During the first decade, the benthic population was frequently found throughout a developing stratification of the lake. The established stratification of the lake turned the conditions favourable for the formation of an oxycline / hypolimnion population, typically, several meters below the deep chlorophyll maximum (formed basically by diatoms); the population preferred the layers without detectable dissolved oxygen. However, an observed gradient of light (PAR) could support both oxygenic and anoxygenic photosynthesis. Late stratification after deepening of the thermocline reduced the layers with S. teres population to a minimum apparently due to the drastic change in physicochemical conditions within a metalimnion, coupled with an oxycline, and limited to 1 to 2 meters; microstratification was found. Last years, the very bottom population disappeared or it was reduced and the late stratification S. teres peaks were smaller or did not appeared. Generally, S. teres oxycline / anoxic hypolimnion population was observed from June through November. Optimum picoplankton numbers in conditions that supported the ciliate growth were found: The ciliate was peaking at APP of 0.6 to 1 × 105 cells mL–1; the optimum of HPP was observed round 1.4 × 106 cells mL–1. S. teres was efficiently feeding upon picocyanobacteria in numbers of 105 cells mL–1 reaching the clearance rate of 2000 nL cell–1h–1, which represented in average 130 to 210 cells cell–1h–1 ingested. Feeding upon purple sulphur bacteria was observed but only during the end of the lake stable stratification when the ciliate population was already dropping. On the other hand, the volume specific clearance of S. teres upon picocyanobacteria (103 h–1) did not support the hypothesis that they could serve as a sole prey. Feeding upon eukaryote phytoplankton (chlorophytes Monoraphidium minutum, diatoms Cyclotella choc tawhatcheeana) could be of higher importance that previously supposed. Additionally, a use of ingested and retained photosynthetic prokaryotes is hypothesized.
Anupma Garg, Anshu Chaudhary, Abhishek Gupta, Abhinav Kumar, Bindu Sharma, Hridaya Shanker Singh
Acta Protozoologica, Volume 59, Issue 1, 2020, pp. 39-53
https://doi.org/10.4467/16890027AP.20.003.12159In Indian freshwater fish myxosporean infections are among the most cosmopolitan parasites, they are relatively well studied morphologically but their phylogenetic relationships were unclear and the genetic data is limited only to a few species. The study aims to present molecular data for two myxosporean species, Henneguya namae Haldar et al. 1983 and Myxobolus sophorae Jayasri, 1982 collected from Indian freshwater fish, the elongate glass-perchlet Chanda nama (=Ambassis nama) and pool barb Puntius sophore, respectively. In the present study molecular data are provided for H. namae and M. sophorae using nested PCR. The obtained partial 18S rDNA gene sequences were analyzed using maximum likelihood (ML) and Bayesian inference (BI) methods. The 18S rDNA gene sequences of H. namae showed similarity with the sequences of H. chaudhuryi, Henneguya sp. RA-2015, H. voronini and H. setiuensis about 72.1 to 78% and M. sophorae with Myxobolus ticto was about 90% respectively. The aim of this paper was to identify H. namae and M. sophorae morphologically and using molecular methods.
Shinji Yamane, Maho Watanabe, Ryoji Funadani, Ryutaro Miyazaki, Yuya Hasegawa, Mikihiko Arikawa, Futoshi Suizu, Kou Matsuoka, Tatsuomi Matsuoka
Acta Protozoologica, Volume 59, Issue 1, 2020, pp. 55-60
https://doi.org/10.4467/16890027AP.20.004.12160Resting cysts of the terrestrial ciliate Colpoda cucullus (Nag-1 strain) are highly resistant to UV light. It has been speculated that auto-fluorescent (blue fluorescent) particles surrounding the nuclei and yellowish fluorescent layers of the cyst wall are the candidate structures for the protection of the cellular components from UV light. The UV resistance of encysting cells was quickly acquired up to 5 h after the onset of encystment induction, and then gradually increased for several days. The less fluorescent ectocyst layer, yellowish fluorescent first-synthesized endocyst layer (en-1) and the NSPs were formed within 5 h after the onset of encystment induction, and thereafter endocyst layers became gradually thicker for several days. The cyst wall sample (ectocyst and endocyst layers) markedly absorbed a broad range of UV light. This result indicates that the cyst wall evidently has UV-cut function. These results support that the cyst wall and NSPs of C. cucullus play a role in the shielding of the cell components from UV light.
Risa Ikeda, Miki Kurokawa, Momoka Murai, Noboru Saito, Motonori Ando
Acta Protozoologica, Volume 59, Issue 1, 2020, pp. 1-12
https://doi.org/10.4467/16890027AP.20.001.12157The centrohelid Raphidocystis contractilis is a heliozoan that has many radiating axopodia, each containing a bundle of microtubules. Although the rapid contraction of the axopodia at nearly a video rate (30 frames/s) is induced by mechanical stimuli, the mechanism underlying this phenomenon in R. contractilis has not yet been elucidated. In the present study, we described for the first time an adequate immunocytochemical fixation procedure for R. contractilis and the cellular distribution of α-tubulin before and after rapid axopodial contraction. We developed a flow-through chamber equipped with a micro-syringe pump that allowed the test solution to be injected at a flow rate below the threshold required to induce rapid axopodial contraction. Next, we used this injection method for evaluating the effects of different combinations of two fixatives (paraformaldehyde or glutaraldehyde) and two buffers (phosphate buffer or PHEM) on the morphological structure of the axopodia. A low concentration of glutaraldehyde in PHEM was identified as an adequate fixative for immunocytochemistry. The distribution of α-tubulin before and after rapid axopodial contraction was examined using immunocytochemistry and confocal laser scanning fluorescence microscopy. Positive signals were initially detected along the extended axopodia from the tips to the bases and were distributed in a non-uniform manner within the axopodia. Conversely, after the induction of a rapid axopodial contraction, these positive signals accumulated in the peripheral region of the cell. These results indicated that axopodial microtubules disassemble into fragments and/ or tubulin subunits during rapid axopodial contraction. Therefore, we hypothesize that the mechanism of extremely rapid axopodial contraction accompanied by cytoskeletal microtubule degradation in R. contractilis involves microtubule-severing at multiple sites.
Miroslav Macek, Ximena Sánchez Medina, Antonio Picazo, Dana Peštová, Fernando Bautista Reyes, Jorge Ricardo Montiel Hernández, Javier Alcocer, Martín Merino Ibarra, Antonio Camacho
Acta Protozoologica, Volume 59, Issue 1, 2020, pp. 13-38
https://doi.org/10.4467/16890027AP.20.002.12158The pelagic / anoxic hypolimnion population of Spirostomum teres was investigated as a part of the long-term ciliates’ monitoring (2003–2016) in an oligo- to mesotrophic monomictic hyposaline crater lake Alchichica (Puebla / Veracruz, Mexico), including an analysis of picoplankton (both heterotrophic, HPP and autotrophic, APP) and inorganic compounds of nitrogen (ammonium, nitrite, nitrate), phosphorus (dissolved reactive phosphorus, DRP) and silicon. Additionally, detailed studies of the ciliate vertical distribution and feeding activity measured upon fluorescently labelled APP (picocyanobacteria) were carried out. The results were compared with those from a neighbour freshwater crater lake La Preciosa and with a meromictic karstic lake La Cruz (Cuenca, Spain). The ciliate vertical distribution within the water column was very well defined: During the first decade, the benthic population was frequently found throughout a developing stratification of the lake. The established stratification of the lake turned the conditions favourable for the formation of an oxycline / hypolimnion population, typically, several meters below the deep chlorophyll maximum (formed basically by diatoms); the population preferred the layers without detectable dissolved oxygen. However, an observed gradient of light (PAR) could support both oxygenic and anoxygenic photosynthesis. Late stratification after deepening of the thermocline reduced the layers with S. teres population to a minimum apparently due to the drastic change in physicochemical conditions within a metalimnion, coupled with an oxycline, and limited to 1 to 2 meters; microstratification was found. Last years, the very bottom population disappeared or it was reduced and the late stratification S. teres peaks were smaller or did not appeared. Generally, S. teres oxycline / anoxic hypolimnion population was observed from June through November. Optimum picoplankton numbers in conditions that supported the ciliate growth were found: The ciliate was peaking at APP of 0.6 to 1 × 105 cells mL–1; the optimum of HPP was observed round 1.4 × 106 cells mL–1. S. teres was efficiently feeding upon picocyanobacteria in numbers of 105 cells mL–1 reaching the clearance rate of 2000 nL cell–1h–1, which represented in average 130 to 210 cells cell–1h–1 ingested. Feeding upon purple sulphur bacteria was observed but only during the end of the lake stable stratification when the ciliate population was already dropping. On the other hand, the volume specific clearance of S. teres upon picocyanobacteria (103 h–1) did not support the hypothesis that they could serve as a sole prey. Feeding upon eukaryote phytoplankton (chlorophytes Monoraphidium minutum, diatoms Cyclotella choc tawhatcheeana) could be of higher importance that previously supposed. Additionally, a use of ingested and retained photosynthetic prokaryotes is hypothesized.
Anupma Garg, Anshu Chaudhary, Abhishek Gupta, Abhinav Kumar, Bindu Sharma, Hridaya Shanker Singh
Acta Protozoologica, Volume 59, Issue 1, 2020, pp. 39-53
https://doi.org/10.4467/16890027AP.20.003.12159In Indian freshwater fish myxosporean infections are among the most cosmopolitan parasites, they are relatively well studied morphologically but their phylogenetic relationships were unclear and the genetic data is limited only to a few species. The study aims to present molecular data for two myxosporean species, Henneguya namae Haldar et al. 1983 and Myxobolus sophorae Jayasri, 1982 collected from Indian freshwater fish, the elongate glass-perchlet Chanda nama (=Ambassis nama) and pool barb Puntius sophore, respectively. In the present study molecular data are provided for H. namae and M. sophorae using nested PCR. The obtained partial 18S rDNA gene sequences were analyzed using maximum likelihood (ML) and Bayesian inference (BI) methods. The 18S rDNA gene sequences of H. namae showed similarity with the sequences of H. chaudhuryi, Henneguya sp. RA-2015, H. voronini and H. setiuensis about 72.1 to 78% and M. sophorae with Myxobolus ticto was about 90% respectively. The aim of this paper was to identify H. namae and M. sophorae morphologically and using molecular methods.
Shinji Yamane, Maho Watanabe, Ryoji Funadani, Ryutaro Miyazaki, Yuya Hasegawa, Mikihiko Arikawa, Futoshi Suizu, Kou Matsuoka, Tatsuomi Matsuoka
Acta Protozoologica, Volume 59, Issue 1, 2020, pp. 55-60
https://doi.org/10.4467/16890027AP.20.004.12160Resting cysts of the terrestrial ciliate Colpoda cucullus (Nag-1 strain) are highly resistant to UV light. It has been speculated that auto-fluorescent (blue fluorescent) particles surrounding the nuclei and yellowish fluorescent layers of the cyst wall are the candidate structures for the protection of the cellular components from UV light. The UV resistance of encysting cells was quickly acquired up to 5 h after the onset of encystment induction, and then gradually increased for several days. The less fluorescent ectocyst layer, yellowish fluorescent first-synthesized endocyst layer (en-1) and the NSPs were formed within 5 h after the onset of encystment induction, and thereafter endocyst layers became gradually thicker for several days. The cyst wall sample (ectocyst and endocyst layers) markedly absorbed a broad range of UV light. This result indicates that the cyst wall evidently has UV-cut function. These results support that the cyst wall and NSPs of C. cucullus play a role in the shielding of the cell components from UV light.
Publication date: 23.12.2019
Editor-in-Chief: Krzysztof Wiąckowski
Photo on the cover fromr: De Jager G. P., Basson L., Van Marwijk J. (2019) A New Trichodina Species (Peritrichia: Mobilida) from Anuran Tadpole Hosts, Sclerophrys spp. in the Okavango Panhandle, Botswana, with Comments on this Taxon. Acta Protozool. 58: 141-153.
Won Je Lee
Acta Protozoologica, Volume 58, Issue 4, 2019, pp. 167-189
https://doi.org/10.4467/16890027AP.19.016.12018A total of 155 species and 75 genera were found at marine sediments in Sydney region (Australia) and are described using light microscopy: 117 species at Port Botany, 111 species at Kogarah Bay, 94 species at Woolooware Bay, 126 species at Quibray Bay, 74 species at Avoca beach, 48 species at Watsons Bay. The records include accounts of 15 unidentified taxa and two new taxa: Eoramonas jungensis sp. nov. (Eoramonas gen. nov.), Protaspa flexibilis sp. nov. Most flagellates described here have been found at other locations worldwide, but many species not reported from any other locations. I am unable to assess if these species are endemic because of the lack of intensive studies elsewhere. However, these results suggest that the flagellate communities from Botany Bay are distinctive.
Jingbao Li, Keqing Wen , Erkang Zhu , Jingyi Wang
Acta Protozoologica, Volume 58, Issue 4, 2019, pp. 191-200
https://doi.org/10.4467/16890027AP.19.017.12019A soil urostylid ciliate Extraholosticha sylvatica, isolated from southern China, is studied using live observation and protargol impregnation. The main ontogenetic features of E. sylvatica are as follows: (a) in the proter, only the posterior part of the parental adoral zone of membranelles is renewed, while the anterior portion is retained; undulating membranes anlage undergo, like most hypotrichs, depolymerization of old undulating membranes and differentiation of new structures; (b) the oral primordium in the opisthe and the frontoventraltransverse cirral anlagen in both daughter cells are formed with contribution of the parental midventral cirri; (c) three frontal, one buccal, three to five frontoventral, one or two frontoterminal, two or three pretransverse ventral and six to 11 transverse cirri and 16–22 midventral pairs are generated from frontoventral-transverse cirral anlagen; (d) in both the left and the right marginal rows as well as the dorsal kineties, each two anlagen are formed intrakinetally; three to six caudal cirri are formed at the posterior end of the 5th dorsal kinety anlage; (e) the macronuclear nodules fuse into a single mass during the process.
Najla Baković, Ferry J. Siemensma , Robert Baković, Josip Rubinić
Acta Protozoologica, Volume 58, Issue 4, 2019, pp. 201-215
https://doi.org/10.4467/16890027AP.19.018.12020Karst freshwater caves are subterranean habitats characterized by the constant absence of light and relatively small variations of temperature and air humidity. They are mostly food deprived environments, with the exception if large bat colonies are present or if they are intensively supplied with organic matter by sinking rivers. Even though these habitats are often described as harsh, they have enabled the evolution of highly specialized and often endemic animals. The cave eukaryotic micro-organisms, on the other hand, are scarcely researched. The results of research of testate amoebae in the caves of the Dinaric arc detected 23 species, 12 of which were first found in caves. Also, a description of Centropyxis bipilata sp. nov. is presented. This species is clearly distinguished from other described species based on shell size, the presence of two struts and the usually dark ring around the aperture. Testate amoebae were registered on aquatic and terrestrial cave sediments and transitional habitats (like hygropetric and wet walls). The most frequent species within the samples were: Trinema lineare, Cryptodifflugia oviformis and Centropyxis bipilata sp. nov. Maximum diversity of testate amoebae was registered in Ponor Kovači with twenty species. In 24.4 % of the investigated samples microphototrophs were found, implying good surface-subsurface connectivity that could also affect testate amoebae diversity. This research showed that caves are underestimated habitats that can provide us with new data about the testate amoebae biogeography and diversity.
Giulia M. Ribeiro, Paulo Inácio Prado , Renato Mendes Coutinho , Marina Costa Rillo , Samuel Pereira Junior, Alfredo L. Porfírio-Sousa, Daniel J. G. Lahr
Acta Protozoologica, Volume 58, Issue 4, 2019, pp. 217-233
https://doi.org/10.4467/16890027AP.19.019.12021Coexistence usually are exceeding the explicable rate by competitive exclusion principle. Since the pioneer Gause, many studies have used protist microcosm systems to study competitive exclusion. We explored a two-species system with the testate-amoebae: (Arcella intermedia and Pyxidicula operculata), where competitive exclusion is expected to occur. We determined their growth curves individually and under competitive interaction. We used a state-space model to represent system dynamics and calculated posterior population sizes simulating competition dynamics. Contrarily to our expectation, Arcella and Pyxidicula showed similar growth rates (1.37 and 1.46 days–1 respectively) and only different carrying capacity (1,997 and 25,108 cells cm–2 respectively). The maximum number of cells of both species when growing in competition was much lower if compared to the monospecific cultures (in average, 73% and 80% less for Arcella and Pyxidicula respectively). However, our competition experiments always resulted in coexistence. According to the models, the drop in growth rates and stochasticity mainly explains our coexistence results. We propose that a context of ephemeral resources can explain these results. Additionally, we propose generating factors of stochasticity as intraspecific variation, small population effects, toxicity of waste products and influence of the bacterial community.
Won Je Lee
Acta Protozoologica, Volume 58, Issue 4, 2019, pp. 167-189
https://doi.org/10.4467/16890027AP.19.016.12018A total of 155 species and 75 genera were found at marine sediments in Sydney region (Australia) and are described using light microscopy: 117 species at Port Botany, 111 species at Kogarah Bay, 94 species at Woolooware Bay, 126 species at Quibray Bay, 74 species at Avoca beach, 48 species at Watsons Bay. The records include accounts of 15 unidentified taxa and two new taxa: Eoramonas jungensis sp. nov. (Eoramonas gen. nov.), Protaspa flexibilis sp. nov. Most flagellates described here have been found at other locations worldwide, but many species not reported from any other locations. I am unable to assess if these species are endemic because of the lack of intensive studies elsewhere. However, these results suggest that the flagellate communities from Botany Bay are distinctive.
Jingbao Li, Keqing Wen , Erkang Zhu , Jingyi Wang
Acta Protozoologica, Volume 58, Issue 4, 2019, pp. 191-200
https://doi.org/10.4467/16890027AP.19.017.12019A soil urostylid ciliate Extraholosticha sylvatica, isolated from southern China, is studied using live observation and protargol impregnation. The main ontogenetic features of E. sylvatica are as follows: (a) in the proter, only the posterior part of the parental adoral zone of membranelles is renewed, while the anterior portion is retained; undulating membranes anlage undergo, like most hypotrichs, depolymerization of old undulating membranes and differentiation of new structures; (b) the oral primordium in the opisthe and the frontoventraltransverse cirral anlagen in both daughter cells are formed with contribution of the parental midventral cirri; (c) three frontal, one buccal, three to five frontoventral, one or two frontoterminal, two or three pretransverse ventral and six to 11 transverse cirri and 16–22 midventral pairs are generated from frontoventral-transverse cirral anlagen; (d) in both the left and the right marginal rows as well as the dorsal kineties, each two anlagen are formed intrakinetally; three to six caudal cirri are formed at the posterior end of the 5th dorsal kinety anlage; (e) the macronuclear nodules fuse into a single mass during the process.
Najla Baković, Ferry J. Siemensma , Robert Baković, Josip Rubinić
Acta Protozoologica, Volume 58, Issue 4, 2019, pp. 201-215
https://doi.org/10.4467/16890027AP.19.018.12020Karst freshwater caves are subterranean habitats characterized by the constant absence of light and relatively small variations of temperature and air humidity. They are mostly food deprived environments, with the exception if large bat colonies are present or if they are intensively supplied with organic matter by sinking rivers. Even though these habitats are often described as harsh, they have enabled the evolution of highly specialized and often endemic animals. The cave eukaryotic micro-organisms, on the other hand, are scarcely researched. The results of research of testate amoebae in the caves of the Dinaric arc detected 23 species, 12 of which were first found in caves. Also, a description of Centropyxis bipilata sp. nov. is presented. This species is clearly distinguished from other described species based on shell size, the presence of two struts and the usually dark ring around the aperture. Testate amoebae were registered on aquatic and terrestrial cave sediments and transitional habitats (like hygropetric and wet walls). The most frequent species within the samples were: Trinema lineare, Cryptodifflugia oviformis and Centropyxis bipilata sp. nov. Maximum diversity of testate amoebae was registered in Ponor Kovači with twenty species. In 24.4 % of the investigated samples microphototrophs were found, implying good surface-subsurface connectivity that could also affect testate amoebae diversity. This research showed that caves are underestimated habitats that can provide us with new data about the testate amoebae biogeography and diversity.
Giulia M. Ribeiro, Paulo Inácio Prado , Renato Mendes Coutinho , Marina Costa Rillo , Samuel Pereira Junior, Alfredo L. Porfírio-Sousa, Daniel J. G. Lahr
Acta Protozoologica, Volume 58, Issue 4, 2019, pp. 217-233
https://doi.org/10.4467/16890027AP.19.019.12021Coexistence usually are exceeding the explicable rate by competitive exclusion principle. Since the pioneer Gause, many studies have used protist microcosm systems to study competitive exclusion. We explored a two-species system with the testate-amoebae: (Arcella intermedia and Pyxidicula operculata), where competitive exclusion is expected to occur. We determined their growth curves individually and under competitive interaction. We used a state-space model to represent system dynamics and calculated posterior population sizes simulating competition dynamics. Contrarily to our expectation, Arcella and Pyxidicula showed similar growth rates (1.37 and 1.46 days–1 respectively) and only different carrying capacity (1,997 and 25,108 cells cm–2 respectively). The maximum number of cells of both species when growing in competition was much lower if compared to the monospecific cultures (in average, 73% and 80% less for Arcella and Pyxidicula respectively). However, our competition experiments always resulted in coexistence. According to the models, the drop in growth rates and stochasticity mainly explains our coexistence results. We propose that a context of ephemeral resources can explain these results. Additionally, we propose generating factors of stochasticity as intraspecific variation, small population effects, toxicity of waste products and influence of the bacterial community.
Publication date: 24.09.2019
Editor-in-Chief: Krzysztof Wiąckowski
Photo on the cover fromr: De Jager G. P., Basson L., Van Marwijk J. (2019) A New Trichodina Species (Peritrichia: Mobilida) from Anuran Tadpole Hosts, Sclerophrys spp. in the Okavango Panhandle, Botswana, with Comments on this Taxon. Acta Protozool. 58: 141-153.
Peter Vďačný, Wilhelm Foissner
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 93-113
https://doi.org/10.4467/16890027AP.19.010.11419The morphology and ontogenesis of a new psilotrichid ciliate, Hemiholosticha pantanalensis, were studied using live observation, protargol impregnation, and scanning electron microscopy. Diagnostic features of the new species include: a medium-sized, almost circular to broadly obovate body with a short anterior projection; two macronuclear nodules with a single micronucleus in between; a total of about 35 cirri arranged in three ventral, one postoral, one right and one left marginal row; three dorsal kineties extending along prominent ribs; an adoral zone occupying about 60% of body length; and intracellular, eyespot-bearing, green algae almost filling the body. The ontogenesis of H. pantanalensis follows the psilotrichid mode, being a mixture of features found not only in various hypotrich taxa but also in other spirotrich groups. Specifically, the oral primordium develops in a deep pouch as in euplotids and oligotrichs, the anlage for the undulating membranes does not produce cirri as in euplotids and some schmidingerothrichids, and the longitudinal ventral cirral row R3 develops from two anlagen as in some amphisiellids and kahliellids. Since psilotrichids are classified in a polytomy of main hypotrich lineages in 18S rRNA gene phylogenies, some of their ontogenetic features might be ancient spirotrich plesiomorphies while others might be homoplasies.
Fernando Gómez, Yasuhide Nakamura , Luis F. Artigas
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 115-124
https://doi.org/10.4467/16890027AP.19.012.11421The molecular phylogeny of the sand-dwelling dinoflagellate Planodinium striatum was investigated from isolates collected in the NE English Channel. In the SSU rRNA gene phylogeny, the sequences of Planodinium clustered with the type species of Plagiodinium, P. belizeanum, and more distantly related to Plagiodinium ballux. Although the SSU rRNA gene sequences of Planodinium showed a high percentage of identity (96%) with partial sequences of species of Podolampas (~1200 base pairs), the SSU rRNA gene phylogenies did not show a relationship with the clade of the Podolampadaceae (Podolampas, Blepharocysta, Roscoffia), neither with the sequences of the sanddwelling genus Cabra. The SSU rRNA gene sequences of Plagiodinium belizeanum and P. ballux showed a low percentage of identity (96%) clustering in separate clades in the SSU rRNA gene phylogeny with Planodinium. The morphology of P. ballux and its generic type differed in the plate arrangement and the morphology of the cingulum, amongst other features. Based on the morphological and molecular differences, we propose the new genus Chrysodinium gen. nov. for P. ballux, with the re-interpreted thecal plate formula Po 3’ 1’’ 7c 2s 5’’’ 1’’’’.
Gerhard P. de Jager, Linda Basson
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 125-139
https://doi.org/10.4467/16890027AP.19.013.11914Trichodina heterodentata was first described from fish breeding farms in the Philippines by Bryan Duncan in 1977 as ectoparasites of imported cichlids, more specifically the southern African Oreochromis mossambicus (Peters, 1852) from the Limpopo River System. This trichodinid has subsequently been described from almost every continent, bar North America. Being a cosmopolitan species, with a preference for cichlid hosts, it has unambiguous morphological features, but with distinct variances between and within populations. After reviewing previous descriptions of North American trichodinids, analysing the morphological data (both generally published information along with the original type material from the Smithsonian Museum, Washington, U.S.A.) and investigating the distribution patterns of the southern African introduced O. mossambicus throughout the North American water systems, three of the four studied trichodinids (T. hypsilepis Wellborn, 1967, T. salmincola Wellborn, 1967 and T. vallata Wellborn, 1967) are proposed to represent the same species as T. heterodentata. According to nomenclature rules T. hypsilepis henceforth represents the valid taxon (synonyms: T. salmincola, T. vallata and T. heterodentata). This not only questions the validity of several trichodinid species, but also indicates the probability of an African alien introduction into North America.
Gerhard P. de Jager, Linda Basson, Jacqueline van Marwijk
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 141-153
https://doi.org/10.4467/16890027AP.19.014.11915Mobiline taxonomic data is mostly inferred from populations collected in and on hosts associated with aquaculture. Even though these conditions may be conducive for studies relating to the hosts, accurate taxonomic inferences of the symbionts will be problematic. The site for the present study was the Okavango Panhandle region in Northern Botswana, an isolated, natural area with minimal anthropogenic influences. Morphometric and molecular evidence revealed that anuran tadpole trichodinids, up to now reported as Trichodina heterodentata Duncan 1977 and T. hypsilepis Wellborn 1967 from multiple host types, are in fact a new, more host specific species. This study includes comprehensive denticle descriptions of both the anuran hosted trichodinid and the morphologically similar T. hypsilepis restricted to teleost hosts (previously T. heterodentata).
Carlos Alberto Durán-Ramirez, Rosaura Mayén-Estrada, Víctor Manuel Romero-Niembro
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 155-165
https://doi.org/10.4467/16890027AP.19.015.11916To understand distributional and ecological aspects of ciliates living in tank bromeliads, we analyzed the ciliate community structure in fifteen different epiphytic and terrestrial bromeliad species from different types of vegetation. Sixty-nine samples were collected from plants of genera Aechmea, Bromelia, Pseudalcantarea and Tillandsia in seven localities in eastern Mexico during 2014 and 2015. The sampling localities covered an altitude gradient from 0 till 2 210 m ASL. We found 24 ciliate species and through the application of a principal component analysis, three clusters that correspond to several types of vegetation were obtained with regard to ciliate and bromeliad species. We recorded the largest number of ciliate species in localities of montane cloud forest, and also the largest number of ciliate species endemic to tank bromeliads, like Glaucomides bromelicola, inhabiting bromeliads from this forest. We observed the presence of ciliates in Bromelia pinguin that possesses a weakly developed phytotelm. The results of our study indicate that the species composition of ciliates inhabiting tank bromeliads depends on such correlated environmental factors like altitude ASL, temperature and type of vegetation.
Peter Vďačný, Wilhelm Foissner
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 93-113
https://doi.org/10.4467/16890027AP.19.010.11419The morphology and ontogenesis of a new psilotrichid ciliate, Hemiholosticha pantanalensis, were studied using live observation, protargol impregnation, and scanning electron microscopy. Diagnostic features of the new species include: a medium-sized, almost circular to broadly obovate body with a short anterior projection; two macronuclear nodules with a single micronucleus in between; a total of about 35 cirri arranged in three ventral, one postoral, one right and one left marginal row; three dorsal kineties extending along prominent ribs; an adoral zone occupying about 60% of body length; and intracellular, eyespot-bearing, green algae almost filling the body. The ontogenesis of H. pantanalensis follows the psilotrichid mode, being a mixture of features found not only in various hypotrich taxa but also in other spirotrich groups. Specifically, the oral primordium develops in a deep pouch as in euplotids and oligotrichs, the anlage for the undulating membranes does not produce cirri as in euplotids and some schmidingerothrichids, and the longitudinal ventral cirral row R3 develops from two anlagen as in some amphisiellids and kahliellids. Since psilotrichids are classified in a polytomy of main hypotrich lineages in 18S rRNA gene phylogenies, some of their ontogenetic features might be ancient spirotrich plesiomorphies while others might be homoplasies.
Fernando Gómez, Yasuhide Nakamura , Luis F. Artigas
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 115-124
https://doi.org/10.4467/16890027AP.19.012.11421The molecular phylogeny of the sand-dwelling dinoflagellate Planodinium striatum was investigated from isolates collected in the NE English Channel. In the SSU rRNA gene phylogeny, the sequences of Planodinium clustered with the type species of Plagiodinium, P. belizeanum, and more distantly related to Plagiodinium ballux. Although the SSU rRNA gene sequences of Planodinium showed a high percentage of identity (96%) with partial sequences of species of Podolampas (~1200 base pairs), the SSU rRNA gene phylogenies did not show a relationship with the clade of the Podolampadaceae (Podolampas, Blepharocysta, Roscoffia), neither with the sequences of the sanddwelling genus Cabra. The SSU rRNA gene sequences of Plagiodinium belizeanum and P. ballux showed a low percentage of identity (96%) clustering in separate clades in the SSU rRNA gene phylogeny with Planodinium. The morphology of P. ballux and its generic type differed in the plate arrangement and the morphology of the cingulum, amongst other features. Based on the morphological and molecular differences, we propose the new genus Chrysodinium gen. nov. for P. ballux, with the re-interpreted thecal plate formula Po 3’ 1’’ 7c 2s 5’’’ 1’’’’.
Gerhard P. de Jager, Linda Basson
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 125-139
https://doi.org/10.4467/16890027AP.19.013.11914Trichodina heterodentata was first described from fish breeding farms in the Philippines by Bryan Duncan in 1977 as ectoparasites of imported cichlids, more specifically the southern African Oreochromis mossambicus (Peters, 1852) from the Limpopo River System. This trichodinid has subsequently been described from almost every continent, bar North America. Being a cosmopolitan species, with a preference for cichlid hosts, it has unambiguous morphological features, but with distinct variances between and within populations. After reviewing previous descriptions of North American trichodinids, analysing the morphological data (both generally published information along with the original type material from the Smithsonian Museum, Washington, U.S.A.) and investigating the distribution patterns of the southern African introduced O. mossambicus throughout the North American water systems, three of the four studied trichodinids (T. hypsilepis Wellborn, 1967, T. salmincola Wellborn, 1967 and T. vallata Wellborn, 1967) are proposed to represent the same species as T. heterodentata. According to nomenclature rules T. hypsilepis henceforth represents the valid taxon (synonyms: T. salmincola, T. vallata and T. heterodentata). This not only questions the validity of several trichodinid species, but also indicates the probability of an African alien introduction into North America.
Gerhard P. de Jager, Linda Basson, Jacqueline van Marwijk
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 141-153
https://doi.org/10.4467/16890027AP.19.014.11915Mobiline taxonomic data is mostly inferred from populations collected in and on hosts associated with aquaculture. Even though these conditions may be conducive for studies relating to the hosts, accurate taxonomic inferences of the symbionts will be problematic. The site for the present study was the Okavango Panhandle region in Northern Botswana, an isolated, natural area with minimal anthropogenic influences. Morphometric and molecular evidence revealed that anuran tadpole trichodinids, up to now reported as Trichodina heterodentata Duncan 1977 and T. hypsilepis Wellborn 1967 from multiple host types, are in fact a new, more host specific species. This study includes comprehensive denticle descriptions of both the anuran hosted trichodinid and the morphologically similar T. hypsilepis restricted to teleost hosts (previously T. heterodentata).
Carlos Alberto Durán-Ramirez, Rosaura Mayén-Estrada, Víctor Manuel Romero-Niembro
Acta Protozoologica, Volume 58, Issue 3, 2019, pp. 155-165
https://doi.org/10.4467/16890027AP.19.015.11916To understand distributional and ecological aspects of ciliates living in tank bromeliads, we analyzed the ciliate community structure in fifteen different epiphytic and terrestrial bromeliad species from different types of vegetation. Sixty-nine samples were collected from plants of genera Aechmea, Bromelia, Pseudalcantarea and Tillandsia in seven localities in eastern Mexico during 2014 and 2015. The sampling localities covered an altitude gradient from 0 till 2 210 m ASL. We found 24 ciliate species and through the application of a principal component analysis, three clusters that correspond to several types of vegetation were obtained with regard to ciliate and bromeliad species. We recorded the largest number of ciliate species in localities of montane cloud forest, and also the largest number of ciliate species endemic to tank bromeliads, like Glaucomides bromelicola, inhabiting bromeliads from this forest. We observed the presence of ciliates in Bromelia pinguin that possesses a weakly developed phytotelm. The results of our study indicate that the species composition of ciliates inhabiting tank bromeliads depends on such correlated environmental factors like altitude ASL, temperature and type of vegetation.
Publication date: 31.10.2019
Editor-in-Chief: Krzysztof Wiąckowski
Photo on the cover fromr: De Jager G. P., Basson L., Van Marwijk J. (2019) A New Trichodina Species (Peritrichia: Mobilida) from Anuran Tadpole Hosts, Sclerophrys spp. in the Okavango Panhandle, Botswana, with Comments on this Taxon. Acta Protozool. 58: 141-153.
Kang-San Kim, Kyu-Seok Chae, Gi-Sik Min
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 43-51
https://doi.org/10.4467/16890027AP.19.005.10836A new marine urostylid ciliate, Arcuseries minima sp. nov., was discovered in South Korea. Morphological observations and molecular phylogenetic analyses based on small subunit ribosomal DNA (18S rDNA) sequences were used to describe the new species. Arcuseries minima is most similar to A. scutellum among all Arcuseries species, but differs in the following main characters: number of adoral membranelles (13–16 vs. 17 or 18), cortical granules (yellowish, clustered around cirri and dorsal bristles vs. colorless, irregularly scattered), number of macronuclear nodules (20–27 vs. 42–90), number of midventral cirri (5–10 vs. 12–14), and number f transverse cirri (5 or 6 vs. 8). The new species and A. scutellum differ from A. petzi and A. warreni in having smaller body size (≤80 μm vs. ≥80 μm) and fewer cirri: left marginal (≤ 17 vs. ≥ 18) and transverse (≤ 8 vs. ≥8) cirri. This relationship was supported by the phylogenetic tree, where these two groups were separated into two branches.
Ľubomír Rajter, William Bourland, Peter Vďačný
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 53-68
https://doi.org/10.4467/16890027AP.19.004.10835The morphology and phylogenetic position of a haptorian ciliate, Phialina pupula (Müller, 1773) Foissner, 1983, isolated from microaerobic sandy sediments of the floodplain area of the Boise River, Idaho, U.S.A., were studied using live observation, protargol impregnation, scanning electron microscopy, and the 18S rRNA gene as well as the ITS region. The Boise population of P. pupula is characterized by a size of about 60–130 × 20–50 μm, an elliptical macronucleus with a single micronucleus, highly refractive dumbbell-shaped inclusions scattered throughout the cytoplasm and concentrated in the anterior body half, a single subterminal/terminal contractile vacuole, about 10 μm long rod-shaped extrusomes, and an average of 15 ciliary rows. In phylogenetic analyses, the newly obtained sequences from P. pupula and Lacrymaria olor clustered within the family Lacrymariidae with full to moderate statistical support. Neither the genus Phialina nor the genus Lacrymaria was depicted monophyletic both in the single gene and multigene phylogenetic inferences. Specifically, the genus Phialina was shown as a paraphyletic assemblage containing members of the polyphyletic genus Lacrymaria. This indicates that the phialinid bauplan, i.e., an anterior body end differentiated into a head-like structure directly attached to the trunk, might represent the ground pattern in the family Lacrymariidae. On the other hand, the long highly contractile neck carrying the head-like structure probably evolved later and convergently in multiple Lacrymaria species from Phialina-like ancestors.
Volodymyr Yuryshynets, Markéta Ondračková, Yuriy Kvach, Gérard Masson
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 69-79
https://doi.org/10.4467/16890027AP.19.009.11418Three species of trichodinid ciliates, common parasites or symbionts of aquatic invertebrates and vertebrates, have been reported from pumpkinseed (Lepomis gibbosus, Centrarchidae) in both their native (Trichodina fultoni, T. tumefaciens) and introduced (T. fultoni, Trichodinella epizootica) ranges. In this study, we report five additional trichodinid taxa collected from invasive L. gibbosus in France and two regions of the Czech Republic. We describe a new species, Trichodina lepomi sp. n., recorded in L. gibbosus from both countries. The new species differs from T. nigra by absence of posterior projection of blade, absence of notch/ indentation opposing ray apophysis, absence of ray apophysis and the blade not being displaced anteriorly relative to ray as significantly as in T. nigra. Two widely distributed species, identified as Trichodina acuta and T. cf. heterodentata, were observed on juvenile fish in the Dyje river basin (Czech Republic). Finally, two undescribed species f Trichodina sp. and Tripartiella sp. are reported. Detailed description of the new species and comparison with other congeneric species are presented.
Felipe S. Coelho, Danielle P. Vieira, Angela H. Lopes, Maria A. Sousa
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 81-88
https://doi.org/10.4467/16890027AP.19.011.11420The protein profiles of the epimastigote stages from eight reference strains of Trypanosoma cruzi belonging to three different lineages (TcI, TcII and TcVI) were analyzed by SDS-PAGE (sodium dodecyl sulphate-polyacrylamide gel electrophoresis), under standardized conditions. More than 40 protein bands were observed in each strain. Around 55% of them were not shared by all stocks (non-conserved proteins), representing their intra-specific variability. Then, they were coded for processing by numerical taxonomy, using three association coefficients and the UPGMA clustering algorithm. With all coefficients assayed, two major groups were clearly seen, confirming the dichotomy within T. cruzi taxon, as demonstrated by other molecular and biochemical approaches. In the present study, the term peptideme was used to name the groups of strains based on their polypeptide profiles, following the above-cited methodology. Then, two major peptidemes were identified, each one presenting subdivisions. The isolates identified as TcI clustered in the same major peptideme, displaying a subgroup with the opossum isolates (G, SC28, Dm28c) apart from the stock of human origin (Colombian strain). The other major peptideme also showed two subgroups, regardless the coefficient used. One of them included the TcII strains (Y, SF21), both from Brazilian patients, and the other the TcVI stocks, both originally from triatomines from Southern Brazil (CL Brener, FL). As far we know, this is the first report on the parity between the T. cruzi lineages consensually accepted and their grouping into peptidemes based on SDS-PAGE and the numerical analysis of non-conserved proteins.
J. Antonio Heredia-Rojas, Abraham O. Rodríguez-De la Fuente, Ricardo Gomez-Flores, Merary Alvarez-Rodríguez, Zinnia J. Molina-Garza, M. Beltcheva, Omar Heredia-Rodríguez, Lucio Galaviz-Silva
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 89-92
https://doi.org/10.4467/16890027AP.19.008.11417The influence of extremely low-frequency electromagnetic fields (ELF-EMFs) on microorganisms has been a subject of experimental investigations with promising results. In the present study, it was demonstrated that 2.0 mT 60Hz ELF-EMFs inhibited Trypanosoma cruzi epimastigotes growth. In addition, no synergistic or antagonistic parasite growth and viability effects were observed after cultures were co-exposed to magnetic fields and Nifurtimox, a well-known anti-trypanosome drug. Moreover, the current study represents the first report regarding direct magnetic fields effects on Trypanosomas.
Kang-San Kim, Kyu-Seok Chae, Gi-Sik Min
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 43-51
https://doi.org/10.4467/16890027AP.19.005.10836A new marine urostylid ciliate, Arcuseries minima sp. nov., was discovered in South Korea. Morphological observations and molecular phylogenetic analyses based on small subunit ribosomal DNA (18S rDNA) sequences were used to describe the new species. Arcuseries minima is most similar to A. scutellum among all Arcuseries species, but differs in the following main characters: number of adoral membranelles (13–16 vs. 17 or 18), cortical granules (yellowish, clustered around cirri and dorsal bristles vs. colorless, irregularly scattered), number of macronuclear nodules (20–27 vs. 42–90), number of midventral cirri (5–10 vs. 12–14), and number f transverse cirri (5 or 6 vs. 8). The new species and A. scutellum differ from A. petzi and A. warreni in having smaller body size (≤80 μm vs. ≥80 μm) and fewer cirri: left marginal (≤ 17 vs. ≥ 18) and transverse (≤ 8 vs. ≥8) cirri. This relationship was supported by the phylogenetic tree, where these two groups were separated into two branches.
Ľubomír Rajter, William Bourland, Peter Vďačný
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 53-68
https://doi.org/10.4467/16890027AP.19.004.10835The morphology and phylogenetic position of a haptorian ciliate, Phialina pupula (Müller, 1773) Foissner, 1983, isolated from microaerobic sandy sediments of the floodplain area of the Boise River, Idaho, U.S.A., were studied using live observation, protargol impregnation, scanning electron microscopy, and the 18S rRNA gene as well as the ITS region. The Boise population of P. pupula is characterized by a size of about 60–130 × 20–50 μm, an elliptical macronucleus with a single micronucleus, highly refractive dumbbell-shaped inclusions scattered throughout the cytoplasm and concentrated in the anterior body half, a single subterminal/terminal contractile vacuole, about 10 μm long rod-shaped extrusomes, and an average of 15 ciliary rows. In phylogenetic analyses, the newly obtained sequences from P. pupula and Lacrymaria olor clustered within the family Lacrymariidae with full to moderate statistical support. Neither the genus Phialina nor the genus Lacrymaria was depicted monophyletic both in the single gene and multigene phylogenetic inferences. Specifically, the genus Phialina was shown as a paraphyletic assemblage containing members of the polyphyletic genus Lacrymaria. This indicates that the phialinid bauplan, i.e., an anterior body end differentiated into a head-like structure directly attached to the trunk, might represent the ground pattern in the family Lacrymariidae. On the other hand, the long highly contractile neck carrying the head-like structure probably evolved later and convergently in multiple Lacrymaria species from Phialina-like ancestors.
Volodymyr Yuryshynets, Markéta Ondračková, Yuriy Kvach, Gérard Masson
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 69-79
https://doi.org/10.4467/16890027AP.19.009.11418Three species of trichodinid ciliates, common parasites or symbionts of aquatic invertebrates and vertebrates, have been reported from pumpkinseed (Lepomis gibbosus, Centrarchidae) in both their native (Trichodina fultoni, T. tumefaciens) and introduced (T. fultoni, Trichodinella epizootica) ranges. In this study, we report five additional trichodinid taxa collected from invasive L. gibbosus in France and two regions of the Czech Republic. We describe a new species, Trichodina lepomi sp. n., recorded in L. gibbosus from both countries. The new species differs from T. nigra by absence of posterior projection of blade, absence of notch/ indentation opposing ray apophysis, absence of ray apophysis and the blade not being displaced anteriorly relative to ray as significantly as in T. nigra. Two widely distributed species, identified as Trichodina acuta and T. cf. heterodentata, were observed on juvenile fish in the Dyje river basin (Czech Republic). Finally, two undescribed species f Trichodina sp. and Tripartiella sp. are reported. Detailed description of the new species and comparison with other congeneric species are presented.
Felipe S. Coelho, Danielle P. Vieira, Angela H. Lopes, Maria A. Sousa
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 81-88
https://doi.org/10.4467/16890027AP.19.011.11420The protein profiles of the epimastigote stages from eight reference strains of Trypanosoma cruzi belonging to three different lineages (TcI, TcII and TcVI) were analyzed by SDS-PAGE (sodium dodecyl sulphate-polyacrylamide gel electrophoresis), under standardized conditions. More than 40 protein bands were observed in each strain. Around 55% of them were not shared by all stocks (non-conserved proteins), representing their intra-specific variability. Then, they were coded for processing by numerical taxonomy, using three association coefficients and the UPGMA clustering algorithm. With all coefficients assayed, two major groups were clearly seen, confirming the dichotomy within T. cruzi taxon, as demonstrated by other molecular and biochemical approaches. In the present study, the term peptideme was used to name the groups of strains based on their polypeptide profiles, following the above-cited methodology. Then, two major peptidemes were identified, each one presenting subdivisions. The isolates identified as TcI clustered in the same major peptideme, displaying a subgroup with the opossum isolates (G, SC28, Dm28c) apart from the stock of human origin (Colombian strain). The other major peptideme also showed two subgroups, regardless the coefficient used. One of them included the TcII strains (Y, SF21), both from Brazilian patients, and the other the TcVI stocks, both originally from triatomines from Southern Brazil (CL Brener, FL). As far we know, this is the first report on the parity between the T. cruzi lineages consensually accepted and their grouping into peptidemes based on SDS-PAGE and the numerical analysis of non-conserved proteins.
J. Antonio Heredia-Rojas, Abraham O. Rodríguez-De la Fuente, Ricardo Gomez-Flores, Merary Alvarez-Rodríguez, Zinnia J. Molina-Garza, M. Beltcheva, Omar Heredia-Rodríguez, Lucio Galaviz-Silva
Acta Protozoologica, Volume 58, Issue 2, 2019, pp. 89-92
https://doi.org/10.4467/16890027AP.19.008.11417The influence of extremely low-frequency electromagnetic fields (ELF-EMFs) on microorganisms has been a subject of experimental investigations with promising results. In the present study, it was demonstrated that 2.0 mT 60Hz ELF-EMFs inhibited Trypanosoma cruzi epimastigotes growth. In addition, no synergistic or antagonistic parasite growth and viability effects were observed after cultures were co-exposed to magnetic fields and Nifurtimox, a well-known anti-trypanosome drug. Moreover, the current study represents the first report regarding direct magnetic fields effects on Trypanosomas.
Publication date: 25.07.2019
Editor-in-Chief: Krzysztof Wiąckowski
Photo on the cover fromr: De Jager G. P., Basson L., Van Marwijk J. (2019) A New Trichodina Species (Peritrichia: Mobilida) from Anuran Tadpole Hosts, Sclerophrys spp. in the Okavango Panhandle, Botswana, with Comments on this Taxon. Acta Protozool. 58: 141-153.
Piotr Solarczyk, Natalia Osten-Sacken, Alain C. Frantz, Simone Schneider, Jacques B. Pir, Mike Heddergott
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 1-5
https://doi.org/10.4467/16890027AP.19.001.10832Giardia duodenalis is one of the most widespread intestinal parasites of humans and other vertebrates. In terms of public health, identification of Giardia assemblages in wildlife is important because only some assemblages of G. duodenalis can infect humans. Here, we use loop-mediated isothermal amplification (LAMP) and genotyping of analysis of the β-giardin gene to screen the zoonotic assemblages of G. duodenalis recovered from faeces of free-living European wildcats (Felis s. silvestris) from Luxembourg. Giardia DNA was detected in one animal (10%) and assigned to assemblage B by both methods. This is the first detection and genotyping of G. duodenalis in a European wild felid in general, and of assemblage B in particular. Free-living wildcats may act as reservoirs of G. duodenalis infectious for humans and other wildlife and domestic animals. Using a combination of LAMP- and genotyping-based methods allowed effective, sensitive, and rapid detection of a zoonotic G. duodenalis assemblage B in wildlife.
Elideth Pacheco Monteiro, Diehgo Tuloza Da Silva, Osimar Sanches, Igor Hamoy, Edilson Rodrigues Matos
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 7-16
https://doi.org/10.4467/16890027AP.19.002.10833A new species of myxozoan, Kudoa viseuensis n. sp. (Myxosporea: Multivalvulida), is described based on specimens extracted from the musculature of the Pacuma toadfish, Batrachoides surinamensis, collected in the municipality of Viseu, in the northern Brazilian state of Pará. A total of 60 specimens of B. surinamensis were examined, of which 52 (86%) presented whitish pseudocysts containing numerous rounded spores (7.2±0.2 μm in length and 5.2±0.2 μm in width). These spores have four polar capsules of equal size, measuring 1.8±0.2 μm x 1.3±0.1 μm in the apical view, and 2.7±0.2 μm x 1.3±0.1 μm in the lateral view. A partial sequence (1400 bps) of the small subunit ribosomal RNA gene was obtained and deposited in GenBank (access number: MK256272). The comparison of the morphological and molecular data with those of other Kudoa species supported the description of a new species of mixosporean from the Amazon region, which is denominated here as Kudoa viseuensis n. sp.
Jhon Lennon Genovez-Oliveira, Sergian V. Cardozo, Águida A. De Oliveira, Viviane M. De Lima, Ildemar Ferreira, Bruno P. Berto
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 17-23
https://doi.org/10.4467/16890027AP.19.007.10838Isospora sepetibensis Berto, Flausino, Luz, Ferreira and Lopes, 2008 is a protozoan coccidian parasite (Chromista: Miozoa: Coccidiomorphea: Coccidia) that was originally described from Brazilian tanagers Ramphocelus bresilius (Linnaeus, 1766) in the Marambaia Island in the Coast of the State of Rio de Janeiro. In the current work, this species was identified from black-goggled tanagers Trichothraupis melanops (Vieillot, 1818) in the Itatiaia National Park, which is a protected area with a high degree of vulnerability in the interior of the State of Rio de Janeiro, distant in more than 100 km of the type-locality. Its oocysts are sub-spherical to elongate ovoidal, 25.9 × 20.7 μm with smooth, bi-layered wall, ~ 1.3 μm and length/width ratio of 1.1–1.4 (1.26). Micropyle and oocyst residuum absent, but one or two polar granules are present. Sporocysts are ellipsoidal, 16.8 × 10.3 μm, with both Stieda and sub-Stieda bodies. Sporocyst residuum present and sporozoites with refractile body and nucleus. Molecular analysis was conducted at the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. This new isolate exhibited similarity greater than 98% with Isospora spp. isolates from other Neotropical passerines and with an Isospora sp. pseudoparasite of voles of Eurasia. This is the first coccidian parasite from a New World tanager to have a molecular identification of the cox1 gene.
Yoichiro Sogame, Ryota Saito, Ryota Koizumi, Taiga Shimizu, Taiki Ono
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 25-29
https://doi.org/10.4467/16890027AP.19.006.10837In this study, we report that the unicellular free-living protist Colpoda cucullus in the resting cyst (cryptobiosis) repairs stress damage. We previously demonstrated that resting cysts of Colpoda cucullus have extreme tolerance to gamma irradiation and can revert to vegetative cells after irradiation. Such irradiated cysts gradually excyst, suggesting that stress repair mechanisms are active during excystment or in the resting cyst. Herein we provide bioassay evidence that the rate of excystment of irradiated cysts is elevated by subsequent incubation, thereby indicating that cells injured by gamma irradiation can repair themselves in the resting cyst, whereas irradiated dry cysts cannot.
J. Mercy Nisha Pauline, Anant Achary
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 31-41
https://doi.org/10.4467/16890027AP.19.003.10834The algal medium was optimized to increase the biomass and lipid production of Chlorococcum oleofaciens. The significant variables were screened and chosen from previously reported algal culture media using Plackett Burman Design (PBD). Optimization of the significant variables were performed using central composite design. The Pareto chart for PBD revealed that the salts such as sodium bicarbonate, sodium nitrate, potassium nitrate and ferrous sulphate had enhanced the biomass and lipid production. The variables and its effect on the responses were further studied by central composite design (CCD). A new medium was formulated based on the response surface methodology. The predicted concentration of NaHCO3, NaNO3, KNO3, MgSO4.7H2O were found to be 6.75 g/L, 0.75 g/L, 1.88 g/L and 0.35 g/L respectively. The actual and the predicted total lipid yield for the optimized media was around 0.74 g/L and 0.78 g/L respectively. The optimal medium has been named as AM medium. Growth and the lipid yields of C. oleofaciens were found higher in AM medium. The specific growth rates of C. oleofaciens in AM and CFTRI media were found to be 0.14 day-1 and 0.19 day-1 respectively. The biomass produced by the optimized AM medium was found to be 2.7 times greater compared to the CFTRI medium. The lipid was extracted and GC-MS was performed which revealed that the fatty acids were predominantly of the class C15:0, C18:0, C16:0 and C12:0. It is concluded that besides lipid content, AM medium increased the cell number leading to the increase in biomass.
Piotr Solarczyk, Natalia Osten-Sacken, Alain C. Frantz, Simone Schneider, Jacques B. Pir, Mike Heddergott
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 1-5
https://doi.org/10.4467/16890027AP.19.001.10832Giardia duodenalis is one of the most widespread intestinal parasites of humans and other vertebrates. In terms of public health, identification of Giardia assemblages in wildlife is important because only some assemblages of G. duodenalis can infect humans. Here, we use loop-mediated isothermal amplification (LAMP) and genotyping of analysis of the β-giardin gene to screen the zoonotic assemblages of G. duodenalis recovered from faeces of free-living European wildcats (Felis s. silvestris) from Luxembourg. Giardia DNA was detected in one animal (10%) and assigned to assemblage B by both methods. This is the first detection and genotyping of G. duodenalis in a European wild felid in general, and of assemblage B in particular. Free-living wildcats may act as reservoirs of G. duodenalis infectious for humans and other wildlife and domestic animals. Using a combination of LAMP- and genotyping-based methods allowed effective, sensitive, and rapid detection of a zoonotic G. duodenalis assemblage B in wildlife.
Elideth Pacheco Monteiro, Diehgo Tuloza Da Silva, Osimar Sanches, Igor Hamoy, Edilson Rodrigues Matos
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 7-16
https://doi.org/10.4467/16890027AP.19.002.10833A new species of myxozoan, Kudoa viseuensis n. sp. (Myxosporea: Multivalvulida), is described based on specimens extracted from the musculature of the Pacuma toadfish, Batrachoides surinamensis, collected in the municipality of Viseu, in the northern Brazilian state of Pará. A total of 60 specimens of B. surinamensis were examined, of which 52 (86%) presented whitish pseudocysts containing numerous rounded spores (7.2±0.2 μm in length and 5.2±0.2 μm in width). These spores have four polar capsules of equal size, measuring 1.8±0.2 μm x 1.3±0.1 μm in the apical view, and 2.7±0.2 μm x 1.3±0.1 μm in the lateral view. A partial sequence (1400 bps) of the small subunit ribosomal RNA gene was obtained and deposited in GenBank (access number: MK256272). The comparison of the morphological and molecular data with those of other Kudoa species supported the description of a new species of mixosporean from the Amazon region, which is denominated here as Kudoa viseuensis n. sp.
Jhon Lennon Genovez-Oliveira, Sergian V. Cardozo, Águida A. De Oliveira, Viviane M. De Lima, Ildemar Ferreira, Bruno P. Berto
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 17-23
https://doi.org/10.4467/16890027AP.19.007.10838Isospora sepetibensis Berto, Flausino, Luz, Ferreira and Lopes, 2008 is a protozoan coccidian parasite (Chromista: Miozoa: Coccidiomorphea: Coccidia) that was originally described from Brazilian tanagers Ramphocelus bresilius (Linnaeus, 1766) in the Marambaia Island in the Coast of the State of Rio de Janeiro. In the current work, this species was identified from black-goggled tanagers Trichothraupis melanops (Vieillot, 1818) in the Itatiaia National Park, which is a protected area with a high degree of vulnerability in the interior of the State of Rio de Janeiro, distant in more than 100 km of the type-locality. Its oocysts are sub-spherical to elongate ovoidal, 25.9 × 20.7 μm with smooth, bi-layered wall, ~ 1.3 μm and length/width ratio of 1.1–1.4 (1.26). Micropyle and oocyst residuum absent, but one or two polar granules are present. Sporocysts are ellipsoidal, 16.8 × 10.3 μm, with both Stieda and sub-Stieda bodies. Sporocyst residuum present and sporozoites with refractile body and nucleus. Molecular analysis was conducted at the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene. This new isolate exhibited similarity greater than 98% with Isospora spp. isolates from other Neotropical passerines and with an Isospora sp. pseudoparasite of voles of Eurasia. This is the first coccidian parasite from a New World tanager to have a molecular identification of the cox1 gene.
Yoichiro Sogame, Ryota Saito, Ryota Koizumi, Taiga Shimizu, Taiki Ono
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 25-29
https://doi.org/10.4467/16890027AP.19.006.10837In this study, we report that the unicellular free-living protist Colpoda cucullus in the resting cyst (cryptobiosis) repairs stress damage. We previously demonstrated that resting cysts of Colpoda cucullus have extreme tolerance to gamma irradiation and can revert to vegetative cells after irradiation. Such irradiated cysts gradually excyst, suggesting that stress repair mechanisms are active during excystment or in the resting cyst. Herein we provide bioassay evidence that the rate of excystment of irradiated cysts is elevated by subsequent incubation, thereby indicating that cells injured by gamma irradiation can repair themselves in the resting cyst, whereas irradiated dry cysts cannot.
J. Mercy Nisha Pauline, Anant Achary
Acta Protozoologica, Volume 58, Issue 1, 2019, pp. 31-41
https://doi.org/10.4467/16890027AP.19.003.10834The algal medium was optimized to increase the biomass and lipid production of Chlorococcum oleofaciens. The significant variables were screened and chosen from previously reported algal culture media using Plackett Burman Design (PBD). Optimization of the significant variables were performed using central composite design. The Pareto chart for PBD revealed that the salts such as sodium bicarbonate, sodium nitrate, potassium nitrate and ferrous sulphate had enhanced the biomass and lipid production. The variables and its effect on the responses were further studied by central composite design (CCD). A new medium was formulated based on the response surface methodology. The predicted concentration of NaHCO3, NaNO3, KNO3, MgSO4.7H2O were found to be 6.75 g/L, 0.75 g/L, 1.88 g/L and 0.35 g/L respectively. The actual and the predicted total lipid yield for the optimized media was around 0.74 g/L and 0.78 g/L respectively. The optimal medium has been named as AM medium. Growth and the lipid yields of C. oleofaciens were found higher in AM medium. The specific growth rates of C. oleofaciens in AM and CFTRI media were found to be 0.14 day-1 and 0.19 day-1 respectively. The biomass produced by the optimized AM medium was found to be 2.7 times greater compared to the CFTRI medium. The lipid was extracted and GC-MS was performed which revealed that the fatty acids were predominantly of the class C15:0, C18:0, C16:0 and C12:0. It is concluded that besides lipid content, AM medium increased the cell number leading to the increase in biomass.
Publication date: 12.02.2019
Editor-in-Chief: Krzysztof Wiąckowski
Hoan Q. Trana, Yuri A. Mazei
Acta Protozoologica, Volume 57, Issue 4, 2018, pp. 215-229
https://doi.org/10.4467/16890027AP.18.016.10092Testate amoebae in Vietnam are still poorly investigated. We studied species composition of testate amoebae in 47 waterbodies of South Vietnam provinces including natural lakes, reservoirs, wetlands, rivers, and irrigation channels. A total of 109 species and subspecies belonging to 16 genera, 9 families were identified from 191 samples. Thirty-five species and subspecies were observed in Vietnam for the first time. New species Difflugia vietnamica sp. nov. is described. The most species-rich genera are Difflugia (46 taxa), Arcella (25) and Centropyxis (14). Centropyxis aculeata was the most common species (observed in 68.1% samples). Centropyxis aerophila sphagniсola, Arcella discoides, Difflugia schurmanni and Lesquereusia modesta were characterised by a frequency of occurrence >20%. Other species were rarer. The species accumulation curve based on the entire dataset of this work was unsaturated and well fitted by equation S = 19.46N0.33. Species richness per sample in natural lakes and wetlands were significantly higher than that of rivers (p < 0.001). The result of the Spearman rank test shows weak or statistically insignificant relationships between species richness and water temperature, pH, dissolved oxygen, and electrical conductivity.
Horacio Pérez-Juárez, Angélica Serrano-Vázquez, Enrique Lara, Cecilia Ximénez, Héctor Godínez-Alvarez, Salvador Rodríguez-Zaragoza, Luis E. Eguiarte, Mayra M. Hernández Moreno, Leonardo David Fernández, Leonardo D. Fernández , Liliana Rojas-Velázquez, Patricia Morán, Mariela Castillo, Víctor M. Rivera Aguilar
Acta Protozoologica, Volume 57, Issue 4, 2018, pp. 231-242
https://doi.org/10.4467/16890027AP.18.017.10093In arid environments, protist diversity is higher in soil covered by vegetation than in bare soil and is also likely to vary in line with the marked seasonal patterns; however, these patterns have not been explored in detail in arid zones. Herein, we used culture – and morphological-based approaches to describe patterns of amoeboid protist diversity in vegetated and bare soil areas from the intertropical desert of Tehuacán, Mexico, during dry and wet seasons. Overall, 27 protist species belonging to Amoebozoa, Discoba and Rhizaria were retrieved using culture-dependent methods. Among the soil protist groups found, Discoba (principally represented by Heterolobosea) was always the most prevalent taxa. Protist diversity was different between soil with vegetation and bare soil, principally during the dry season. Moreover, the electrical conductivity and pH of the soil were correlated with the protist species during the wet season. Our results support the hypothesis that soil protist diversity patterns exhibit a seasonal variation between dry and wet seasons. This seasonal variation likely relies on water availability, although the role of other environmental factors cannot be completely ruled out. In addition, the soils with vegetation could be a refuge for the amoeboid protists during the harsh soil conditions of dry seasons.
Kristina I. Prokina, Dmitry G. Zagumyonnyi, Denis V. Tikhonenkov
Acta Protozoologica, Volume 57, Issue 4, 2018, pp. 245-266
https://doi.org/10.4467/16890027AP.18.018.10094Species diversity of centrohelid heliozoans in different types of freshwater bodies (forest lakes, floodplain lakes, sphagnum bogs, and river) in the Middle Russian forest-steppe was studied. The morphology of cell coverings (scales and spicules) were observed using scanning and transmission electron microscopy. A total of 20 species of centrohelid heliozoans from five families (Acanthocystidae, Pterocystidae, Raphidiophryidae, Raphidocystidae, and Choanocystidae) and six genera (Acanthocystis, Raineriophrys, Pterocystis, Raphidiophrys, Raphidocystis, and Choanocystis) as well as unidentified Centrohelea species and a Heterophrys-like organism were found. Morphological descriptions and electron micrographs are provided. The most common species were Acanthocystis nichollsi, Raphidiophrys capitata, and a Heterophrys-like organism. The highest species diversity was observed in terrace forest lakes, whereas the lowest was seen in sphagnum bogs. Four species (Acanthocystis costata, A. elenazhivotovae, A. mikrjukovii, and A. spinosa) were found for the first time since their original description. Three species (Acanthocystis spinosa, Raphidiophrys capitata, and Pterocystis pulchra) are new records for Russia. The distribution of the observed morphospecies confirms the cosmopolitanism of many centrohelids and highlights the importance of the type of water body and microbiotope in forming the species composition. The obtained data on the morphology of studied scales supplements our knowledge of the intraspecific variability of centrohelid heliozoans.
Hoan Q. Trana, Yuri A. Mazei
Acta Protozoologica, Volume 57, Issue 4, 2018, pp. 215-229
https://doi.org/10.4467/16890027AP.18.016.10092Testate amoebae in Vietnam are still poorly investigated. We studied species composition of testate amoebae in 47 waterbodies of South Vietnam provinces including natural lakes, reservoirs, wetlands, rivers, and irrigation channels. A total of 109 species and subspecies belonging to 16 genera, 9 families were identified from 191 samples. Thirty-five species and subspecies were observed in Vietnam for the first time. New species Difflugia vietnamica sp. nov. is described. The most species-rich genera are Difflugia (46 taxa), Arcella (25) and Centropyxis (14). Centropyxis aculeata was the most common species (observed in 68.1% samples). Centropyxis aerophila sphagniсola, Arcella discoides, Difflugia schurmanni and Lesquereusia modesta were characterised by a frequency of occurrence >20%. Other species were rarer. The species accumulation curve based on the entire dataset of this work was unsaturated and well fitted by equation S = 19.46N0.33. Species richness per sample in natural lakes and wetlands were significantly higher than that of rivers (p < 0.001). The result of the Spearman rank test shows weak or statistically insignificant relationships between species richness and water temperature, pH, dissolved oxygen, and electrical conductivity.
Horacio Pérez-Juárez, Angélica Serrano-Vázquez, Enrique Lara, Cecilia Ximénez, Héctor Godínez-Alvarez, Salvador Rodríguez-Zaragoza, Luis E. Eguiarte, Mayra M. Hernández Moreno, Leonardo David Fernández, Leonardo D. Fernández , Liliana Rojas-Velázquez, Patricia Morán, Mariela Castillo, Víctor M. Rivera Aguilar
Acta Protozoologica, Volume 57, Issue 4, 2018, pp. 231-242
https://doi.org/10.4467/16890027AP.18.017.10093In arid environments, protist diversity is higher in soil covered by vegetation than in bare soil and is also likely to vary in line with the marked seasonal patterns; however, these patterns have not been explored in detail in arid zones. Herein, we used culture – and morphological-based approaches to describe patterns of amoeboid protist diversity in vegetated and bare soil areas from the intertropical desert of Tehuacán, Mexico, during dry and wet seasons. Overall, 27 protist species belonging to Amoebozoa, Discoba and Rhizaria were retrieved using culture-dependent methods. Among the soil protist groups found, Discoba (principally represented by Heterolobosea) was always the most prevalent taxa. Protist diversity was different between soil with vegetation and bare soil, principally during the dry season. Moreover, the electrical conductivity and pH of the soil were correlated with the protist species during the wet season. Our results support the hypothesis that soil protist diversity patterns exhibit a seasonal variation between dry and wet seasons. This seasonal variation likely relies on water availability, although the role of other environmental factors cannot be completely ruled out. In addition, the soils with vegetation could be a refuge for the amoeboid protists during the harsh soil conditions of dry seasons.
Kristina I. Prokina, Dmitry G. Zagumyonnyi, Denis V. Tikhonenkov
Acta Protozoologica, Volume 57, Issue 4, 2018, pp. 245-266
https://doi.org/10.4467/16890027AP.18.018.10094Species diversity of centrohelid heliozoans in different types of freshwater bodies (forest lakes, floodplain lakes, sphagnum bogs, and river) in the Middle Russian forest-steppe was studied. The morphology of cell coverings (scales and spicules) were observed using scanning and transmission electron microscopy. A total of 20 species of centrohelid heliozoans from five families (Acanthocystidae, Pterocystidae, Raphidiophryidae, Raphidocystidae, and Choanocystidae) and six genera (Acanthocystis, Raineriophrys, Pterocystis, Raphidiophrys, Raphidocystis, and Choanocystis) as well as unidentified Centrohelea species and a Heterophrys-like organism were found. Morphological descriptions and electron micrographs are provided. The most common species were Acanthocystis nichollsi, Raphidiophrys capitata, and a Heterophrys-like organism. The highest species diversity was observed in terrace forest lakes, whereas the lowest was seen in sphagnum bogs. Four species (Acanthocystis costata, A. elenazhivotovae, A. mikrjukovii, and A. spinosa) were found for the first time since their original description. Three species (Acanthocystis spinosa, Raphidiophrys capitata, and Pterocystis pulchra) are new records for Russia. The distribution of the observed morphospecies confirms the cosmopolitanism of many centrohelids and highlights the importance of the type of water body and microbiotope in forming the species composition. The obtained data on the morphology of studied scales supplements our knowledge of the intraspecific variability of centrohelid heliozoans.
Publication date: 11.01.2019
Editor-in-Chief: Krzysztof Wiąckowski
Wen Song, Jiamei Li, Yaoyao Huang, Xiaozhong Hu, Weiwei Liu, Khaled A. S. Al-Rasheid, Miao Miao
Acta Protozoologica, Volume 57, Issue 3, 2018, pp. 153-167
https://doi.org/10.4467/16890027AP.18.013.10089As a follow-up part of our studies of the tropical ciliate fauna carried out in the last decade, we investigated the morphology and phylogeny of three choreotrich ciliates, viz, Parastrombidinopsis costalis sp. n., P. pelagica (Fauré-Fremiet, 1924) comb. n. and P. minima Tsai et al., 2008. The new species is characterized by its unique asymmetrical cell shape, 19–21 collar membranelles, one buccal membrane, and eight unevenly distributed somatic kineties.An improved diagnosis of P. pelagica(Fauré-Fremiet, 1924) comb. n.is given based on the original and current studies, the species is characterized by a large cell size, an elongate obconical cell shape, 31–36 collar membranelles and 13–15 somatic kineties. The species P. minimais redescribed based on a new population with some new features supplemented.SSU rRNA genes of both the new species and P. minima were sequenced and a phylogenetic review of related taxa obtained has been performed in order to reveal their systematic relationships. The monophyly of the genus Parastrombidinopsis is highly supported in our phylogenetic analyses.
Christian F. Bardele, Nicole Stockmann, Sabine Agatha
Acta Protozoologica, Volume 57, Issue 3, 2018, pp. 169-193
https://doi.org/10.4467/16890027AP.18.014.10090The first transmission and scanning electron microscopical studies in combination with freeze-fracture technology have disclosed some important morphological and ultrastructural features in the freshwater oligotrichid Limnostrombidium viride. (I) The dikinetids (paired basal bodies) of the girdle kinety have a club-shaped cilium associated only with each left basal body. The electron-dense (paraflagellar) body on one side of its “92+2”-axoneme and the regular array of intramembranous particles indicate a sensory, perhaps photoreceptor function of these club-shaped cilia. (II) The stichomonad endoral membrane is proximally covered by a cytoplasmic fold and distally by multiple membranous layers. Thus entirely covered, the endoral is probably no longer involved in food capture; none the less, its associated microtubules might stabilise the cytopharynx. (III) Instead of a contractile vacuole, a horizontal ring-canal with supposed osmoregulatory function occurs. (IV) The extrusive nature of the trichites is not only observed in electron micrographs, but the attachment sites of these organelles also display a rosette of “8+1”-particles in the P-face of freeze-fracture replicas typical for ciliate extrusomes. (V) The neoformation organelle, the subsurface tube in which stomatogenesis takes place, shows short basal bodies and normal axonemes about 1 μm long. It is accompanied by numerous membrane vesicles, which might provide membrane material for the outgrowing cilia.
Michael S. Gruber, Alexandra Mühlthaler, Sabine Agatha
Acta Protozoologica, Volume 57, Issue 3, 2018, pp. 195-214
https://doi.org/10.4467/16890027AP.18.015.10091Molecular phylogenies of Oligotrichea currently do not contain all genera and families and display topologies which are often incongruent with morphological findings. In ciliates, the somatic kinetids are rather conserved, i.e., their ultrastructures, particularly the fibrillar associates, often characterise the main groups, except for the choreotrichids. Four different kinetid types are found in protargolstained choreotrichids and used for reconstructing the taxon’s evolution (the “Kinetid Transformation Hypothesis”). Proof for this hypothesis requires transmission electron microscopic studies, which are very rare in the choreotrichids and oligotrichids. Such an approach provides insights into the ultrastructural variability of somatic kinetids in spirotrichs and may also detect apomorphies characterising certain choreotrichid families. In the model tintinnid Schmidingerella meunieri, the ultrastructure of the three kinetid types in the somatic ciliature is studied in cryofixed cells. The data support the “Kinetid Transformation Hypothesis” regarding tintinnids with a ventral kinety. This first detailed study on kinetids in tintinnids and choreotrichids in general reveals totally new kinetid types in ciliates: beyond the three common associates, they are characterised by two or three conspicuous microtubular ribbons extending on the kinetids’ left sides. These extraordinary ribbons form together with the overlapping postciliary ribbons a unique network in the cortex of the anterior cell portion. The evolutionary constrains which might have fostered the development of such structures are discussed for the Oligotrichea, the choreotrichids, and tintinnids as their first occurrence is currently uncertain. Additionally, the kinetids in tintinnids, aloricate choreotrichids, oligotrichids, hypotrichs, and euplotids are compared.
Wen Song, Jiamei Li, Yaoyao Huang, Xiaozhong Hu, Weiwei Liu, Khaled A. S. Al-Rasheid, Miao Miao
Acta Protozoologica, Volume 57, Issue 3, 2018, pp. 153-167
https://doi.org/10.4467/16890027AP.18.013.10089As a follow-up part of our studies of the tropical ciliate fauna carried out in the last decade, we investigated the morphology and phylogeny of three choreotrich ciliates, viz, Parastrombidinopsis costalis sp. n., P. pelagica (Fauré-Fremiet, 1924) comb. n. and P. minima Tsai et al., 2008. The new species is characterized by its unique asymmetrical cell shape, 19–21 collar membranelles, one buccal membrane, and eight unevenly distributed somatic kineties.An improved diagnosis of P. pelagica(Fauré-Fremiet, 1924) comb. n.is given based on the original and current studies, the species is characterized by a large cell size, an elongate obconical cell shape, 31–36 collar membranelles and 13–15 somatic kineties. The species P. minimais redescribed based on a new population with some new features supplemented.SSU rRNA genes of both the new species and P. minima were sequenced and a phylogenetic review of related taxa obtained has been performed in order to reveal their systematic relationships. The monophyly of the genus Parastrombidinopsis is highly supported in our phylogenetic analyses.
Christian F. Bardele, Nicole Stockmann, Sabine Agatha
Acta Protozoologica, Volume 57, Issue 3, 2018, pp. 169-193
https://doi.org/10.4467/16890027AP.18.014.10090The first transmission and scanning electron microscopical studies in combination with freeze-fracture technology have disclosed some important morphological and ultrastructural features in the freshwater oligotrichid Limnostrombidium viride. (I) The dikinetids (paired basal bodies) of the girdle kinety have a club-shaped cilium associated only with each left basal body. The electron-dense (paraflagellar) body on one side of its “92+2”-axoneme and the regular array of intramembranous particles indicate a sensory, perhaps photoreceptor function of these club-shaped cilia. (II) The stichomonad endoral membrane is proximally covered by a cytoplasmic fold and distally by multiple membranous layers. Thus entirely covered, the endoral is probably no longer involved in food capture; none the less, its associated microtubules might stabilise the cytopharynx. (III) Instead of a contractile vacuole, a horizontal ring-canal with supposed osmoregulatory function occurs. (IV) The extrusive nature of the trichites is not only observed in electron micrographs, but the attachment sites of these organelles also display a rosette of “8+1”-particles in the P-face of freeze-fracture replicas typical for ciliate extrusomes. (V) The neoformation organelle, the subsurface tube in which stomatogenesis takes place, shows short basal bodies and normal axonemes about 1 μm long. It is accompanied by numerous membrane vesicles, which might provide membrane material for the outgrowing cilia.
Michael S. Gruber, Alexandra Mühlthaler, Sabine Agatha
Acta Protozoologica, Volume 57, Issue 3, 2018, pp. 195-214
https://doi.org/10.4467/16890027AP.18.015.10091Molecular phylogenies of Oligotrichea currently do not contain all genera and families and display topologies which are often incongruent with morphological findings. In ciliates, the somatic kinetids are rather conserved, i.e., their ultrastructures, particularly the fibrillar associates, often characterise the main groups, except for the choreotrichids. Four different kinetid types are found in protargolstained choreotrichids and used for reconstructing the taxon’s evolution (the “Kinetid Transformation Hypothesis”). Proof for this hypothesis requires transmission electron microscopic studies, which are very rare in the choreotrichids and oligotrichids. Such an approach provides insights into the ultrastructural variability of somatic kinetids in spirotrichs and may also detect apomorphies characterising certain choreotrichid families. In the model tintinnid Schmidingerella meunieri, the ultrastructure of the three kinetid types in the somatic ciliature is studied in cryofixed cells. The data support the “Kinetid Transformation Hypothesis” regarding tintinnids with a ventral kinety. This first detailed study on kinetids in tintinnids and choreotrichids in general reveals totally new kinetid types in ciliates: beyond the three common associates, they are characterised by two or three conspicuous microtubular ribbons extending on the kinetids’ left sides. These extraordinary ribbons form together with the overlapping postciliary ribbons a unique network in the cortex of the anterior cell portion. The evolutionary constrains which might have fostered the development of such structures are discussed for the Oligotrichea, the choreotrichids, and tintinnids as their first occurrence is currently uncertain. Additionally, the kinetids in tintinnids, aloricate choreotrichids, oligotrichids, hypotrichs, and euplotids are compared.
Publication date: 06.06.2018
Editor-in-Chief: Krzysztof Wiąckowski
Yufan Deng, Xiaoteng Lu, Jingbao Li, Sang Ba, Thiago da Silva Paiva
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 69-78
https://doi.org/10.4467/16890027AP.18.007.8981In this study, morphology of a Brazilian population of Eschaneustyla terricola Foissner, 1982 and a Chinese population of E. lugeri Foissner, Agatha & Berger, 2002 were studied based on living observation and protargol impregnation. Several stages of morphogenesis in E. lugeri were reported and the most remarkable features are characterized as follows: (1) partly renewal of adoral zone of membranelles in the proter and the parental midventral cirri do not join the construction of the opisthe’s oral primordium; (2) three or four buccal cirri each develop from one frontoventral cirral anlage and undulating membranes anlage generates two frontal cirri; (3) frontoventral cirral anlagen n and n-1 develop de novo and in the frontoterminal cirral row, respectively; (4) intrakinetal development of marginal and dorsal kineties anlagen; (5) fusion of macronuclear nodules into a single mass.
Yang Bai, Song Li, Yuan Li, Miao Miao, Xiaozhong Hu
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 79-94
https://doi.org/10.4467/16890027AP.18.008.8982A Chinese population of Oxytricha nauplia Berger et Foissner, 1987 was recently discovered from the surface soil in the Kuisu Valley, Huhhot, China. Its morphology corresponds well with that of the original population in the body size and shape, the absence of cortical granules, two macronuclear nodules and two micronuclei. Both morphogenesis during binary fission and small subunit of ribosomal gene (SSU rDNA) of the species were first investigated. Though earlier dividers are unavailable for this species, morphogenesis almost proceeds as in congeners by given stages. The SSU rDNA sequence of O. nauplia is 1728 bp long and has a DNA G+C content of 45.72%. Phylogenetic analyses revealed that Oxytricha nauplia grouped with O. paragranulifera first with high support, and then clustered into a subclade including Onychodromopsis flexilis, Paroxytricha ottowi, Paroxytricha longigranulosa and Rigidothrix goiseri, which branched off most congeners, but clustered into the Oxytrichidae clade.
Zhishuai Qu, René Groben, Viggó Marteinsson, Sabine Agatha, Sabine Filker, Thorsten Stoeck
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 95-106
https://doi.org/10.4467/16890027AP.18.009.8983We isolated an encysted ciliate from a geothermal field in Iceland. The morphological features of this isolate fit the descriptions of Dexiotricha colpidiopsis (Kahl, 1926) Jankowski, 1964 very well. These comprise body shape and size in vivo, the number of somatic kineties, and the positions of macronucleus and contractile vacuole. Using state-of-the-art taxonomic methods, the species is redescribed, including phylogenetic analyses of the small subunit ribosomal RNA (SSU rRNA) gene as molecular marker. In the phylogenetic analyses, D. colpidiopsis clusters with the three available SSU rRNA gene sequences of congeners, suggesting a monophyly of the genus Dexiotricha. Its closest relative in phylogenetic analyses is D. elliptica, which also shows a high morphological similarity. This is the first record of a Dexiotricha species from a hot spring, indicating a wide temperature tolerance of this species at least in the encysted state. The new findings on D. colpidiopsis are included in a briefly revision of the scuticociliate genus Dexiotricha and an identification key to the species.
Yingzhi Ning, Yongqiang Yang, Tengteng Zhang, Lingyun Chen, Khaled A. S. Al-Rasheid, Zhenzhen Yi
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 107-122
https://doi.org/10.4467/16890027AP.18.010.8984The morphology and morphogenesis of two populations of the soil hypotrichous ciliate, Parakahliella macrostoma (Foissner, 1982) Berger et al. 1985, isolated from northwest China, were investigated based on specimens examined in vivo and stained with protargol. Our populations resemble the original one in terms of their live characters and cirral pattern. The main events during binary fission are as follows: (1) the parental adoral zone of membranelles is retained completely by the proter; (2) both in the proter and in the opisthe five frontal-ventral cirral anlagen are recognizable; (3) the marginal rows and dorsal kineties develop intrakinetally. In addition, the SSU rRNA gene was sequenced for the genus Parakahliella for the first time. Molecular phylogenetic analyses suggest that two populations of the genus Parakahliella cluster together and have a close relationship with species of Oxytrichidae.
Borong Lu, Daode Ji, Yalan Sheng, Weibo Song, Xiaozhong Hu, Xiangrui Chen, Khaled A. S. Al-Rasheid
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 123-143
https://doi.org/10.4467/16890027AP.18.011.8985Alma G. Islas-Ortega, Rogelio Aguilar-Aguilar, Paula S. Marcotegui , Sergio R. Martorelli, David Hernández-Mena, Gerardo Pérez-Ponce de León
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 145-151
https://doi.org/10.4467/16890027AP.18.012.8986Trichodina rectuncinata is one of the trichodinids most widely distributed in marine fish. This ciliate species has been recorded in more than 20 host species belonging to 17 fish families worldwide. Previous comparative studies based on morphometric data revealed considerable morphological variation among specimens from different populations of T. rectuncinata. In this study, we conducted a morphometric-molecular analysis of three populations of T. rectuncinata to evaluate potential differences among 18S rRNA sequences, in relation to morphological variations. Smears were obtained from marine fishes in three localities along the Pacific coast of Mexico. Based on the shape of denticles, we found four different morphotypes for T. rectuncinata. This morphological variability does not correspond with the genetic divergence, suggesting that all analyzed populations belong to the same species. Further analyses using more variable markers are necessary to corroborate the findings of our study.
Yufan Deng, Xiaoteng Lu, Jingbao Li, Sang Ba, Thiago da Silva Paiva
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 69-78
https://doi.org/10.4467/16890027AP.18.007.8981In this study, morphology of a Brazilian population of Eschaneustyla terricola Foissner, 1982 and a Chinese population of E. lugeri Foissner, Agatha & Berger, 2002 were studied based on living observation and protargol impregnation. Several stages of morphogenesis in E. lugeri were reported and the most remarkable features are characterized as follows: (1) partly renewal of adoral zone of membranelles in the proter and the parental midventral cirri do not join the construction of the opisthe’s oral primordium; (2) three or four buccal cirri each develop from one frontoventral cirral anlage and undulating membranes anlage generates two frontal cirri; (3) frontoventral cirral anlagen n and n-1 develop de novo and in the frontoterminal cirral row, respectively; (4) intrakinetal development of marginal and dorsal kineties anlagen; (5) fusion of macronuclear nodules into a single mass.
Yang Bai, Song Li, Yuan Li, Miao Miao, Xiaozhong Hu
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 79-94
https://doi.org/10.4467/16890027AP.18.008.8982A Chinese population of Oxytricha nauplia Berger et Foissner, 1987 was recently discovered from the surface soil in the Kuisu Valley, Huhhot, China. Its morphology corresponds well with that of the original population in the body size and shape, the absence of cortical granules, two macronuclear nodules and two micronuclei. Both morphogenesis during binary fission and small subunit of ribosomal gene (SSU rDNA) of the species were first investigated. Though earlier dividers are unavailable for this species, morphogenesis almost proceeds as in congeners by given stages. The SSU rDNA sequence of O. nauplia is 1728 bp long and has a DNA G+C content of 45.72%. Phylogenetic analyses revealed that Oxytricha nauplia grouped with O. paragranulifera first with high support, and then clustered into a subclade including Onychodromopsis flexilis, Paroxytricha ottowi, Paroxytricha longigranulosa and Rigidothrix goiseri, which branched off most congeners, but clustered into the Oxytrichidae clade.
Zhishuai Qu, René Groben, Viggó Marteinsson, Sabine Agatha, Sabine Filker, Thorsten Stoeck
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 95-106
https://doi.org/10.4467/16890027AP.18.009.8983We isolated an encysted ciliate from a geothermal field in Iceland. The morphological features of this isolate fit the descriptions of Dexiotricha colpidiopsis (Kahl, 1926) Jankowski, 1964 very well. These comprise body shape and size in vivo, the number of somatic kineties, and the positions of macronucleus and contractile vacuole. Using state-of-the-art taxonomic methods, the species is redescribed, including phylogenetic analyses of the small subunit ribosomal RNA (SSU rRNA) gene as molecular marker. In the phylogenetic analyses, D. colpidiopsis clusters with the three available SSU rRNA gene sequences of congeners, suggesting a monophyly of the genus Dexiotricha. Its closest relative in phylogenetic analyses is D. elliptica, which also shows a high morphological similarity. This is the first record of a Dexiotricha species from a hot spring, indicating a wide temperature tolerance of this species at least in the encysted state. The new findings on D. colpidiopsis are included in a briefly revision of the scuticociliate genus Dexiotricha and an identification key to the species.
Yingzhi Ning, Yongqiang Yang, Tengteng Zhang, Lingyun Chen, Khaled A. S. Al-Rasheid, Zhenzhen Yi
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 107-122
https://doi.org/10.4467/16890027AP.18.010.8984The morphology and morphogenesis of two populations of the soil hypotrichous ciliate, Parakahliella macrostoma (Foissner, 1982) Berger et al. 1985, isolated from northwest China, were investigated based on specimens examined in vivo and stained with protargol. Our populations resemble the original one in terms of their live characters and cirral pattern. The main events during binary fission are as follows: (1) the parental adoral zone of membranelles is retained completely by the proter; (2) both in the proter and in the opisthe five frontal-ventral cirral anlagen are recognizable; (3) the marginal rows and dorsal kineties develop intrakinetally. In addition, the SSU rRNA gene was sequenced for the genus Parakahliella for the first time. Molecular phylogenetic analyses suggest that two populations of the genus Parakahliella cluster together and have a close relationship with species of Oxytrichidae.
Borong Lu, Daode Ji, Yalan Sheng, Weibo Song, Xiaozhong Hu, Xiangrui Chen, Khaled A. S. Al-Rasheid
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 123-143
https://doi.org/10.4467/16890027AP.18.011.8985Alma G. Islas-Ortega, Rogelio Aguilar-Aguilar, Paula S. Marcotegui , Sergio R. Martorelli, David Hernández-Mena, Gerardo Pérez-Ponce de León
Acta Protozoologica, Volume 57, Issue 2, 2018, pp. 145-151
https://doi.org/10.4467/16890027AP.18.012.8986Trichodina rectuncinata is one of the trichodinids most widely distributed in marine fish. This ciliate species has been recorded in more than 20 host species belonging to 17 fish families worldwide. Previous comparative studies based on morphometric data revealed considerable morphological variation among specimens from different populations of T. rectuncinata. In this study, we conducted a morphometric-molecular analysis of three populations of T. rectuncinata to evaluate potential differences among 18S rRNA sequences, in relation to morphological variations. Smears were obtained from marine fishes in three localities along the Pacific coast of Mexico. Based on the shape of denticles, we found four different morphotypes for T. rectuncinata. This morphological variability does not correspond with the genetic divergence, suggesting that all analyzed populations belong to the same species. Further analyses using more variable markers are necessary to corroborate the findings of our study.
Publication date: 06.04.2018
Editor-in-Chief: Krzysztof Wiąckowski
O. Roger Anderson
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 1-28
https://doi.org/10.4467/16890027AP.18.001.8395This is a review of over 400 published research papers on free-living, non-testate amoebae during the approximate last half century (1965-2017) particularly focusing on three topics: Biogeography, Ecology, and Physiology. These topics were identified because of the substantial attention given to them during the course of the last half century, and due to their potential importance in issues of local and global expanse, such as: aquatic and terrestrial stability of habitats, ecosystem processes, biogeochemistry and climate change, and the role of eukaryotic microbes generally in ecosystem services. Moreover, there are close epistemological and thematic ties among the three topics, making a synthesis of the published research more systematic and productive. The number of reviewed publications for each of the three individual topics is presented to illustrate the trends in publication frequencies during the historical period of analysis. Overall, the number of total publications reviewed varied somewhat between 1965 and early 2000 (generally less than 10 per year), but increased to well over 10 per year after 2000. The number of Biogeography and Ecology studies identified in the online citations increased substantially after the mid 1990s, while studies focusing on Physiology were relatively more abundant in the first decade (1965-1974) and less were identified in the 1985 to 2004 period. Citations to the literature are listed in tables for each of the three topics for convenience in retrieving references to specific aspects, and representative examples of the cited research in the tables are reviewed in the text under subheads dedicated to each of the three topics. Biogeographic studies largely focused on the geographic distribution and localized patterns of occurrence of amoebae, with more recent studies incorporating more attention to likely correlates with environmental and biotic factors in the distribution and community composition of amoebae. Ecological studies reviewed in the later decades tended to focus more on community dynamics, the effects of environmental variables on communities (including climate-related topics), a trend toward more physiological ecology studies, combined field-based and experimental studies, and incorporation of newer methodologies such as molecular genetics. In general, physiology studies in the first decades of the review tended to focus on topics of cell physiology such as basic biochemistry, enzyme assays, mechanisms of cell division and development, encystment, and motility. Later studies examined broader topics such as osmoregulation, nutrition, fine structure evidence of cellular changes during the life cycle (including encystment and excystment), and issues related to asexual and sexual reproduction, with increasing substantial evidence of evolutionary patterns and phylogenetics based on molecular evidence. A final section on Conclusions and Recommendations summarizes the findings and presents some potentially productive approaches to future research studies on Amoebozoa within the three designated topics of analysis.
Anna Glotova, Natalya Bondarenko, Alexey Smirnov
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 29-42
https://doi.org/10.4467/16890027AP.18.002.8396Piotr Solarczyk, Agnieszka Wojtkowiak-Giera, Marcin Hołysz, Anna Słodkowicz-Kowalska, Paweł P. Jagodziński, Krzysztof Stojecki, Anna Rocka, Anna C. Majewska, Łukasz Skrzypczak
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 43-48
https://doi.org/10.4467/16890027AP.18.003.8397iardia duodenalisis one of the six Giardia species and itis the most common, cosmopolitan flagellate that infects humans and many species of animals.This species exhibits considerable genetic diversity; to date, eight assemblages (A–H) have been defined. These assemblages differ in host specificity: assemblages A and B have beenfound in both humans and in many animal species. Mixed infections with Giardia (A and B) assemblages have been reported in humans and in animals. Many molecular techniques are effective and rapid for the detection of G. duodenalis and also forthe determination of genetic variability of isolates in clinical and environmental samples. In this context, the aim of this study was to design new assemblage-specific primers for rapid detection and identification ofG. duodenalis assemblages A and B and both of these assemblages simultaneously using quantitative real-time polymerase chain reaction (qPCR). Fragments of glutamate dehydrogenase and triose phosphate isomerase were used as targets in the design of primers.
In conclusion, the use of G. duodenalis assemblage-specific primers designed in this study allows quick identification of human infectious G. duodenalis assemblages A and B as well as mixed AB assemblages in a sample without further sequencing of the amplification products, which reduces the cost of study and the waiting time for the results.
Inna V Grushevaya, Anastasia N. Ignatieva, Svetlana M. Malysh, Igor V. Senderskiy , Ivan V. Zubarev, Anastasia G. Kononchuk
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 49-52
https://doi.org/10.4467/16890027AP.18.004.8398Microsporidia infection rate in Ostrinia nubilalis larvae collected in Russia in 2011-2016 ranged from 0 to 16 %. Totally, among 262 examined insects, there were as many as 13 infected specimens, resulting in average prevalence of 5 % over the period indicated. In all positive samples but one diplokaryotic spores 4 um long were observed corresponding to diagnosis of Nosema pyrausta. Nevertheless, in one case (i.e. 0.4 %) the infected larva contained monokaryotic spores about 2 um long. After experimental infection of a substitute host Ostrinia furnacalis with monokaryotic spores only Nosema-like spores were observed in laboratory assays. Ribosomal RNA and RPB1 gene portions were 100 % identical in samples of both mono- and diplokaryotic spores. This observation shows that Nosema pyrausta can form uninucleate spores under yet to be described conditions in nature and that molecular genetic analysis is essential for correct species identification.
Milena Svobodová , Jana Rádrová
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 53-59
https://doi.org/10.4467/16890027AP.18.005.8399Phlebotomine sandflies were tested as potential vectors of avian trypanosomes (Kinetoplastea: Trypanosomatidae). Lutzomyia longipalpis and Phlebotomus arabicus took bloodmeals with cultured Trypanosoma avium parasites; mature infections with stages transmissible to canaries (Serinus canaria) developed in the sandflies. The infection rates ranged between 66 and 89%, with heavy infections in 24 - 78% fed females. L. longipalpis that fed on infected birds were also infected, and some developed mature infections (37 and 19%, resp). On the contrary, Lutzomyia longipalpis and Phlebotomus arabicus were not susceptible to infection with trypanosomes from T. bennetti clade. Our results, together with the previous findings of naturally infected L. caballeroi, suggest that sandflies could serve as vectors of avian trypanosomes from the T. avium clade.
Franciane Cedrola, Priscila Fregulia, M. D'Agosto, Roberto Júnio Pedroso Dias
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 61-67
https://doi.org/10.4467/16890027AP.18.006.8400In our study, we aimed to identify and quantify the intestinal ciliates in a Brazilian capybara and to compare the obtained data with previous studies on the capybara ciliate community in other geographic locations within the American continent. We identified 20 species belonging to four families and ten genera. This is the first study on intestinal ciliates in Brazilian capybara since the last reports for the country in the 1960s. Among the identified species, Anacharon gracilis, A. lepturus, Cycloposthium bursa, Monoposthium cynodontum, Ogimotopsis pumila, Paracunhamunizia calocoma, Protohallia nana and Uropogon urai were recorded for the first time in Brazil, and the giant ciliate Muniziella cunhai was observed for the second time in a symbiotic association with capybaras in the country. The present study highlighted the importance of knowing the gastrointestinal ciliate community associated with wild hosts in order to better understand their geographic distribution and host specificity.
O. Roger Anderson
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 1-28
https://doi.org/10.4467/16890027AP.18.001.8395This is a review of over 400 published research papers on free-living, non-testate amoebae during the approximate last half century (1965-2017) particularly focusing on three topics: Biogeography, Ecology, and Physiology. These topics were identified because of the substantial attention given to them during the course of the last half century, and due to their potential importance in issues of local and global expanse, such as: aquatic and terrestrial stability of habitats, ecosystem processes, biogeochemistry and climate change, and the role of eukaryotic microbes generally in ecosystem services. Moreover, there are close epistemological and thematic ties among the three topics, making a synthesis of the published research more systematic and productive. The number of reviewed publications for each of the three individual topics is presented to illustrate the trends in publication frequencies during the historical period of analysis. Overall, the number of total publications reviewed varied somewhat between 1965 and early 2000 (generally less than 10 per year), but increased to well over 10 per year after 2000. The number of Biogeography and Ecology studies identified in the online citations increased substantially after the mid 1990s, while studies focusing on Physiology were relatively more abundant in the first decade (1965-1974) and less were identified in the 1985 to 2004 period. Citations to the literature are listed in tables for each of the three topics for convenience in retrieving references to specific aspects, and representative examples of the cited research in the tables are reviewed in the text under subheads dedicated to each of the three topics. Biogeographic studies largely focused on the geographic distribution and localized patterns of occurrence of amoebae, with more recent studies incorporating more attention to likely correlates with environmental and biotic factors in the distribution and community composition of amoebae. Ecological studies reviewed in the later decades tended to focus more on community dynamics, the effects of environmental variables on communities (including climate-related topics), a trend toward more physiological ecology studies, combined field-based and experimental studies, and incorporation of newer methodologies such as molecular genetics. In general, physiology studies in the first decades of the review tended to focus on topics of cell physiology such as basic biochemistry, enzyme assays, mechanisms of cell division and development, encystment, and motility. Later studies examined broader topics such as osmoregulation, nutrition, fine structure evidence of cellular changes during the life cycle (including encystment and excystment), and issues related to asexual and sexual reproduction, with increasing substantial evidence of evolutionary patterns and phylogenetics based on molecular evidence. A final section on Conclusions and Recommendations summarizes the findings and presents some potentially productive approaches to future research studies on Amoebozoa within the three designated topics of analysis.
Anna Glotova, Natalya Bondarenko, Alexey Smirnov
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 29-42
https://doi.org/10.4467/16890027AP.18.002.8396Piotr Solarczyk, Agnieszka Wojtkowiak-Giera, Marcin Hołysz, Anna Słodkowicz-Kowalska, Paweł P. Jagodziński, Krzysztof Stojecki, Anna Rocka, Anna C. Majewska, Łukasz Skrzypczak
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 43-48
https://doi.org/10.4467/16890027AP.18.003.8397iardia duodenalisis one of the six Giardia species and itis the most common, cosmopolitan flagellate that infects humans and many species of animals.This species exhibits considerable genetic diversity; to date, eight assemblages (A–H) have been defined. These assemblages differ in host specificity: assemblages A and B have beenfound in both humans and in many animal species. Mixed infections with Giardia (A and B) assemblages have been reported in humans and in animals. Many molecular techniques are effective and rapid for the detection of G. duodenalis and also forthe determination of genetic variability of isolates in clinical and environmental samples. In this context, the aim of this study was to design new assemblage-specific primers for rapid detection and identification ofG. duodenalis assemblages A and B and both of these assemblages simultaneously using quantitative real-time polymerase chain reaction (qPCR). Fragments of glutamate dehydrogenase and triose phosphate isomerase were used as targets in the design of primers.
In conclusion, the use of G. duodenalis assemblage-specific primers designed in this study allows quick identification of human infectious G. duodenalis assemblages A and B as well as mixed AB assemblages in a sample without further sequencing of the amplification products, which reduces the cost of study and the waiting time for the results.
Inna V Grushevaya, Anastasia N. Ignatieva, Svetlana M. Malysh, Igor V. Senderskiy , Ivan V. Zubarev, Anastasia G. Kononchuk
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 49-52
https://doi.org/10.4467/16890027AP.18.004.8398Microsporidia infection rate in Ostrinia nubilalis larvae collected in Russia in 2011-2016 ranged from 0 to 16 %. Totally, among 262 examined insects, there were as many as 13 infected specimens, resulting in average prevalence of 5 % over the period indicated. In all positive samples but one diplokaryotic spores 4 um long were observed corresponding to diagnosis of Nosema pyrausta. Nevertheless, in one case (i.e. 0.4 %) the infected larva contained monokaryotic spores about 2 um long. After experimental infection of a substitute host Ostrinia furnacalis with monokaryotic spores only Nosema-like spores were observed in laboratory assays. Ribosomal RNA and RPB1 gene portions were 100 % identical in samples of both mono- and diplokaryotic spores. This observation shows that Nosema pyrausta can form uninucleate spores under yet to be described conditions in nature and that molecular genetic analysis is essential for correct species identification.
Milena Svobodová , Jana Rádrová
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 53-59
https://doi.org/10.4467/16890027AP.18.005.8399Phlebotomine sandflies were tested as potential vectors of avian trypanosomes (Kinetoplastea: Trypanosomatidae). Lutzomyia longipalpis and Phlebotomus arabicus took bloodmeals with cultured Trypanosoma avium parasites; mature infections with stages transmissible to canaries (Serinus canaria) developed in the sandflies. The infection rates ranged between 66 and 89%, with heavy infections in 24 - 78% fed females. L. longipalpis that fed on infected birds were also infected, and some developed mature infections (37 and 19%, resp). On the contrary, Lutzomyia longipalpis and Phlebotomus arabicus were not susceptible to infection with trypanosomes from T. bennetti clade. Our results, together with the previous findings of naturally infected L. caballeroi, suggest that sandflies could serve as vectors of avian trypanosomes from the T. avium clade.
Franciane Cedrola, Priscila Fregulia, M. D'Agosto, Roberto Júnio Pedroso Dias
Acta Protozoologica, Volume 57, Issue 1, 2018, pp. 61-67
https://doi.org/10.4467/16890027AP.18.006.8400In our study, we aimed to identify and quantify the intestinal ciliates in a Brazilian capybara and to compare the obtained data with previous studies on the capybara ciliate community in other geographic locations within the American continent. We identified 20 species belonging to four families and ten genera. This is the first study on intestinal ciliates in Brazilian capybara since the last reports for the country in the 1960s. Among the identified species, Anacharon gracilis, A. lepturus, Cycloposthium bursa, Monoposthium cynodontum, Ogimotopsis pumila, Paracunhamunizia calocoma, Protohallia nana and Uropogon urai were recorded for the first time in Brazil, and the giant ciliate Muniziella cunhai was observed for the second time in a symbiotic association with capybaras in the country. The present study highlighted the importance of knowing the gastrointestinal ciliate community associated with wild hosts in order to better understand their geographic distribution and host specificity.
Publication date: 14.12.2017
Editor-in-Chief: Krzysztof Wiąckowski
Lingyun Chen, Xiaolu Zhao, Hamed A. El-Serehy, Jie Huang, John C. Clamp
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 221-233
https://doi.org/10.4467/16890027AP.17.020.7822Tachysoma pellionellum Stokes, 1887, a freshwater ciliate isolated from Stone Mountain State Park, North Carolina, was studied in vivo and after staining with protargol. The population was characterized mainly by having the typical 18 frontal-ventral-transverse cirri; posterior ends of left and right marginal rows not confluent; five dorsal kineties and one dorsomarginal kinety; two macronuclear nodules near left cell margin with one or two micronuclei between them; contractile vacuole located at mid-body near left margin. Morphogenesis is characterized as follows: (1) in the proter, the parental adoral zone of membranelles is retained completely; (2) 18 frontal-ventral-transverse cirri are derived from the anlage of the undulating membrane and the five streaks of the frontal-ventral-transverse anlagen; (3) marginal rows develop intrakinetally; (4) anlagen of dorsal kineties 1, 2 and 4 develop in the parental structure and anlagen of dorsal kineties 2 and 4 fragment in the posterior region forming anlagen of dorsal kineties 3 and 5; (5) only one dorsomarginal kinety formed; (6) the two macronuclear nodules fuse into a single mass, which then divides. Phylogenetic analyses based on sequences of the gene coding for SSU RNA revealed a close relationship between T. pellionellum and the Oxytricha clade, both of which grouped with Kleinstyla dorsicirrata and Heterourosomoida lanceolata.
Eleni Gentekaki, Chitchai Chantangsi
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 235-243
https://doi.org/10.4467/16890027AP.17.021.7823Opaline is an unusual group of protists, characterized by the presence of flagella covering their whole body. They reside in the intestinal tracts of various animals, most notably amphibians. While there is a wealth of data regarding the morphological features of opalines, molecular data are extremely sparse. Consequently, the extent of diversity of this understudied group remains unknown. Here, we examine opalines from the intestinal tract of the amphibian Hoplobatrachus rugulosus in Thailand. We provide micrographs obtained from light and scanning electron microscopy of various opalinid morphotypes. Furthermore, we enrich the database of opaline sequences by providing new molecular data of the small subunit ribosomal DNA gene of these species. In our phylogenetic analyses, the newly derived sequences form a cluster sister to Protoopalina.
Liesl L. van As, Linda Basson, Jo Van As
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 245-254
https://doi.org/10.4467/16890027AP.17.022.7824Members of the Urceolariidae Dujardin, 1941 have been found associated with a wide variety of invertebrate hosts from freshwater and marine habitats. Five species have been described from molluscan hosts from Europe and America. This paper deals with an urceolariid (Leiotrocha Fabre-Domergue, 1888) collected from the gills of Cellana radiata capensis (Gmelin, 1791) and Scutellastra exusta (Reeve, 1854) from the east coast of South Africa, as well as Patella depressa Pennant, 1777 and Cymbula safiana (Lamarck, 1891) from the bulge (west coast) of Africa. A higher prevalence was found on C. radiata capensis (89%) and P. depressa (72%) compared to the other two hosts. The urceolariid collected from the African limpets was identified as L. patellae (Cuénot, 1891). This is the first record of an urceolariid from any African hosts, including representatives of the Mollusca. Five urceolariid species were identified and described from gastropods, i.e. L. patellae Cuénot, 1891,U. karyolobia Hirshfield, 1949, U. cellanae Suzuki, 1950, U. viridis Richards, 1971 and U. parakorschelti Irwin, Sabetrasekh and Lynn, 2017. Motivation is provided why U. cellanae and U. viridis should be reallocated to the genus Leiotrocha, and U. karyolobia not. The taxonomic validity of the recent description of U. parakorschelti from limpets is commented on.
Ľubomír Rajter, Peter Vďačný
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 255-281
https://doi.org/10.4467/16890027AP.17.023.7825We investigated interrelationships between four free-living litostomatean lineages, using 18S rRNA gene and ITS region sequences as well as the secondary structure of the ITS2 molecules. Our phylogenetic analyses confirmed the deep split of free-living litostomateans into Rhynchostomatia and Haptoria represented here by Haptorida, Pleurostomatida, and Spathidiida. This bifurcation is also corroborated by the signature of the rhynchostomatian and haptorian ITS2 molecules. Specifically, the consensus stems of helices II and III are longer by one base pair in Rhynchostomatia, while the terminal loops of both helices are longer by one or two nucleotide/-s in Haptoria. A close relationship of Pleurostomatida and Haptorida is favored by quartet likelihood-mapping and supported by a 5’-AG vs. CU-3’ motif in the variable part of helix II and by two morphological apomorphies, i.e., meridionally extending somatic kineties and a non-three-rowed dorsal brush. Although monophyletic origin of Spathidiida is poorly supported in phylogenetic trees, the unique motif 5’-GA vs. UC-3’ present in the consensus helix II stem could be an important molecular synapomorphy of spathidiids, apart from the ancestrally anteriorly curved somatic kineties and the three-rowed dorsal brush. The peculiar family Pseudoholophryidae has very likely found its phylogenetic home among spathidiids, as an early branching lineage.
Mustafa Yaman
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 283-288
https://doi.org/10.4467/16890027AP.17.024.7826Chrysomela populi L. (Coleoptera; Chrysomelidae) is one of the most serious pests affecting poplars. Chemical control is the most widely known suppressive method against this pest. This method is not acceptable in urban forests because of their proximity to people. Entomopathogenic organisms are environmentally friendly control agents and suppress the pest populations under natural conditions. In the present study, the occurrence and distribution ofanew entomopathogenic protist,aneogregarine, Ophryocystis anatoliensis (Apicomplexa) in C. populi populations andamember of the family Chrysomelidae is presented for the first time. In total, 90 of 2185 C.populiadults and larvae collected from 16 localities during three years (from 2013 to 2015) were found to be infected by this pathogen. Neogregarine infection was observed in 14 of 16 investigated C. populi populations. The infection was variable between the populations and years. These results confirm that the neogregarine pathogen hasahigh dispersal potential through the C. populi populations and can be an effective natural biological suppressing factor on the pest populations.
Jing Li, Kun Yang, Feizhou Chen, Wenxuan Lu, Ting Fang, Xiuxia Zhao, Haiyang Li, Kai Cui
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 289-301
https://doi.org/10.4467/16890027AP.17.025.7827Direct and indirect effects of crustacean zooplankton (cladocerans and copepods) are important regulators of ciliate communities, especially in eutrophic systems. However, it is not clear whether pseudodiaptomids (e.g., Schmackeria), one of the dominant calanoid copepods in Chinese lakes, effectively impacts natural ciliate communities. The impacts of small-bodied cladocerans (e.g., Bosmina) on ciliates are also controversial.
We performed an incubation experiment using winter lake water from Lake Chaohu to assess the structuring effects that crustacean zooplankton have on natural ciliate populations. The presence and absence of cladocerans (Bosmina sp.) and copepods (Schmackeria inopinus) were alternated in four treatments.
Both Bosmina sp. and Schmackeria inopinus had substantial impacts on ciliate abundance, biomass, and community structure. The response of ciliates was different in the presence of Bosmina sp. compared with Schmackeria inopinus and varied among categories such as the ciliate population, relative body size and functional feeding group. Our results also highlight the importance of interference and exploitative competition among metazooplankton groups.
Xinlu Shi, Guijie Liu, Chundi Wang, Xiaozhong Hu
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 303-315
https://doi.org/10.4467/16890027AP.17.026.7828A brackish water euplotid ciliate, Uronychia xinjiangensis n. sp., was discovered in a ditch in Yuli County, Xinjiang, China. Its morphology, ciliature and morphogenesis were investigated based on specimens examined in vivo and following protargol staining. The new species is characterized by the posterior part of the adoral zone composed of three membranelles, which has never been seen in all other known congeners. Other morphologic features include: (i) body oval-shaped, with conspicuous right anterior spur-like protrusion;
(ii)size in vivo 60–90 × 40–68 μm; (iii) two macronuclear nodules; (iv) four frontal, two ventral, five transverse, three left marginal and three caudal cirri. Its morphogenesis proceeds in a usual way, except that the oral primordium forms only three proximal membranelles rather than four proximal membranelles within congeners. The small subunit rRNA gene of the new species (GenBank accession number: KX147287) comprises 1723 bp and 44.63% GC content, and differs by 0.12–1.81% from those of congeners. Phylogenetic analyses based on SSU rRNA gene sequence data reveal that Uronychia xinjiangensis n. sp. clusters with other Uronychia species with full support, which supports the monophyly of the genus Uronychia Stein, 1859.
Tania Tanveer, Abdul Hameed, Abdul-Aziz A. Bin-Dukhyil, Mohammed Alaidarous, Abdul Matin
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 317-322
https://doi.org/10.4467/16890027AP.17.027.7829Naegleria is well recognized for primary amoebic meningoencephalitis which always results into death. To date there is not a single report demonstrating molecular identification of Naegleria from water resources of Pakistan thus the aim of the proposed study.Here, in total 135 various water samples (like domestic tap water, municipal water, sea water, well water, tube well water, canal water, boring water, sewage water, lake water and stream water) were collected across Pakistan and evaluated for Naegleria species. Naegleria australiensis (pathogenic) and Naegleria lovaniensis (non pathogenic) were isolated on non nutrient agar plates and were further identified by PCR and sequencing. To best of our knowledge we have described for the first time the isolation and molecular identification of thermotolerant pathogenic and non pathogenicNaegleria species from diverse water samples including drinking water across Pakistan. The presence of pathogenic Naegleria species in diverse water samples may add the health threat to the community.
Lingyun Chen, Xiaolu Zhao, Hamed A. El-Serehy, Jie Huang, John C. Clamp
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 221-233
https://doi.org/10.4467/16890027AP.17.020.7822Tachysoma pellionellum Stokes, 1887, a freshwater ciliate isolated from Stone Mountain State Park, North Carolina, was studied in vivo and after staining with protargol. The population was characterized mainly by having the typical 18 frontal-ventral-transverse cirri; posterior ends of left and right marginal rows not confluent; five dorsal kineties and one dorsomarginal kinety; two macronuclear nodules near left cell margin with one or two micronuclei between them; contractile vacuole located at mid-body near left margin. Morphogenesis is characterized as follows: (1) in the proter, the parental adoral zone of membranelles is retained completely; (2) 18 frontal-ventral-transverse cirri are derived from the anlage of the undulating membrane and the five streaks of the frontal-ventral-transverse anlagen; (3) marginal rows develop intrakinetally; (4) anlagen of dorsal kineties 1, 2 and 4 develop in the parental structure and anlagen of dorsal kineties 2 and 4 fragment in the posterior region forming anlagen of dorsal kineties 3 and 5; (5) only one dorsomarginal kinety formed; (6) the two macronuclear nodules fuse into a single mass, which then divides. Phylogenetic analyses based on sequences of the gene coding for SSU RNA revealed a close relationship between T. pellionellum and the Oxytricha clade, both of which grouped with Kleinstyla dorsicirrata and Heterourosomoida lanceolata.
Eleni Gentekaki, Chitchai Chantangsi
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 235-243
https://doi.org/10.4467/16890027AP.17.021.7823Opaline is an unusual group of protists, characterized by the presence of flagella covering their whole body. They reside in the intestinal tracts of various animals, most notably amphibians. While there is a wealth of data regarding the morphological features of opalines, molecular data are extremely sparse. Consequently, the extent of diversity of this understudied group remains unknown. Here, we examine opalines from the intestinal tract of the amphibian Hoplobatrachus rugulosus in Thailand. We provide micrographs obtained from light and scanning electron microscopy of various opalinid morphotypes. Furthermore, we enrich the database of opaline sequences by providing new molecular data of the small subunit ribosomal DNA gene of these species. In our phylogenetic analyses, the newly derived sequences form a cluster sister to Protoopalina.
Liesl L. van As, Linda Basson, Jo Van As
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 245-254
https://doi.org/10.4467/16890027AP.17.022.7824Members of the Urceolariidae Dujardin, 1941 have been found associated with a wide variety of invertebrate hosts from freshwater and marine habitats. Five species have been described from molluscan hosts from Europe and America. This paper deals with an urceolariid (Leiotrocha Fabre-Domergue, 1888) collected from the gills of Cellana radiata capensis (Gmelin, 1791) and Scutellastra exusta (Reeve, 1854) from the east coast of South Africa, as well as Patella depressa Pennant, 1777 and Cymbula safiana (Lamarck, 1891) from the bulge (west coast) of Africa. A higher prevalence was found on C. radiata capensis (89%) and P. depressa (72%) compared to the other two hosts. The urceolariid collected from the African limpets was identified as L. patellae (Cuénot, 1891). This is the first record of an urceolariid from any African hosts, including representatives of the Mollusca. Five urceolariid species were identified and described from gastropods, i.e. L. patellae Cuénot, 1891,U. karyolobia Hirshfield, 1949, U. cellanae Suzuki, 1950, U. viridis Richards, 1971 and U. parakorschelti Irwin, Sabetrasekh and Lynn, 2017. Motivation is provided why U. cellanae and U. viridis should be reallocated to the genus Leiotrocha, and U. karyolobia not. The taxonomic validity of the recent description of U. parakorschelti from limpets is commented on.
Ľubomír Rajter, Peter Vďačný
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 255-281
https://doi.org/10.4467/16890027AP.17.023.7825We investigated interrelationships between four free-living litostomatean lineages, using 18S rRNA gene and ITS region sequences as well as the secondary structure of the ITS2 molecules. Our phylogenetic analyses confirmed the deep split of free-living litostomateans into Rhynchostomatia and Haptoria represented here by Haptorida, Pleurostomatida, and Spathidiida. This bifurcation is also corroborated by the signature of the rhynchostomatian and haptorian ITS2 molecules. Specifically, the consensus stems of helices II and III are longer by one base pair in Rhynchostomatia, while the terminal loops of both helices are longer by one or two nucleotide/-s in Haptoria. A close relationship of Pleurostomatida and Haptorida is favored by quartet likelihood-mapping and supported by a 5’-AG vs. CU-3’ motif in the variable part of helix II and by two morphological apomorphies, i.e., meridionally extending somatic kineties and a non-three-rowed dorsal brush. Although monophyletic origin of Spathidiida is poorly supported in phylogenetic trees, the unique motif 5’-GA vs. UC-3’ present in the consensus helix II stem could be an important molecular synapomorphy of spathidiids, apart from the ancestrally anteriorly curved somatic kineties and the three-rowed dorsal brush. The peculiar family Pseudoholophryidae has very likely found its phylogenetic home among spathidiids, as an early branching lineage.
Mustafa Yaman
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 283-288
https://doi.org/10.4467/16890027AP.17.024.7826Chrysomela populi L. (Coleoptera; Chrysomelidae) is one of the most serious pests affecting poplars. Chemical control is the most widely known suppressive method against this pest. This method is not acceptable in urban forests because of their proximity to people. Entomopathogenic organisms are environmentally friendly control agents and suppress the pest populations under natural conditions. In the present study, the occurrence and distribution ofanew entomopathogenic protist,aneogregarine, Ophryocystis anatoliensis (Apicomplexa) in C. populi populations andamember of the family Chrysomelidae is presented for the first time. In total, 90 of 2185 C.populiadults and larvae collected from 16 localities during three years (from 2013 to 2015) were found to be infected by this pathogen. Neogregarine infection was observed in 14 of 16 investigated C. populi populations. The infection was variable between the populations and years. These results confirm that the neogregarine pathogen hasahigh dispersal potential through the C. populi populations and can be an effective natural biological suppressing factor on the pest populations.
Jing Li, Kun Yang, Feizhou Chen, Wenxuan Lu, Ting Fang, Xiuxia Zhao, Haiyang Li, Kai Cui
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 289-301
https://doi.org/10.4467/16890027AP.17.025.7827Direct and indirect effects of crustacean zooplankton (cladocerans and copepods) are important regulators of ciliate communities, especially in eutrophic systems. However, it is not clear whether pseudodiaptomids (e.g., Schmackeria), one of the dominant calanoid copepods in Chinese lakes, effectively impacts natural ciliate communities. The impacts of small-bodied cladocerans (e.g., Bosmina) on ciliates are also controversial.
We performed an incubation experiment using winter lake water from Lake Chaohu to assess the structuring effects that crustacean zooplankton have on natural ciliate populations. The presence and absence of cladocerans (Bosmina sp.) and copepods (Schmackeria inopinus) were alternated in four treatments.
Both Bosmina sp. and Schmackeria inopinus had substantial impacts on ciliate abundance, biomass, and community structure. The response of ciliates was different in the presence of Bosmina sp. compared with Schmackeria inopinus and varied among categories such as the ciliate population, relative body size and functional feeding group. Our results also highlight the importance of interference and exploitative competition among metazooplankton groups.
Xinlu Shi, Guijie Liu, Chundi Wang, Xiaozhong Hu
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 303-315
https://doi.org/10.4467/16890027AP.17.026.7828A brackish water euplotid ciliate, Uronychia xinjiangensis n. sp., was discovered in a ditch in Yuli County, Xinjiang, China. Its morphology, ciliature and morphogenesis were investigated based on specimens examined in vivo and following protargol staining. The new species is characterized by the posterior part of the adoral zone composed of three membranelles, which has never been seen in all other known congeners. Other morphologic features include: (i) body oval-shaped, with conspicuous right anterior spur-like protrusion;
(ii)size in vivo 60–90 × 40–68 μm; (iii) two macronuclear nodules; (iv) four frontal, two ventral, five transverse, three left marginal and three caudal cirri. Its morphogenesis proceeds in a usual way, except that the oral primordium forms only three proximal membranelles rather than four proximal membranelles within congeners. The small subunit rRNA gene of the new species (GenBank accession number: KX147287) comprises 1723 bp and 44.63% GC content, and differs by 0.12–1.81% from those of congeners. Phylogenetic analyses based on SSU rRNA gene sequence data reveal that Uronychia xinjiangensis n. sp. clusters with other Uronychia species with full support, which supports the monophyly of the genus Uronychia Stein, 1859.
Tania Tanveer, Abdul Hameed, Abdul-Aziz A. Bin-Dukhyil, Mohammed Alaidarous, Abdul Matin
Acta Protozoologica, Volume 56, Issue 4, 2017, pp. 317-322
https://doi.org/10.4467/16890027AP.17.027.7829Naegleria is well recognized for primary amoebic meningoencephalitis which always results into death. To date there is not a single report demonstrating molecular identification of Naegleria from water resources of Pakistan thus the aim of the proposed study.Here, in total 135 various water samples (like domestic tap water, municipal water, sea water, well water, tube well water, canal water, boring water, sewage water, lake water and stream water) were collected across Pakistan and evaluated for Naegleria species. Naegleria australiensis (pathogenic) and Naegleria lovaniensis (non pathogenic) were isolated on non nutrient agar plates and were further identified by PCR and sequencing. To best of our knowledge we have described for the first time the isolation and molecular identification of thermotolerant pathogenic and non pathogenicNaegleria species from diverse water samples including drinking water across Pakistan. The presence of pathogenic Naegleria species in diverse water samples may add the health threat to the community.
Publication date: 13.12.2017
Editor-in-Chief: Krzysztof Wiąckowski
Zoya I. Uspenskaya, Alexander L. Yudin
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 139-147
https://doi.org/10.4467/16890027AP.17.012.7493A previously unrecorded property of actinomycin D, a well-known antibiotic, was discovered in the course of long-term genetic research on the amoeba Amoeba proteus and the ciliate Dileptus anser. In these protists actinomycin D can induce an unusual type of hereditary variation, which we refer to as the inheritable destabilization of characters. A number of features indicate that this variation is epigenetic, that is, not caused by mutations in the DNA. Therefore, actinomycin D may be considered as an inducer of epigenetic inheritable changes, in other words, as an epimutagen.
Xin Sheng, Yan Sheng, Yuehua Liu, Junhua Wang
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 149-160
https://doi.org/10.4467/16890027AP.17.013.7494Ji Hye Moon, Ji Hye Kim, Jae-Ho Jung
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 161-169
https://doi.org/10.4467/16890027AP.17.014.7495Brackish water populations of Pinacocoleps pulcher were collected from a lagoon in Korea. This species has never been described using silver impregnation and nuclear small subunit ribosomal RNA (SSU rRNA) gene. In the present study, we investigated the morphological and molecular attributes of P. pulcher using standard methods. The morphology was studied based on observations of live materials, silver-impregnated preparations, and scanning electron microscopy. The morphological characteristics are as follows: body size 80–90 × 40–50 µm in vivo, shape broadly ellipsoidal, body cross-section ellipsoidal, about seven anterior spines and about seven posterior spines, approximately 21 somatic ciliary rows, one macronucleus and one micronucleus, and a single caudal cilium. The SSU rRNA gene tree supports a sister relationship of P. pulcher to the genus Apocoleps, not P. tesselatus.
Gözde Gürelli, Fatma Tül Büşra Akman
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 171-180
https://doi.org/10.4467/16890027AP.17.015.7496Alvaro De Obeso Fernadez Del Valle, Sutherland K. Maciver
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 181-189
https://doi.org/10.4467/16890027AP.17.016.7497We report the isolation of a new species of Allovahlkampfia, a small cyst-forming heterolobosean soil amoeba. Phylogenetic analysis of the 18S rDNA and the internal transcribed spacers indicates that Allovahlkampfia is more closely related to the acrasids than to other heterolobosean groups and indicates that the new strain (GF1) groups with Allovahlkampfia tibetiensis and A. nederlandiensis despite being significantly smaller than these and any other described Allovahlkampfia species. GF1 forms aggregated cyst masses similar to the early stages of Acrasis sorocarp development, in agreement with the view that it shares ancestry with the acrasids. Time-lapse video microscopy reveals that trophozoites are attracted to individuals that have already begun to encyst or that have formed cysts. Although some members of the genus are known to be pathogenic the strain GF1 does not grow above 28oC nor at elevated osmotic conditions, indicating that it is unlikely to be a pathogen.
Isabelle Koenig, Florence Schwendener, Matthieu Mulot, Edward A. D. Mitchell
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 191-210
https://doi.org/10.4467/16890027AP.17.017.7498Satoshi D. Shimano, Anatoly Bobrov, Manfred Wanner, Mariusz Lamentowicz, Yuri Mazei, Taisuke Ohtsuka
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 211-216
https://doi.org/10.4467/16890027AP.17.018.7499John R. Dolan, Eun Jin Yang
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 217-220
https://doi.org/10.4467/16890027AP.17.019.7500Zoya I. Uspenskaya, Alexander L. Yudin
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 139-147
https://doi.org/10.4467/16890027AP.17.012.7493A previously unrecorded property of actinomycin D, a well-known antibiotic, was discovered in the course of long-term genetic research on the amoeba Amoeba proteus and the ciliate Dileptus anser. In these protists actinomycin D can induce an unusual type of hereditary variation, which we refer to as the inheritable destabilization of characters. A number of features indicate that this variation is epigenetic, that is, not caused by mutations in the DNA. Therefore, actinomycin D may be considered as an inducer of epigenetic inheritable changes, in other words, as an epimutagen.
Xin Sheng, Yan Sheng, Yuehua Liu, Junhua Wang
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 149-160
https://doi.org/10.4467/16890027AP.17.013.7494Ji Hye Moon, Ji Hye Kim, Jae-Ho Jung
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 161-169
https://doi.org/10.4467/16890027AP.17.014.7495Brackish water populations of Pinacocoleps pulcher were collected from a lagoon in Korea. This species has never been described using silver impregnation and nuclear small subunit ribosomal RNA (SSU rRNA) gene. In the present study, we investigated the morphological and molecular attributes of P. pulcher using standard methods. The morphology was studied based on observations of live materials, silver-impregnated preparations, and scanning electron microscopy. The morphological characteristics are as follows: body size 80–90 × 40–50 µm in vivo, shape broadly ellipsoidal, body cross-section ellipsoidal, about seven anterior spines and about seven posterior spines, approximately 21 somatic ciliary rows, one macronucleus and one micronucleus, and a single caudal cilium. The SSU rRNA gene tree supports a sister relationship of P. pulcher to the genus Apocoleps, not P. tesselatus.
Gözde Gürelli, Fatma Tül Büşra Akman
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 171-180
https://doi.org/10.4467/16890027AP.17.015.7496Alvaro De Obeso Fernadez Del Valle, Sutherland K. Maciver
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 181-189
https://doi.org/10.4467/16890027AP.17.016.7497We report the isolation of a new species of Allovahlkampfia, a small cyst-forming heterolobosean soil amoeba. Phylogenetic analysis of the 18S rDNA and the internal transcribed spacers indicates that Allovahlkampfia is more closely related to the acrasids than to other heterolobosean groups and indicates that the new strain (GF1) groups with Allovahlkampfia tibetiensis and A. nederlandiensis despite being significantly smaller than these and any other described Allovahlkampfia species. GF1 forms aggregated cyst masses similar to the early stages of Acrasis sorocarp development, in agreement with the view that it shares ancestry with the acrasids. Time-lapse video microscopy reveals that trophozoites are attracted to individuals that have already begun to encyst or that have formed cysts. Although some members of the genus are known to be pathogenic the strain GF1 does not grow above 28oC nor at elevated osmotic conditions, indicating that it is unlikely to be a pathogen.
Isabelle Koenig, Florence Schwendener, Matthieu Mulot, Edward A. D. Mitchell
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 191-210
https://doi.org/10.4467/16890027AP.17.017.7498Satoshi D. Shimano, Anatoly Bobrov, Manfred Wanner, Mariusz Lamentowicz, Yuri Mazei, Taisuke Ohtsuka
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 211-216
https://doi.org/10.4467/16890027AP.17.018.7499John R. Dolan, Eun Jin Yang
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 217-220
https://doi.org/10.4467/16890027AP.17.019.7500Publication date: 24.11.2017
Editor-in-Chief: Krzysztof Wiąckowski
Fernando Gómez, Kostas Kiriakoulakis, Enrique Lara
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 71-76
https://doi.org/10.4467/16890027AP.17.006.7481Simona Benčaťová, Eva Tirjaková
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 77-91
https://doi.org/10.4467/16890027AP.17.007.7482Renu Gupta, Jeeva Susan Abraham, Sripoorna Somasundaram, Ravi Toteja, Seema Makhija, Hamed A. El-Serehy
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 93-107
https://doi.org/10.4467/16890027AP.17.008.7483Alexander V. Kurilov
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 109-118
https://doi.org/10.4467/16890027AP.17.009.7484Maria A. Sousa, Barbara N. Santos, Cristina Carvalhal, Mario Steindel
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 119-127
https://doi.org/10.4467/16890027AP.17.010.7485Hubert Okła, Krzysztof Piotr Jasik, Beata Rozwadowska, Jan Słodki, Danuta Urbańska-Jasik, Michał Grelowski, Ewa Chmielik, Aleksandra Słodki, Marta Albertyńska, Aniela Grajoszek
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 129-137
https://doi.org/10.4467/16890027AP.17.011.7486Fernando Gómez, Kostas Kiriakoulakis, Enrique Lara
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 71-76
https://doi.org/10.4467/16890027AP.17.006.7481Simona Benčaťová, Eva Tirjaková
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 77-91
https://doi.org/10.4467/16890027AP.17.007.7482Renu Gupta, Jeeva Susan Abraham, Sripoorna Somasundaram, Ravi Toteja, Seema Makhija, Hamed A. El-Serehy
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 93-107
https://doi.org/10.4467/16890027AP.17.008.7483Alexander V. Kurilov
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 109-118
https://doi.org/10.4467/16890027AP.17.009.7484Maria A. Sousa, Barbara N. Santos, Cristina Carvalhal, Mario Steindel
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 119-127
https://doi.org/10.4467/16890027AP.17.010.7485Hubert Okła, Krzysztof Piotr Jasik, Beata Rozwadowska, Jan Słodki, Danuta Urbańska-Jasik, Michał Grelowski, Ewa Chmielik, Aleksandra Słodki, Marta Albertyńska, Aniela Grajoszek
Acta Protozoologica, Volume 56, Issue 2, 2017, pp. 129-137
https://doi.org/10.4467/16890027AP.17.011.7486Publication date: 22.09.2017
Editor-in-Chief: Krzysztof Wiąckowski
Noriyuki Kawano, Ryoji Funadani, Mikihiko Arikawa, Tetsuo Harada, Futoshi Suizu, Kou Matsuoka, Tatsuomi Matsuoka
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 1-7
https://doi.org/10.4467/16890027AP.17.001.6965We found that vegetative cells of Colpoda cucullus Nag-1 accumulated in shaded areas of a container when grown in the laboratory and then formed resting cysts. The photodispersal (negative photoaccumulation) of C. cucullus was mediated, at least in part, by a difference in forward swimming velocity between the illuminated region and the shaded area of the Petri dish (motion slowed or stopped in the shaded area). When C. cucullus was stimulated by continuous light irradiation, the forward swimming velocity increased and reached a steady state within 10 s. When the light intensity decreased, the forward swimming velocity gradually decreased, and eventually returned to its original level for approximately 1 min. The action spectrum of the photokinetic response (steady-state swimming acceleration driven by continuous light stimulation) implies the involvement of blue light receptors.
Jae-Ho Jung, Kyung-Min Park, Gi-Sik Min
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 9-16
https://doi.org/10.4467/16890027AP.17.002.6966We collected an 18-cirri oxytrichid ciliate from the brackish lagoon Songjiho, South Korea, in March 2012. Based on analyses of morphological and molecular attributes, we conclude that it is new genus and species. Pseudocyrtohymenides lacunae nov. gen., nov. spec. has similar morphological attributes to the genus Pseudocyrtohymena, however, the former species lacks caudal cirri. The sequence similarity of the nuclear small subunit ribosomal RNA (SSU rRNA) gene was 99.4% (10 nt difference) between Pseudocyrtohymenides lacunae and Pseudocyrtohymena koreana (type species).
Mingjian LIU, Lifang LI, Zhishuai Qu, Xiaotian Luo, Saleh A. Al-Farraj, Xiaofeng Lin, Xiaozhong Hu
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 17-37
https://doi.org/10.4467/16890027AP.17.003.6967The morphology and phylogeny of two poorly known species, Uronema nigricans (Müller, 1786) Florentin, 1901 and Lembadion lucens (Maskell, 1887) Kahl, 1931, were respectively collected from a eutrophic freshwater river in Shenzhen and an oligotrophic lake in Zhanjiang (both in southern China) and investigated using standard taxonomic methods. The sampled population of Uronema nigricanswas characterized by a cell size of 30–40 μm × 12–20 μm in vivo, an elongated elliptical outline with a prominent apical plate, and 13–15 somatic kineties. The sampled population of Lembadion lucenswas characterized by a cell size of 45–80 μm × 20–50 μm in vivo, 25–35 somatic kineties, five or six caudal kinetosomes with cilia about 20 μm in length, and a single right-positioned contractile vacuole.The small subunit ribosomal RNA gene (SSU rDNA) of these species was sequenced and compared with those of their congeners to reveal nucleotide differences. The phylogenetic trees showed that the Shenzhen population of Uronema nigricans clusters with two other sequences under the name of “Uronema nigricans” (which are possibly misidentified) and then groups with Uronemita sinensis (Pan et al., 2013) Liu et al., 2016 with full support. Phylogenetic analyses indicated that genus Lembadion is monophyletic with full support provided by both Bayesian inference and maximum likelihood algorithms. Based on analyses of morphological and sequence data, Uronemita sinensis may represent a new genus between Uronema and Uronemita.
Peter Vďačný, Wilhelm Foissner
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 39-57
https://doi.org/10.4467/16890027AP.17.004.6968The morphology and morphogenesis of a new Australian metopid ciliate, Lepidometopus platycephalus nov. gen., nov. spec., were studied using live observation, various silver impregnation methods, scanning electron microscopy, and morphometry. The new genus is outstanding in having epicortical scales (lepidosomes) and a strongly flattened and distinctly projecting preoral dome. Diagnostic features of L. platycephalus include a small, reniform body carrying an elongated caudal cilium, about 11 ciliary rows, and an adoral zone composed of an average of 11 polykinetids. The morphogenesis of L. platycephalus matches data from other metopids in that (1) the body is drastically re-shaped, (2) the parental oral structures are reorganized but do not contribute to the daughter oral ciliature, (3) the opisthe’s adoral polykinetids originate pleurotelokinetally, (4) the opisthe’s paroral membrane is formed via re-arrangement of the posterior portion of the first two perizonal rows, and (5) the opisthe’s perizonal stripe is made by three parental perizonal rows and two dorsolateral ciliary rows. The morphogenetic data corroborate phylogenetic analyses in that caenomorphids are only superficially similar to metopids; metopids and clevelandellids are closely related; and litostomateans are the best candidates for a sister group of the metopid-clevelandellid assemblage within the SAL superclade.
Yuri A. Mazei, Viktor Chernyshov, Sergei Bukhkalo, Natalia Mazei, Angela L. Creevy, Richard J. Payne
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 59-70
https://doi.org/10.4467/16890027AP.17.005.6969Testate amoebae are valued for their functional significance and application as indicators of environmental conditions, particularly in peatland ecosystems. Research on testate amoebae has increased dramatically in recent years but there are still large parts of the world which have seen very little research. Here we consider testate amoeba communities of the West Siberian Lowland, the world’s largest peatland region and therefore one of the largest potential habitats for testate amoebae. Extensive sampling identified 89 taxa and showed that testate amoeba communities are structured by their physical and biological environment. We identified significant relationships between amoeba communities and both moisture content and vegetation composition. Despite the assemblages containing many widely-distributed species, some taxa considered typical of peatlands (e.g. Archerella flavum and Hyalosphenia papilio) were comparatively rare or absent, paralleling findings further south in Asia. We suggest that testate amoebae in this region deserve further study and may have useful applications in palaeoecological reconstruction and as bioindicators of the impacts of oil and gas extraction.
Noriyuki Kawano, Ryoji Funadani, Mikihiko Arikawa, Tetsuo Harada, Futoshi Suizu, Kou Matsuoka, Tatsuomi Matsuoka
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 1-7
https://doi.org/10.4467/16890027AP.17.001.6965We found that vegetative cells of Colpoda cucullus Nag-1 accumulated in shaded areas of a container when grown in the laboratory and then formed resting cysts. The photodispersal (negative photoaccumulation) of C. cucullus was mediated, at least in part, by a difference in forward swimming velocity between the illuminated region and the shaded area of the Petri dish (motion slowed or stopped in the shaded area). When C. cucullus was stimulated by continuous light irradiation, the forward swimming velocity increased and reached a steady state within 10 s. When the light intensity decreased, the forward swimming velocity gradually decreased, and eventually returned to its original level for approximately 1 min. The action spectrum of the photokinetic response (steady-state swimming acceleration driven by continuous light stimulation) implies the involvement of blue light receptors.
Jae-Ho Jung, Kyung-Min Park, Gi-Sik Min
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 9-16
https://doi.org/10.4467/16890027AP.17.002.6966We collected an 18-cirri oxytrichid ciliate from the brackish lagoon Songjiho, South Korea, in March 2012. Based on analyses of morphological and molecular attributes, we conclude that it is new genus and species. Pseudocyrtohymenides lacunae nov. gen., nov. spec. has similar morphological attributes to the genus Pseudocyrtohymena, however, the former species lacks caudal cirri. The sequence similarity of the nuclear small subunit ribosomal RNA (SSU rRNA) gene was 99.4% (10 nt difference) between Pseudocyrtohymenides lacunae and Pseudocyrtohymena koreana (type species).
Mingjian LIU, Lifang LI, Zhishuai Qu, Xiaotian Luo, Saleh A. Al-Farraj, Xiaofeng Lin, Xiaozhong Hu
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 17-37
https://doi.org/10.4467/16890027AP.17.003.6967The morphology and phylogeny of two poorly known species, Uronema nigricans (Müller, 1786) Florentin, 1901 and Lembadion lucens (Maskell, 1887) Kahl, 1931, were respectively collected from a eutrophic freshwater river in Shenzhen and an oligotrophic lake in Zhanjiang (both in southern China) and investigated using standard taxonomic methods. The sampled population of Uronema nigricanswas characterized by a cell size of 30–40 μm × 12–20 μm in vivo, an elongated elliptical outline with a prominent apical plate, and 13–15 somatic kineties. The sampled population of Lembadion lucenswas characterized by a cell size of 45–80 μm × 20–50 μm in vivo, 25–35 somatic kineties, five or six caudal kinetosomes with cilia about 20 μm in length, and a single right-positioned contractile vacuole.The small subunit ribosomal RNA gene (SSU rDNA) of these species was sequenced and compared with those of their congeners to reveal nucleotide differences. The phylogenetic trees showed that the Shenzhen population of Uronema nigricans clusters with two other sequences under the name of “Uronema nigricans” (which are possibly misidentified) and then groups with Uronemita sinensis (Pan et al., 2013) Liu et al., 2016 with full support. Phylogenetic analyses indicated that genus Lembadion is monophyletic with full support provided by both Bayesian inference and maximum likelihood algorithms. Based on analyses of morphological and sequence data, Uronemita sinensis may represent a new genus between Uronema and Uronemita.
Peter Vďačný, Wilhelm Foissner
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 39-57
https://doi.org/10.4467/16890027AP.17.004.6968The morphology and morphogenesis of a new Australian metopid ciliate, Lepidometopus platycephalus nov. gen., nov. spec., were studied using live observation, various silver impregnation methods, scanning electron microscopy, and morphometry. The new genus is outstanding in having epicortical scales (lepidosomes) and a strongly flattened and distinctly projecting preoral dome. Diagnostic features of L. platycephalus include a small, reniform body carrying an elongated caudal cilium, about 11 ciliary rows, and an adoral zone composed of an average of 11 polykinetids. The morphogenesis of L. platycephalus matches data from other metopids in that (1) the body is drastically re-shaped, (2) the parental oral structures are reorganized but do not contribute to the daughter oral ciliature, (3) the opisthe’s adoral polykinetids originate pleurotelokinetally, (4) the opisthe’s paroral membrane is formed via re-arrangement of the posterior portion of the first two perizonal rows, and (5) the opisthe’s perizonal stripe is made by three parental perizonal rows and two dorsolateral ciliary rows. The morphogenetic data corroborate phylogenetic analyses in that caenomorphids are only superficially similar to metopids; metopids and clevelandellids are closely related; and litostomateans are the best candidates for a sister group of the metopid-clevelandellid assemblage within the SAL superclade.
Yuri A. Mazei, Viktor Chernyshov, Sergei Bukhkalo, Natalia Mazei, Angela L. Creevy, Richard J. Payne
Acta Protozoologica, Volume 56, Issue 1, 2017, pp. 59-70
https://doi.org/10.4467/16890027AP.17.005.6969Testate amoebae are valued for their functional significance and application as indicators of environmental conditions, particularly in peatland ecosystems. Research on testate amoebae has increased dramatically in recent years but there are still large parts of the world which have seen very little research. Here we consider testate amoeba communities of the West Siberian Lowland, the world’s largest peatland region and therefore one of the largest potential habitats for testate amoebae. Extensive sampling identified 89 taxa and showed that testate amoeba communities are structured by their physical and biological environment. We identified significant relationships between amoeba communities and both moisture content and vegetation composition. Despite the assemblages containing many widely-distributed species, some taxa considered typical of peatlands (e.g. Archerella flavum and Hyalosphenia papilio) were comparatively rare or absent, paralleling findings further south in Asia. We suggest that testate amoebae in this region deserve further study and may have useful applications in palaeoecological reconstruction and as bioindicators of the impacts of oil and gas extraction.
Publication date: 19.12.2016
Editor-in-Chief: Krzysztof Wiąckowski
Louis Beyens, Anatoly Bobrov
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 197-209
https://doi.org/10.4467/16890027AP.16.019.6006Anatoly Bobrov
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 211-219
https://doi.org/10.4467/16890027AP.16.020.6007Jordana C. Féres, Alfredo L. Porfírio-Sousa, Giulia M. Ribeiro, Gustavo M. Rocha, José Mauro Sterza, Maria Beatriz G. Souza, Carlos Eduardo A. Soares, Daniel J. G. Lahr
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 221-229
https://doi.org/10.4467/16890027AP.16.021.6008Arcellinida are free-living lobose amoebae that produce an outer shell (test). Here, we describe a conspicuous new species, Arcella gandalfi sp. nov, from Brazilian continental waters, along with a morphological and biometrical characterization. Test diameter and test height are on average 81 and 71 respectively. This new species has an apical conical extension, which differentiates it from other Arcella species. A. gandalfi seems to be closely-related to A. brasiliensis, due to the distinct marginal ring (test brim) present only in these two species. Since A. gandalfi is easily identified by morphological features and due to its apparent geographic restriction to South America, we discuss its possible use as a new flagship species.
Elena A. Gerasimova, Andrey O. Plotnikov
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 231-237
https://doi.org/10.4467/16890027AP.16.024.6011Two new species of centrohelids Acanthocystis lyra sp. nov. and A. siemensmae sp. nov. from the Pismenka River in the South Urals, Russia, have been studied with scanning electron microscopy. Cells of these species have both long and short spine scales with hollow shafts and circular basal plates. A. lyra has the long spine scales divided into two curved S-shaped branches possessing small teeth on their inner surface. The short spine scales have primary and secondary bifurcations. Every secondary branch ends with two teeth. A. siemensmae has both long and short scales with funnel-like apices, which possess small teeth. Based on the scale morphology A. lyra has been attributed to the A. turfacea species group, whereas A. siemensmae has been attributed to the A. pectinata species group, both according to classification proposed by Mikrjukov, 1997. Similarities and differences of the new species with other members of the genus Acanthocystis have been discussed.
Fernando Gómez, Kevin C. Wakeman, Aika Yamaguchi, Hisayoshi Nozaki
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 239-248
https://doi.org/10.4467/16890027AP.16.026.6095The dinoflagellate generaOxytoxum and Corythodinium that account for more than fifty species are widespread in warm oceans. These genera have been considered synonyms and thecal plate designations varied among authors. Several planktonic and sand-dwelling genera have been placed within the Oxytoxaceae. We obtained the first molecular data based on small subunit (SSU) rRNA gene sequences ofOxytoxum and Corythodinium, including the type species (O. scolopax and C. tessellatum) and C. frenguellii and C. cristatum. The three species of Corythodinium branched together a strong support [bootstrap (BP) of 98%]. This formed a sister clade with moderate support (BP 75%) with O. scolopax that supported the generic split. Oxytoxaceae should exclusively remain for Oxytoxum and Corythodinium, as an independent group, unrelated to any other known dinoflagellate. Oxytoxum was characterized by spindle-shaped cells with an anterior narrow epitheca, an apical spine and little cingular displacement. Corythodinium exhibits relatively broad cell shapes, with wider epitheca and greater cingular displacement, and an obovate or pentangular anterior sulcal plate that noticeably indented the epitheca. This suggested the need of new combinations for species that were described as Oxytoxum and possessed the characteristics of Corythodinium.
Paula S. Marcotegui , Linda Basson, Sergio R. Martorelli
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 249-257
https://doi.org/10.4467/16890027AP.16.027.6096During surveys of parasites of the pepper cory Corydoras paleatus Jenyns, 1842 and sided-livebearer Jenynsia multidentata Jenyns, 1842 from Samborombón River, Argentina, Trichodina corydori n. sp., Trichodina cribbi Dove and O’Donoghue, 2005 and T. jenynsii n. sp.were morphologically studied. Taxonomic and morphometric data for these trichodinids based on dry silver nitrate-impregnated specimens are presented. Trichodina corydori is characterized by a prominent blade apophysis, the section connecting the blade and central part is short, and the adoral ciliary spiral makes a turn of 370–380°. Trichodina jenynsii is characterized by curved blades and prominently-shaped denticle rays that are characteristically extremely long, tapering to thin sharp points in adult specimens. This study is the first formal report of these trichodinids from South America, and the description of two new species.
Graça Casal, Edilson Rodrigues Matos, Sónia Rocha, José Sindeaux Neto, Saleh Al-Quraishy, Carlos Azevedo
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 259-268
https://doi.org/10.4467/16890027AP.16.022.6009Jiří Vávra, Miroslav Hyliš, Ivan Fiala, Dominik Refardt, J. I. Ronny Larsson
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 269-280
https://doi.org/10.4467/16890027AP.16.023.6010Lanatospora costatasp. n., a new microsporidian parasite of the adipose and connective tissue cells of Megacyclops viridis (Jurine, 1820) (Copepoda: Cyclopidae) is described. It was isolated from a woodland pool with a rich and diverse fauna of microsporidia-infected small crustaceans and insect larvae. The parasite is structurally similar to the genus Lanatospora Voronin, 1989, characterized by a complex decorated exospore. In the described species the exospore is armoured by a conspicuous layer of interwoven ribs forming labyrinth on the spore surface. SSU rRNA phylogeny places the organism in the “aquatic outgroup” of microsporidia (Vossbrinck et al. 2004), which includes a number of microsporidia from aquatic microcrustacea of the classes Copepoda and Cladocera. The increasing number of available SSU rRNA gene sequences of these microsporidia allows a more detailed interpretation of their developmental histories.
Lamjed Mansour, Aouatef Thabet, Abdel Halim Harrath, Suliman Y. Al Omar, Ahmed Mukhtar, Shaban R. Sayed, Abdel-Azeem S. Abdel-Baki
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 281-290
https://doi.org/10.4467/16890027AP.16.028.6097A new microsporidia Glugea sardinellensis n. sp. found in the teleost fish Sardinella aurita Valenciennes collected from the Tunisian coasts. The parasite develops in a large xenomas measuring 1–16 mm in diameter and is generally visible with naked eye in the connective tissue around the pyloric caeca of the host. Xenoma were often rounded, but would be occasionally ovoid or irregular shape, generally creamy but rarely opaque, and filled with mature spores. The spores were unikaryotic pyriform measuring 5–5.5 (5.25±0.24) µm in length and 2.5–3 (2.75±0.24) µm in width. The posterior vacuole was large and occupied more than half of the spore. Ultrastructural study indicated that the mature spore has 13–14 coils of polar filament arranged in one layer, and a rough exospore. Intermediate stages were rare and randomly distributed in the xenoma. Merogonial and sporogonial stages were uni or binucleate. The plasma membrane surrounding the meront was irregular and indented. The mean prevalence was 18.3% and it varied according to season and locality. The distribution of prevalence according to fish size indicated that small fish were primarily affected. Phylogenetic analysis using the partial sequence of the SSU rDNA showed consistent association with species of the genusGlugea. The most closely related species was Glugea atherinae Berrebi, 1979 with 98.5% similarity.
Louis Beyens, Anatoly Bobrov
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 197-209
https://doi.org/10.4467/16890027AP.16.019.6006Anatoly Bobrov
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 211-219
https://doi.org/10.4467/16890027AP.16.020.6007Jordana C. Féres, Alfredo L. Porfírio-Sousa, Giulia M. Ribeiro, Gustavo M. Rocha, José Mauro Sterza, Maria Beatriz G. Souza, Carlos Eduardo A. Soares, Daniel J. G. Lahr
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 221-229
https://doi.org/10.4467/16890027AP.16.021.6008Arcellinida are free-living lobose amoebae that produce an outer shell (test). Here, we describe a conspicuous new species, Arcella gandalfi sp. nov, from Brazilian continental waters, along with a morphological and biometrical characterization. Test diameter and test height are on average 81 and 71 respectively. This new species has an apical conical extension, which differentiates it from other Arcella species. A. gandalfi seems to be closely-related to A. brasiliensis, due to the distinct marginal ring (test brim) present only in these two species. Since A. gandalfi is easily identified by morphological features and due to its apparent geographic restriction to South America, we discuss its possible use as a new flagship species.
Elena A. Gerasimova, Andrey O. Plotnikov
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 231-237
https://doi.org/10.4467/16890027AP.16.024.6011Two new species of centrohelids Acanthocystis lyra sp. nov. and A. siemensmae sp. nov. from the Pismenka River in the South Urals, Russia, have been studied with scanning electron microscopy. Cells of these species have both long and short spine scales with hollow shafts and circular basal plates. A. lyra has the long spine scales divided into two curved S-shaped branches possessing small teeth on their inner surface. The short spine scales have primary and secondary bifurcations. Every secondary branch ends with two teeth. A. siemensmae has both long and short scales with funnel-like apices, which possess small teeth. Based on the scale morphology A. lyra has been attributed to the A. turfacea species group, whereas A. siemensmae has been attributed to the A. pectinata species group, both according to classification proposed by Mikrjukov, 1997. Similarities and differences of the new species with other members of the genus Acanthocystis have been discussed.
Fernando Gómez, Kevin C. Wakeman, Aika Yamaguchi, Hisayoshi Nozaki
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 239-248
https://doi.org/10.4467/16890027AP.16.026.6095The dinoflagellate generaOxytoxum and Corythodinium that account for more than fifty species are widespread in warm oceans. These genera have been considered synonyms and thecal plate designations varied among authors. Several planktonic and sand-dwelling genera have been placed within the Oxytoxaceae. We obtained the first molecular data based on small subunit (SSU) rRNA gene sequences ofOxytoxum and Corythodinium, including the type species (O. scolopax and C. tessellatum) and C. frenguellii and C. cristatum. The three species of Corythodinium branched together a strong support [bootstrap (BP) of 98%]. This formed a sister clade with moderate support (BP 75%) with O. scolopax that supported the generic split. Oxytoxaceae should exclusively remain for Oxytoxum and Corythodinium, as an independent group, unrelated to any other known dinoflagellate. Oxytoxum was characterized by spindle-shaped cells with an anterior narrow epitheca, an apical spine and little cingular displacement. Corythodinium exhibits relatively broad cell shapes, with wider epitheca and greater cingular displacement, and an obovate or pentangular anterior sulcal plate that noticeably indented the epitheca. This suggested the need of new combinations for species that were described as Oxytoxum and possessed the characteristics of Corythodinium.
Paula S. Marcotegui , Linda Basson, Sergio R. Martorelli
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 249-257
https://doi.org/10.4467/16890027AP.16.027.6096During surveys of parasites of the pepper cory Corydoras paleatus Jenyns, 1842 and sided-livebearer Jenynsia multidentata Jenyns, 1842 from Samborombón River, Argentina, Trichodina corydori n. sp., Trichodina cribbi Dove and O’Donoghue, 2005 and T. jenynsii n. sp.were morphologically studied. Taxonomic and morphometric data for these trichodinids based on dry silver nitrate-impregnated specimens are presented. Trichodina corydori is characterized by a prominent blade apophysis, the section connecting the blade and central part is short, and the adoral ciliary spiral makes a turn of 370–380°. Trichodina jenynsii is characterized by curved blades and prominently-shaped denticle rays that are characteristically extremely long, tapering to thin sharp points in adult specimens. This study is the first formal report of these trichodinids from South America, and the description of two new species.
Graça Casal, Edilson Rodrigues Matos, Sónia Rocha, José Sindeaux Neto, Saleh Al-Quraishy, Carlos Azevedo
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 259-268
https://doi.org/10.4467/16890027AP.16.022.6009Jiří Vávra, Miroslav Hyliš, Ivan Fiala, Dominik Refardt, J. I. Ronny Larsson
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 269-280
https://doi.org/10.4467/16890027AP.16.023.6010Lanatospora costatasp. n., a new microsporidian parasite of the adipose and connective tissue cells of Megacyclops viridis (Jurine, 1820) (Copepoda: Cyclopidae) is described. It was isolated from a woodland pool with a rich and diverse fauna of microsporidia-infected small crustaceans and insect larvae. The parasite is structurally similar to the genus Lanatospora Voronin, 1989, characterized by a complex decorated exospore. In the described species the exospore is armoured by a conspicuous layer of interwoven ribs forming labyrinth on the spore surface. SSU rRNA phylogeny places the organism in the “aquatic outgroup” of microsporidia (Vossbrinck et al. 2004), which includes a number of microsporidia from aquatic microcrustacea of the classes Copepoda and Cladocera. The increasing number of available SSU rRNA gene sequences of these microsporidia allows a more detailed interpretation of their developmental histories.
Lamjed Mansour, Aouatef Thabet, Abdel Halim Harrath, Suliman Y. Al Omar, Ahmed Mukhtar, Shaban R. Sayed, Abdel-Azeem S. Abdel-Baki
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 281-290
https://doi.org/10.4467/16890027AP.16.028.6097A new microsporidia Glugea sardinellensis n. sp. found in the teleost fish Sardinella aurita Valenciennes collected from the Tunisian coasts. The parasite develops in a large xenomas measuring 1–16 mm in diameter and is generally visible with naked eye in the connective tissue around the pyloric caeca of the host. Xenoma were often rounded, but would be occasionally ovoid or irregular shape, generally creamy but rarely opaque, and filled with mature spores. The spores were unikaryotic pyriform measuring 5–5.5 (5.25±0.24) µm in length and 2.5–3 (2.75±0.24) µm in width. The posterior vacuole was large and occupied more than half of the spore. Ultrastructural study indicated that the mature spore has 13–14 coils of polar filament arranged in one layer, and a rough exospore. Intermediate stages were rare and randomly distributed in the xenoma. Merogonial and sporogonial stages were uni or binucleate. The plasma membrane surrounding the meront was irregular and indented. The mean prevalence was 18.3% and it varied according to season and locality. The distribution of prevalence according to fish size indicated that small fish were primarily affected. Phylogenetic analysis using the partial sequence of the SSU rDNA showed consistent association with species of the genusGlugea. The most closely related species was Glugea atherinae Berrebi, 1979 with 98.5% similarity.
Publication date: 28.11.2016
Editor-in-Chief: Krzysztof Wiąckowski
Lora L. Shadwick, Matthew W. Brown, Alexander K. Tice, Frederick W. Spiegel
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 123-134
https://doi.org/10.4467/16890027AP.16.012.5744We describe a new protosteloid amoeba, Luapeleamoeba hula. Protosteloid amoebae, sometimes called protostelids, are sporocarpic amoebae that make fruiting bodies that consist of a stalk and one to a few spores. This new taxon was cultured from dead leaves of mamaki (Pipturus albidus) from the Manuka Natural Area Reserve, Hawai`i, USA. Light microscopic examination showed that this amoeba has a short, rigid stalk with a small apophysis and a spore that changes shape continuously until it is shed and crawls away from the stalk. In addition, this amoeba was initially observed to maintain a diurnal rhythm in which fruiting body formation occurred primarily in the late afternoon. This new species is unique in both its amoebal and fruiting body morphology. Spore deciduousness appears to be a result of shape changes in the spore itself. This is the fourth species of protosteloid amoeba described with a clearly described diurnal rhythm. In addition, previous molecular phylogenetic analyses suggested that this new species has SSU rRNA gene sequences that clearly separate it from any other protosteloid amoebae and place it as sister to Protacanthamoeba bohemica among the Acanthamoebidae family in Centramoebida of Amoebozoa. Because this new species’ amoebae do not fit into any of the centramoebid genera, we have proposed a new genus—Luapeleamoeba.
Kang-San Kim, Jae-Ho Jung, Gi-Sik Min
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 135-144
https://doi.org/10.4467/16890027AP.16.013.5745A new soil urostylid ciliate, Birojimia soyaensis nov. spec. was discovered from Soya Island, Incheon, South Korea. The species is described based on live and stained specimen observations, and 18S ribosomal RNA gene sequence analysis. Birojimia soyaensis nov. spec. is characterized by the following features: body slender, elongate, and somewhat twisted; body size in vivo 170–200 μm × 40–50 μm; contractile vacuole located at middle of left cell margin; cortical granules present; 37–48 adoral membranelles; 3 frontal and 2 frontoterminal cirri present; III/2 and buccal cirrus present; midventral pairs only; pretransverse ventral and transverse cirri present; 1 left and 4 right marginal rows, including 3 compound rows; 5 long dorsal kineties with 3 additional shortened kineties in anteriorly compound rows; 8–11 caudal cirri; 53–69 macronuclear nodules; and 2 or 3 micronuclei. Birojimia soyaensis nov. spec. is distinguished from B. terricola by cortical granule size (0.4–1.2 μm in diameter vs. 2–3 μm × 1–2 μm), cortical granule shape (mostly spherical vs. broadly ellipsoid to lenticular, respectively); number of caudal cirri (8–11 vs. 2–7), and number of dorsal bristle rows (8 vs. 6–7). Phylogenetic analysis suggests this new species is most closely related to the genus Hemicycliostyla.
Leilane Talita Fatoreto Schwind, Rodrigo Leite Arrieira, Claudia Costa Bonecker, Fábio Amodêo Lansac-Tôha
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 145-154
https://doi.org/10.4467/16890027AP.16.014.5746Shell composition is considered an important functional trait in testate amoebae community. Differences in the composition of shells may represent adaptations of these organisms to changes in the availability of environmental resources. We aimed to evaluate the influence of these environmental resources on the presence of different testate amoeba species, based on observation of one important functional trait (shell composition), in floodplain environments. We hypothesised that species diversity would increase with increased availability of food (chlorophyll-a; a critical environmental requirement). We also predicted that a higher concentration of suspended inorganic material would contribute to the occurrence of species that have an exogenous shell. Testate amoeba samples were taken between 2002 and 2011 in plankton of ten floodplain environments. A significant positive correlation was noted between the concentration of chlorophyll-a and the diversity of testate amoeba species according to a simple regression analysis. Furthermore, non-metric multidimensional scaling showed distinct groups with lower and higher concentration of suspended inorganic material. The occurrence of testate amoeba species with smaller exogenous shells was the most influenced by environments with higher concentrations of suspended inorganic material. Thus, our results emphasised that the evaluated environmental resources are important as assembly factors to shell traits in testate amoebae community.
Paul J. Bischoff, Kaitlynn Connington
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 155-160
https://doi.org/10.4467/16890027AP.16.015.5747Among the most prolific invasive plant species posing threats to the ecological balance of ecosystems in North America and Europe is Japanese knotweed (Fallopia japonica). In order to identify the potential role of protists in the invasive capacity of Japanese knotweed the winter abundances of naked amoebae in soils from three roadside thickets of Japanese knotweed were compared to nearby non-invaded sites. Japanese knotweed soils had higher abundances (t = 5.43, df, 16, p < 0.001) of amoebae than comparison sites. This is one of the first studies to document higher abundances of soil naked amoebae associated with an invasive plant, and may indicate more generally that below-ground abundances of amoebae can promote soil fertility and support the successful adaptation and expansion of some invasive plant species. Moreover, analysis of encysted vs. trophic forms of naked amoebae in the winter soil, provided evidence of freezeresistant, amoeba resting cells in soil samples from the natural environment in support of prior findings that were based solely on laboratory experimental evidence. Overall, high densities of naked amoebae in the winter soils of Japanese knotweed, some as resting cells capable of forming rapidly activated trophic stages, likely increase soil fertility and strengthen the species’ invasive capacity.
Deidre West, Linda Basson, Jo Van As
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 161-171
https://doi.org/10.4467/16890027AP.16.016.5748Members of the genus Trichodina are mostly found on fish, but have also been recorded from a variety of other aquatic organisms, including calanoid copepods. So far, it appears that all the trichodinid populations collected from calanoids in various parts of the world are the same species, i.e. Trichodina diaptomi Šrámek-Hušek, 1953. This paper reports on a new record of T. diaptomi from Metadiaptomus meridianus in a large reservoir in South Africa, as well as on a new host species, Metadiaptomus transvaalensis, and the first record of T. diaptomi from pools in an ephemeral river in northern Botswana, therefore adding a new country to the distribution of this species. We used the history of the discovery of T. diaptomi in different parts of the world and came to the conclusion that it is a cosmopolitan species, exclusively associated with copepods of the order Calanoida. Based on existing information, T. diaptomi does not appear to have a reservoir host. Against this background, we provide a discussion on the possibility that, although no dormant stage has been recorded for any trichodinid, it may be possible that T. diaptomi possesses some form of diapause and that this might be related to that of calanoid copepods.
Eva Tirjaková, Katarína Krajčovičová, Marta Illyová, Peter Vďačný
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 173-188
https://doi.org/10.4467/16890027AP.16.017.5749The response of ciliate communities to cyanobacterial bloom was investigated in a shallow, hypertrophic reservoir in Slovakia, central Europe. Seasonal dynamics of ciliate communities corresponded negatively with course of water bloom formation. The highest numbers and abundances of ciliate species occurred during the spring season when cyanobacterial bloom was not fully developed, while there was an abrupt decrease in both numbers and abundances at the beginning of summer when water bloom culminated. Cyanobacterial blooming thus significantly lowered diversity and equitability of ciliate communities: many rare and sporadic species disappeared and few common taxa flourished and dominated. Nonetheless, these leading ciliates formed a functionally diverse assemblage whose members showed mostly positive contemporaneous and only rarely time-shifted interactions. There were fine filter feeders (Cinetochilum margaritaceum, Dexiotricha granulosa, Paramecium caudatum and Spirostomum teres) grazing heterotrophic bacteria and picocyanobacteria, omnivorous fine to coarse filter feeders (Frontonia leucas) as well as hunters (Coleps hirtus, Holophrya teres and Loxophyllum helus) looking for an individual prey. Also a comparatively rich, anaerobic coenosis comprising various bacterivorous armophoreans and plagiopyleans, developed at the bottom of the reservoir. Our study documents that ciliates form functionally diverse communities with potential to control cyanobacterial blooms in hypertrophic reservoirs.
O. Roger Anderson
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 189-196
https://doi.org/10.4467/16890027AP.16.018.5750Respiratory CO2 emissions from laboratory freshwater microcosms enriched with organic C (glucose and amino acids) and kept in the dark at 24°C were compared to control microcosms without C enrichment for two different freshwater pond sources. The purpose was to estimate experimentally the rate of respiratory CO2 emission from organically polluted freshwater ecosystems compared to non-enriched water. Experiment One, used pond water collected at the Lamont-Doherty Earth Observatory campus; and Experiment Two used pond water, inoculated with natural detritus, obtained from North Carolina. At peak respiration, the net efflux of CO2 (enriched minus control) to the atmosphere was ~ 90 nmol min–1 L–1 (Day 7, Experiment One) and ~ 240 nmol min–1 L–1 (Day 3, Experiment Two). The corresponding net efflux of C to the atmosphere was 25 nmol C min–1 L–1 (Day 7, Experiment One) and 65 nmol C min–1 L–1 (Day 3, Experiment Two). Peak CO2 emissions from the organic-enriched microcosms expressed as μmol m–2 s–1 (as more typically reported for natural bodies of water) were 0.20 for Experiment One, and 0.42 for Experiment Two, at a surface layer depth of approx. 20 cm, i.e. the microcosm depth. There was a relatively large correlation between respiratory CO2 emission and bacterial densities in the organic-C enriched microcosms (r = 0.76), but a smaller correlation (r = 0.32) in the non-enriched, control microcosm. Further broad scale research, robustly sampling natural bodies of organically polluted water, is needed to confirm and better establish the results of the research reported here using microcosms.
Lora L. Shadwick, Matthew W. Brown, Alexander K. Tice, Frederick W. Spiegel
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 123-134
https://doi.org/10.4467/16890027AP.16.012.5744We describe a new protosteloid amoeba, Luapeleamoeba hula. Protosteloid amoebae, sometimes called protostelids, are sporocarpic amoebae that make fruiting bodies that consist of a stalk and one to a few spores. This new taxon was cultured from dead leaves of mamaki (Pipturus albidus) from the Manuka Natural Area Reserve, Hawai`i, USA. Light microscopic examination showed that this amoeba has a short, rigid stalk with a small apophysis and a spore that changes shape continuously until it is shed and crawls away from the stalk. In addition, this amoeba was initially observed to maintain a diurnal rhythm in which fruiting body formation occurred primarily in the late afternoon. This new species is unique in both its amoebal and fruiting body morphology. Spore deciduousness appears to be a result of shape changes in the spore itself. This is the fourth species of protosteloid amoeba described with a clearly described diurnal rhythm. In addition, previous molecular phylogenetic analyses suggested that this new species has SSU rRNA gene sequences that clearly separate it from any other protosteloid amoebae and place it as sister to Protacanthamoeba bohemica among the Acanthamoebidae family in Centramoebida of Amoebozoa. Because this new species’ amoebae do not fit into any of the centramoebid genera, we have proposed a new genus—Luapeleamoeba.
Kang-San Kim, Jae-Ho Jung, Gi-Sik Min
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 135-144
https://doi.org/10.4467/16890027AP.16.013.5745A new soil urostylid ciliate, Birojimia soyaensis nov. spec. was discovered from Soya Island, Incheon, South Korea. The species is described based on live and stained specimen observations, and 18S ribosomal RNA gene sequence analysis. Birojimia soyaensis nov. spec. is characterized by the following features: body slender, elongate, and somewhat twisted; body size in vivo 170–200 μm × 40–50 μm; contractile vacuole located at middle of left cell margin; cortical granules present; 37–48 adoral membranelles; 3 frontal and 2 frontoterminal cirri present; III/2 and buccal cirrus present; midventral pairs only; pretransverse ventral and transverse cirri present; 1 left and 4 right marginal rows, including 3 compound rows; 5 long dorsal kineties with 3 additional shortened kineties in anteriorly compound rows; 8–11 caudal cirri; 53–69 macronuclear nodules; and 2 or 3 micronuclei. Birojimia soyaensis nov. spec. is distinguished from B. terricola by cortical granule size (0.4–1.2 μm in diameter vs. 2–3 μm × 1–2 μm), cortical granule shape (mostly spherical vs. broadly ellipsoid to lenticular, respectively); number of caudal cirri (8–11 vs. 2–7), and number of dorsal bristle rows (8 vs. 6–7). Phylogenetic analysis suggests this new species is most closely related to the genus Hemicycliostyla.
Leilane Talita Fatoreto Schwind, Rodrigo Leite Arrieira, Claudia Costa Bonecker, Fábio Amodêo Lansac-Tôha
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 145-154
https://doi.org/10.4467/16890027AP.16.014.5746Shell composition is considered an important functional trait in testate amoebae community. Differences in the composition of shells may represent adaptations of these organisms to changes in the availability of environmental resources. We aimed to evaluate the influence of these environmental resources on the presence of different testate amoeba species, based on observation of one important functional trait (shell composition), in floodplain environments. We hypothesised that species diversity would increase with increased availability of food (chlorophyll-a; a critical environmental requirement). We also predicted that a higher concentration of suspended inorganic material would contribute to the occurrence of species that have an exogenous shell. Testate amoeba samples were taken between 2002 and 2011 in plankton of ten floodplain environments. A significant positive correlation was noted between the concentration of chlorophyll-a and the diversity of testate amoeba species according to a simple regression analysis. Furthermore, non-metric multidimensional scaling showed distinct groups with lower and higher concentration of suspended inorganic material. The occurrence of testate amoeba species with smaller exogenous shells was the most influenced by environments with higher concentrations of suspended inorganic material. Thus, our results emphasised that the evaluated environmental resources are important as assembly factors to shell traits in testate amoebae community.
Paul J. Bischoff, Kaitlynn Connington
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 155-160
https://doi.org/10.4467/16890027AP.16.015.5747Among the most prolific invasive plant species posing threats to the ecological balance of ecosystems in North America and Europe is Japanese knotweed (Fallopia japonica). In order to identify the potential role of protists in the invasive capacity of Japanese knotweed the winter abundances of naked amoebae in soils from three roadside thickets of Japanese knotweed were compared to nearby non-invaded sites. Japanese knotweed soils had higher abundances (t = 5.43, df, 16, p < 0.001) of amoebae than comparison sites. This is one of the first studies to document higher abundances of soil naked amoebae associated with an invasive plant, and may indicate more generally that below-ground abundances of amoebae can promote soil fertility and support the successful adaptation and expansion of some invasive plant species. Moreover, analysis of encysted vs. trophic forms of naked amoebae in the winter soil, provided evidence of freezeresistant, amoeba resting cells in soil samples from the natural environment in support of prior findings that were based solely on laboratory experimental evidence. Overall, high densities of naked amoebae in the winter soils of Japanese knotweed, some as resting cells capable of forming rapidly activated trophic stages, likely increase soil fertility and strengthen the species’ invasive capacity.
Deidre West, Linda Basson, Jo Van As
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 161-171
https://doi.org/10.4467/16890027AP.16.016.5748Members of the genus Trichodina are mostly found on fish, but have also been recorded from a variety of other aquatic organisms, including calanoid copepods. So far, it appears that all the trichodinid populations collected from calanoids in various parts of the world are the same species, i.e. Trichodina diaptomi Šrámek-Hušek, 1953. This paper reports on a new record of T. diaptomi from Metadiaptomus meridianus in a large reservoir in South Africa, as well as on a new host species, Metadiaptomus transvaalensis, and the first record of T. diaptomi from pools in an ephemeral river in northern Botswana, therefore adding a new country to the distribution of this species. We used the history of the discovery of T. diaptomi in different parts of the world and came to the conclusion that it is a cosmopolitan species, exclusively associated with copepods of the order Calanoida. Based on existing information, T. diaptomi does not appear to have a reservoir host. Against this background, we provide a discussion on the possibility that, although no dormant stage has been recorded for any trichodinid, it may be possible that T. diaptomi possesses some form of diapause and that this might be related to that of calanoid copepods.
Eva Tirjaková, Katarína Krajčovičová, Marta Illyová, Peter Vďačný
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 173-188
https://doi.org/10.4467/16890027AP.16.017.5749The response of ciliate communities to cyanobacterial bloom was investigated in a shallow, hypertrophic reservoir in Slovakia, central Europe. Seasonal dynamics of ciliate communities corresponded negatively with course of water bloom formation. The highest numbers and abundances of ciliate species occurred during the spring season when cyanobacterial bloom was not fully developed, while there was an abrupt decrease in both numbers and abundances at the beginning of summer when water bloom culminated. Cyanobacterial blooming thus significantly lowered diversity and equitability of ciliate communities: many rare and sporadic species disappeared and few common taxa flourished and dominated. Nonetheless, these leading ciliates formed a functionally diverse assemblage whose members showed mostly positive contemporaneous and only rarely time-shifted interactions. There were fine filter feeders (Cinetochilum margaritaceum, Dexiotricha granulosa, Paramecium caudatum and Spirostomum teres) grazing heterotrophic bacteria and picocyanobacteria, omnivorous fine to coarse filter feeders (Frontonia leucas) as well as hunters (Coleps hirtus, Holophrya teres and Loxophyllum helus) looking for an individual prey. Also a comparatively rich, anaerobic coenosis comprising various bacterivorous armophoreans and plagiopyleans, developed at the bottom of the reservoir. Our study documents that ciliates form functionally diverse communities with potential to control cyanobacterial blooms in hypertrophic reservoirs.
O. Roger Anderson
Acta Protozoologica, Volume 55, Issue 3, 2016, pp. 189-196
https://doi.org/10.4467/16890027AP.16.018.5750Respiratory CO2 emissions from laboratory freshwater microcosms enriched with organic C (glucose and amino acids) and kept in the dark at 24°C were compared to control microcosms without C enrichment for two different freshwater pond sources. The purpose was to estimate experimentally the rate of respiratory CO2 emission from organically polluted freshwater ecosystems compared to non-enriched water. Experiment One, used pond water collected at the Lamont-Doherty Earth Observatory campus; and Experiment Two used pond water, inoculated with natural detritus, obtained from North Carolina. At peak respiration, the net efflux of CO2 (enriched minus control) to the atmosphere was ~ 90 nmol min–1 L–1 (Day 7, Experiment One) and ~ 240 nmol min–1 L–1 (Day 3, Experiment Two). The corresponding net efflux of C to the atmosphere was 25 nmol C min–1 L–1 (Day 7, Experiment One) and 65 nmol C min–1 L–1 (Day 3, Experiment Two). Peak CO2 emissions from the organic-enriched microcosms expressed as μmol m–2 s–1 (as more typically reported for natural bodies of water) were 0.20 for Experiment One, and 0.42 for Experiment Two, at a surface layer depth of approx. 20 cm, i.e. the microcosm depth. There was a relatively large correlation between respiratory CO2 emission and bacterial densities in the organic-C enriched microcosms (r = 0.76), but a smaller correlation (r = 0.32) in the non-enriched, control microcosm. Further broad scale research, robustly sampling natural bodies of organically polluted water, is needed to confirm and better establish the results of the research reported here using microcosms.
Publication date: 24.08.2016
Editor-in-Chief: Krzysztof Wiąckowski
Jeroen van Wichelen, Sofie d’Hondt, Myriam Claeys, Wim Vyverman, Cédric Berney, David Bass, Pieter Vanormelingen
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 61-87
https://doi.org/10.4467/16890027AP.16.007.4942The colonies of Microcystis, one of the most common bloom-forming cyanobacteria worldwide, harbor a diverse community of microorganisms. Among these, naked amoebae feeding on Microcystis cells can strongly influence natural Microcystis population dynamics. In this study, we investigated the species diversity of these amoebae based on 26 Microcystis-associated amoebae (MAA) strains from eutrophied water bodies in Belgium and elsewhere in western Europe. A detailed morphological characterization in combination with 18S rDNA (SSU) phylogenies revealed the presence of no less than 10 species. Nine of these belonged to the known genera Vannella (2 species), Korotnevella (2), Copromyxa (2), Vexillifera (1), Cochliopodium (1) and the recently described Angulamoeba (1). Only two were previously described, the others were new to science. One taxon could not be assigned to a known genus and is here described as Schoutedamoeba gen. n., representing a new variosean lineage. The discovery of so many new species from only one very specific habitat (Microcystis colonies) from a rather restricted geographical area indicates that the diversity of planktonic naked amoebae is much higher than previously appreciated and that only a tiny fraction of the total diversity of naked amoebae is currently known.
Jae-Ho Jung, Kyung-Min Park, Sanghee Kim
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 89-99
https://doi.org/10.4467/16890027AP.16.008.4943The soil ciliate Anteholosticha rectangula nov. spec. was discovered on King George Island in maritime Antarctica. Morphology and the nuclear SSU rDNA sequence were used to describe and infer the phylogenetic position of the new species. Anteholosticha rectangula is morphologically similar to A. bergeri and A. verrucosa, differing primarily by the morphology of the nuclear apparatus and dorsal kineties, respectively. The morphological features of related species are compared and discussed to confirm the validity of the new species. Molecular phylogenetic tree supports the previously reported polyphyly of the genus Anteholosticha.
Florian Gschwend, Aneta Majda, Wojciech Majewski, Jan Pawlowski
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 101-110
https://doi.org/10.4467/16890027AP.16.009.4944Psammophaga fuegiais a new monothalamid foraminifera discovered in surface sediment samples in the Beagle Channel, South America. The species is a member of the important, globally distributed genus Psammophaga, which has the ability to ingest and store mineral particles inside the cytoplasm. Its shape is ovoid to pyriform, the size varies from 250 to 600 µm in length and from 200 to 400 µm in width. Like other Psammophaga species P. fuegia has a single aperture. It was found in multiple samples across the Beagle Channel area at water depths of 4 to 220 meters and in environments as variable as fjords, the main channel, and the harbour of Puerto Williams (Chile). The occurrences of the new species in environmental DNA and RNA samples correspond well to its distribution inferred from the microscopic study.
Austin C. Walthall, Alexander K. Tice, Matthew W. Brown
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 111-117
https://doi.org/10.4467/16890027AP.16.010.4945We isolated and identified a freshwater amoebozoan species that belongs to the genus Flamella Schaeffer, 1926 by single cell isolation and light microscopy. Our specific strain was isolated from a water sample obtained on the cover of a swimming pool in Petal, Mississippi, USA collected during the winter of 2015. Morphologically, our isolate is a fan-shaped amoeba with a large, frontal hyaloplasm and distinctive granuloplasm. It is capable of encystment and trophozoites occasionally have two nuclei. The isolate (GFP151sc) is phylogenetically sister to but unique from the freshwater environmental flamellid clone from Borok, Yaroslavl region, Russia originally published in 2006. Here we describe and place this isolate into a new species, Flamella piscinae n. sp.
Alan Warren, Nettie Mcmiller, Lúcia Safi, Xiaozhong Hu, Jason Tarkington
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 119-121
https://doi.org/10.4467/16890027AP.16.011.4946Jeroen van Wichelen, Sofie d’Hondt, Myriam Claeys, Wim Vyverman, Cédric Berney, David Bass, Pieter Vanormelingen
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 61-87
https://doi.org/10.4467/16890027AP.16.007.4942The colonies of Microcystis, one of the most common bloom-forming cyanobacteria worldwide, harbor a diverse community of microorganisms. Among these, naked amoebae feeding on Microcystis cells can strongly influence natural Microcystis population dynamics. In this study, we investigated the species diversity of these amoebae based on 26 Microcystis-associated amoebae (MAA) strains from eutrophied water bodies in Belgium and elsewhere in western Europe. A detailed morphological characterization in combination with 18S rDNA (SSU) phylogenies revealed the presence of no less than 10 species. Nine of these belonged to the known genera Vannella (2 species), Korotnevella (2), Copromyxa (2), Vexillifera (1), Cochliopodium (1) and the recently described Angulamoeba (1). Only two were previously described, the others were new to science. One taxon could not be assigned to a known genus and is here described as Schoutedamoeba gen. n., representing a new variosean lineage. The discovery of so many new species from only one very specific habitat (Microcystis colonies) from a rather restricted geographical area indicates that the diversity of planktonic naked amoebae is much higher than previously appreciated and that only a tiny fraction of the total diversity of naked amoebae is currently known.
Jae-Ho Jung, Kyung-Min Park, Sanghee Kim
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 89-99
https://doi.org/10.4467/16890027AP.16.008.4943The soil ciliate Anteholosticha rectangula nov. spec. was discovered on King George Island in maritime Antarctica. Morphology and the nuclear SSU rDNA sequence were used to describe and infer the phylogenetic position of the new species. Anteholosticha rectangula is morphologically similar to A. bergeri and A. verrucosa, differing primarily by the morphology of the nuclear apparatus and dorsal kineties, respectively. The morphological features of related species are compared and discussed to confirm the validity of the new species. Molecular phylogenetic tree supports the previously reported polyphyly of the genus Anteholosticha.
Florian Gschwend, Aneta Majda, Wojciech Majewski, Jan Pawlowski
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 101-110
https://doi.org/10.4467/16890027AP.16.009.4944Psammophaga fuegiais a new monothalamid foraminifera discovered in surface sediment samples in the Beagle Channel, South America. The species is a member of the important, globally distributed genus Psammophaga, which has the ability to ingest and store mineral particles inside the cytoplasm. Its shape is ovoid to pyriform, the size varies from 250 to 600 µm in length and from 200 to 400 µm in width. Like other Psammophaga species P. fuegia has a single aperture. It was found in multiple samples across the Beagle Channel area at water depths of 4 to 220 meters and in environments as variable as fjords, the main channel, and the harbour of Puerto Williams (Chile). The occurrences of the new species in environmental DNA and RNA samples correspond well to its distribution inferred from the microscopic study.
Austin C. Walthall, Alexander K. Tice, Matthew W. Brown
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 111-117
https://doi.org/10.4467/16890027AP.16.010.4945We isolated and identified a freshwater amoebozoan species that belongs to the genus Flamella Schaeffer, 1926 by single cell isolation and light microscopy. Our specific strain was isolated from a water sample obtained on the cover of a swimming pool in Petal, Mississippi, USA collected during the winter of 2015. Morphologically, our isolate is a fan-shaped amoeba with a large, frontal hyaloplasm and distinctive granuloplasm. It is capable of encystment and trophozoites occasionally have two nuclei. The isolate (GFP151sc) is phylogenetically sister to but unique from the freshwater environmental flamellid clone from Borok, Yaroslavl region, Russia originally published in 2006. Here we describe and place this isolate into a new species, Flamella piscinae n. sp.
Alan Warren, Nettie Mcmiller, Lúcia Safi, Xiaozhong Hu, Jason Tarkington
Acta Protozoologica, Volume 55, Issue 2, 2016, pp. 119-121
https://doi.org/10.4467/16890027AP.16.011.4946Publication date: 17.02.2016
Editor-in-Chief: Krzysztof Wiąckowski
Klaus Hausmann, Gerd Günther, Diana Lehmann, Renate Radek
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 1-5
https://doi.org/10.4467/16890027AP.16.001.4042Oriol Canals, Humbert Salvadó
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 7-18
https://doi.org/10.4467/16890027AP.16.002.4043A new peritrich species highly tolerant to ammonium and nitrite, Epistylis camprubii n. sp., was found adhered to the biofilm of two advanced wastewater treatment plants treating high ammonium-loaded wastewater in Rubí, Spain. Its morphology, oral infraciliature and phylogenetic position in the peritrich clade were studied. The new species is a vase-shaped peritrich, constricted below the peristomial lip, with an in vivo average length of 58.7 ± 10.1 µm, average width of 32.0 ± 5.4 µm, and a longitudinally striated, compact stalk that occasionally exhibits uneven thickness and rarely shows transverse segments. The peristomial disc is commonly rounded or pointed, and rarely umbilicated. The C-shaped macronucleus is located in the adoral half of the body, and the only contractile vacuole lies in the adoral third of the zooid. The molecular analysis of the 18s gene sequence clustered E. camprubii n. sp. together with the other Epistylis, with the exception of Epistylis galea.
O. Roger Anderson
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 19-25
https://doi.org/10.4467/16890027AP.16.003.4044Helge Abildhauge Thomsen, Jorun Karin Egge
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 27-32
https://doi.org/10.4467/16890027AP.16.004.4045Helge Abildhauge Thomsen, Jette Buch Østergaard, Mikal Heldal
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 33-50
https://doi.org/10.4467/16890027AP.16.005.4046Yuri A. Mazei, Olga Belyakova, Olimpia Coppellotti, Richard J. Payne
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 51-59
https://doi.org/10.4467/16890027AP.16.006.4047Klaus Hausmann, Gerd Günther, Diana Lehmann, Renate Radek
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 1-5
https://doi.org/10.4467/16890027AP.16.001.4042Oriol Canals, Humbert Salvadó
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 7-18
https://doi.org/10.4467/16890027AP.16.002.4043A new peritrich species highly tolerant to ammonium and nitrite, Epistylis camprubii n. sp., was found adhered to the biofilm of two advanced wastewater treatment plants treating high ammonium-loaded wastewater in Rubí, Spain. Its morphology, oral infraciliature and phylogenetic position in the peritrich clade were studied. The new species is a vase-shaped peritrich, constricted below the peristomial lip, with an in vivo average length of 58.7 ± 10.1 µm, average width of 32.0 ± 5.4 µm, and a longitudinally striated, compact stalk that occasionally exhibits uneven thickness and rarely shows transverse segments. The peristomial disc is commonly rounded or pointed, and rarely umbilicated. The C-shaped macronucleus is located in the adoral half of the body, and the only contractile vacuole lies in the adoral third of the zooid. The molecular analysis of the 18s gene sequence clustered E. camprubii n. sp. together with the other Epistylis, with the exception of Epistylis galea.
O. Roger Anderson
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 19-25
https://doi.org/10.4467/16890027AP.16.003.4044Helge Abildhauge Thomsen, Jorun Karin Egge
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 27-32
https://doi.org/10.4467/16890027AP.16.004.4045Helge Abildhauge Thomsen, Jette Buch Østergaard, Mikal Heldal
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 33-50
https://doi.org/10.4467/16890027AP.16.005.4046Yuri A. Mazei, Olga Belyakova, Olimpia Coppellotti, Richard J. Payne
Acta Protozoologica, Volume 55, Issue 1, 2016, pp. 51-59
https://doi.org/10.4467/16890027AP.16.006.4047Publication date: 13.07.2015
Editor-in-Chief: Krzysztof Wiąckowski
Nicholas Bock, O. Roger Anderson
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 265-273
https://doi.org/10.4467/16890027AP.15.021.3535Lichens are widely recognized as important examples of a fungal-algal or fungal-cyanophyte symbiosis; and in some cases they are a major food source for some animal grazers such as caribou (Rangifer tarandus), especially in the Arctic during winter. However, relatively little is known about the ecology of their co-associated bacterial and protistan communities. This is one of the first reports of an analysis of microbial communities associated with rock-dwelling foliose lichens (Flavoparmeliasp.), including a more detailed analysis of the microbial communities associated with segments of the shield-like, radially arranged lobes. Samples were taken from lichens on granite boulders beneath an oak and maple tree stand on the Lamont-Doherty Earth Observatory Campus, Palisades, N.Y. The bacteria and protist members of the lichen associated microbial communities are comparable to recently reported associations for foliose lichens growing on tree bark at the same locale, including the presence of large myxomycete plasmodial amebas, heterotrophic nanoflagellates, and naked and testate amebas. To obtain evidence of possible differences in the microecology of different portions of each radial lobe, three segments of the radial lobe in the shield-like lichen were sampled: 1) inner, more mature, central segment; 2) middle section linking the central and peripheral segments; and 3) outer, peripheral, usually broader, less closely attached segment. The mean densities (number/g) and biomasses (µg/g) of bacteria and heterotrophic nanoflagellates were highest in the older central segment and lowest in the peripheral segment of the radial lobes, especially when expressed on moist weight basis. Large myxomycete plasmodial amebas were typically located in the outermost segment of the radial lobe. The proportion of vannellid amebas (Vannella spp. and Cochliopodium spp.) were significantly more abundant in the samples of the inner lobes compared to non-vannellid amebas that were more prevalent in the outer lobes. The outer segment of the thallus lobe was typically more spongiose and absorbed more water per unit weight (based on a wet/dry-weight ratio) than the innermost segment. In general, patterns of densities and taxonomic composition of bacteria and eukaryotic microbes intergraded from the inner most segment to the outer part of each lobe – indicating a possible microecological gradient, coincident with the age-related and morphological radial gradations of the lobe. Overall, the evidence shows that the radial variation in the morphology and age-related variables of the three lobe segments may affect the microenvironment of the lobe segments and hence influence the organization of the microbial communities within each segment.
Helge Abildhauge Thomsen, Jette Buch Østergaard, Lluïsa Cros
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 275-281
https://doi.org/10.4467/16890027AP.15.022.3536It has been known for some time that the distinctive polar weakly calcified coccolithophores are also present in samples from lower latitudes. While polar species may actually have a geographic range that vastly extends beyond the polar realms, it is often the case that the warm water regions contribute species that can be allocated to genera previously described based on polar material. We are currently in the process of formally dealing with the warm water species diversity affiliated with the family Papposphaeraceae. In this paper we describe a new genus and species Ventimolina stellata based on material from the Andaman Sea (type locality) and the NW Mediterranean.
Kenneth H. Nicholls
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 283-288
https://doi.org/10.4467/16890027AP.15.023.3537In 1961, the testate amoeba Nebela kivuense Gauthier-Lièvre et Thomas, 1961 was described for the first and only time from an area near Lake Edward in the Democratic Republic of the Congo (at 0.002° N Latitude). The lack of recent reports of this species, despite exhaustive surveys of the testate amoebae fauna of the major continents of the world, suggested that N. kivuense was a rare species perhaps endemic to a small, local equatorial region of the African continent. This paper reports its rediscovery from two wetland-conifer forest ecosystems in southern Ontario, Canada (at 44° N Latitude), thus changing dramatically our previous perception of its very restricted global distribution. This has implications for the idea held by many students of biogeography that there is a special category of microscopic protists that contains truly rare species and their rarity, perhaps together with specific habitat requirements and tolerances, limits opportunities for dispersal around the world. The N. kivuense story is a clear example of the dangers of inferring endemism from rarity.
Anatoly Bobrov, Anush Kosakyan
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 289-294
https://doi.org/10.4467/16890027AP.15.024.3538A new species, Porosia paracarinata, is described from mountain forest litter, Bijodaira, Japan. This is the second species in the genus Porosia; until now, the genus was monospecific with the type speciesPorosia bigibbosa. P. paracarinata sp. nov. is distinguished from P. bigibbosa by the presence of a wide lateral keel. Test ultrastructure of P. paracarinata sp. nov. was documented using light and scanning electron microscopy. Morphometric analyses showed that this species is only slightly variable. The main morphological variability is due to the size of the lateral keel, which can vary from very wide (13.13 μm) to very narrow (3.75 μm). Ecological notes and morphological comparisons between P. paracarinataand other closely related species are discussed. The taxonomic concept of previously monospecific genus Porosia is expended.
Yuma Sato, Takaaki Muto, Yoshinari Endo, Toshimasa Kobayashi, Nobuyuki Nakano, Hiroyasu Sato, Goh Nishitani, Waka Sato-Okoshi
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 295-303
https://doi.org/10.4467/16890027AP.15.025.3539Wakame seaweed is an important aquatic resource in Iwate Prefecture. However, a suctorianEphelota gigantea sometimes causes great damage to wakame culture. Since little is known about the biological characteristics of E. gigantea, its detailed morphology and temporal change of biological characteristics during the 2010 culture season were investigated. Scanning electron microscope observations showed that E. gigantea had different striation patterns on the stalk; there was a swell made of cement by which the stalk was attached to wakame firmly; and the buds had cilia arranged in concentric circles about a ring in the center of the ventral side. A suctorian parasite was found to infect E. gigantea, and the infection seemed to have decreased drastically the attached density of E. gigantea on wakame. Cell size of parasite-infected E. gigantea individuals was larger than that of uninfected individuals, probably because larger E. gigantea has larger surface area for attachment of the parasite. Cyst formation or conjugating individuals were not observed.
Yuanjun Zhao, Saleh A. Al-Farraj, Khaled A. S. Al-Rasheid, Weibo Song
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 305-323
https://doi.org/10.4467/16890027AP.15.026.3540Ten new species of myxosporeans found from marine fishes were collected from coastal waters off the Yellow Sea in China: Sphaerospora sebasta sp. n. coelozoic in the gall bladder of Sebastes schlegeli, Ceratomyxa hemitriptera sp. n. coelozoic in the gall bladder of Hemitripterus villosus,Ceratomyxa kareus sp. n. coelozoic in the gall bladders of Kareius bicoloratus and Zebrias zebra,Ceratomyxa lateolabrax sp. n. and Ceratomyxa lomi sp. n. coelozoic in the gall bladder ofLateolabrax japonicus, Ceratomyxa qingdaoensis sp. n. coelozoic in the urinary bladder ofArgyrosomus argentatus, Ceratomyxa saurida sp. n. coelozoic in the gall bladder of Saurida elongata, Ceratomyxa sebastisca sp. n. coelozoic in the gall bladder of Sebastiscus sp., Ceratomyxa simplex sp. n. coelozoic in the gall bladder of Chirolophis japonicus and Ceratomyxa triacantha sp. n. coelozoic in the gall bladder and bile of Triacanthus brevirostris. All those forms were described in a book chapter cited as “known forms” several years ago, but have never been formally established as new taxa which are thus officially reported here. The present contribution only provided the morphology and geographic distribution of these organisms.
Weibo Zheng, Feng Gao, Alan Warren
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 325-330
https://doi.org/10.4467/16890027AP.15.027.3541Uronema marinum is a cosmopolitan marine ciliate. It is a facultative parasite and the main causative agent of outbreaks of scuticociliatosis in aquaculture fish. This study reports a method for the axenic cultivation of U. marinum in high densities in an artificial medium comprising proteose peptone, glucose and yeast extract powder as its basic components. The absence of bacteria in the cultures was confirmed by fluorescence microscopy of DAPI-stained samples and the failure to recover bacterial SSU-rDNA using standard PCR methods. Using this axenic medium, a maximum cell density of 420,000 ciliate cells/ml was achieved, which is significantly higher than in cultures using living bacteria as food or in other axenic media reported previously. This method for high-density axenic cultivation of U. marinum should facilitate future research on this economically important facultative fish parasite.
Nicholas Bock, O. Roger Anderson
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 265-273
https://doi.org/10.4467/16890027AP.15.021.3535Lichens are widely recognized as important examples of a fungal-algal or fungal-cyanophyte symbiosis; and in some cases they are a major food source for some animal grazers such as caribou (Rangifer tarandus), especially in the Arctic during winter. However, relatively little is known about the ecology of their co-associated bacterial and protistan communities. This is one of the first reports of an analysis of microbial communities associated with rock-dwelling foliose lichens (Flavoparmeliasp.), including a more detailed analysis of the microbial communities associated with segments of the shield-like, radially arranged lobes. Samples were taken from lichens on granite boulders beneath an oak and maple tree stand on the Lamont-Doherty Earth Observatory Campus, Palisades, N.Y. The bacteria and protist members of the lichen associated microbial communities are comparable to recently reported associations for foliose lichens growing on tree bark at the same locale, including the presence of large myxomycete plasmodial amebas, heterotrophic nanoflagellates, and naked and testate amebas. To obtain evidence of possible differences in the microecology of different portions of each radial lobe, three segments of the radial lobe in the shield-like lichen were sampled: 1) inner, more mature, central segment; 2) middle section linking the central and peripheral segments; and 3) outer, peripheral, usually broader, less closely attached segment. The mean densities (number/g) and biomasses (µg/g) of bacteria and heterotrophic nanoflagellates were highest in the older central segment and lowest in the peripheral segment of the radial lobes, especially when expressed on moist weight basis. Large myxomycete plasmodial amebas were typically located in the outermost segment of the radial lobe. The proportion of vannellid amebas (Vannella spp. and Cochliopodium spp.) were significantly more abundant in the samples of the inner lobes compared to non-vannellid amebas that were more prevalent in the outer lobes. The outer segment of the thallus lobe was typically more spongiose and absorbed more water per unit weight (based on a wet/dry-weight ratio) than the innermost segment. In general, patterns of densities and taxonomic composition of bacteria and eukaryotic microbes intergraded from the inner most segment to the outer part of each lobe – indicating a possible microecological gradient, coincident with the age-related and morphological radial gradations of the lobe. Overall, the evidence shows that the radial variation in the morphology and age-related variables of the three lobe segments may affect the microenvironment of the lobe segments and hence influence the organization of the microbial communities within each segment.
Helge Abildhauge Thomsen, Jette Buch Østergaard, Lluïsa Cros
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 275-281
https://doi.org/10.4467/16890027AP.15.022.3536It has been known for some time that the distinctive polar weakly calcified coccolithophores are also present in samples from lower latitudes. While polar species may actually have a geographic range that vastly extends beyond the polar realms, it is often the case that the warm water regions contribute species that can be allocated to genera previously described based on polar material. We are currently in the process of formally dealing with the warm water species diversity affiliated with the family Papposphaeraceae. In this paper we describe a new genus and species Ventimolina stellata based on material from the Andaman Sea (type locality) and the NW Mediterranean.
Kenneth H. Nicholls
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 283-288
https://doi.org/10.4467/16890027AP.15.023.3537In 1961, the testate amoeba Nebela kivuense Gauthier-Lièvre et Thomas, 1961 was described for the first and only time from an area near Lake Edward in the Democratic Republic of the Congo (at 0.002° N Latitude). The lack of recent reports of this species, despite exhaustive surveys of the testate amoebae fauna of the major continents of the world, suggested that N. kivuense was a rare species perhaps endemic to a small, local equatorial region of the African continent. This paper reports its rediscovery from two wetland-conifer forest ecosystems in southern Ontario, Canada (at 44° N Latitude), thus changing dramatically our previous perception of its very restricted global distribution. This has implications for the idea held by many students of biogeography that there is a special category of microscopic protists that contains truly rare species and their rarity, perhaps together with specific habitat requirements and tolerances, limits opportunities for dispersal around the world. The N. kivuense story is a clear example of the dangers of inferring endemism from rarity.
Anatoly Bobrov, Anush Kosakyan
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 289-294
https://doi.org/10.4467/16890027AP.15.024.3538A new species, Porosia paracarinata, is described from mountain forest litter, Bijodaira, Japan. This is the second species in the genus Porosia; until now, the genus was monospecific with the type speciesPorosia bigibbosa. P. paracarinata sp. nov. is distinguished from P. bigibbosa by the presence of a wide lateral keel. Test ultrastructure of P. paracarinata sp. nov. was documented using light and scanning electron microscopy. Morphometric analyses showed that this species is only slightly variable. The main morphological variability is due to the size of the lateral keel, which can vary from very wide (13.13 μm) to very narrow (3.75 μm). Ecological notes and morphological comparisons between P. paracarinataand other closely related species are discussed. The taxonomic concept of previously monospecific genus Porosia is expended.
Yuma Sato, Takaaki Muto, Yoshinari Endo, Toshimasa Kobayashi, Nobuyuki Nakano, Hiroyasu Sato, Goh Nishitani, Waka Sato-Okoshi
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 295-303
https://doi.org/10.4467/16890027AP.15.025.3539Wakame seaweed is an important aquatic resource in Iwate Prefecture. However, a suctorianEphelota gigantea sometimes causes great damage to wakame culture. Since little is known about the biological characteristics of E. gigantea, its detailed morphology and temporal change of biological characteristics during the 2010 culture season were investigated. Scanning electron microscope observations showed that E. gigantea had different striation patterns on the stalk; there was a swell made of cement by which the stalk was attached to wakame firmly; and the buds had cilia arranged in concentric circles about a ring in the center of the ventral side. A suctorian parasite was found to infect E. gigantea, and the infection seemed to have decreased drastically the attached density of E. gigantea on wakame. Cell size of parasite-infected E. gigantea individuals was larger than that of uninfected individuals, probably because larger E. gigantea has larger surface area for attachment of the parasite. Cyst formation or conjugating individuals were not observed.
Yuanjun Zhao, Saleh A. Al-Farraj, Khaled A. S. Al-Rasheid, Weibo Song
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 305-323
https://doi.org/10.4467/16890027AP.15.026.3540Ten new species of myxosporeans found from marine fishes were collected from coastal waters off the Yellow Sea in China: Sphaerospora sebasta sp. n. coelozoic in the gall bladder of Sebastes schlegeli, Ceratomyxa hemitriptera sp. n. coelozoic in the gall bladder of Hemitripterus villosus,Ceratomyxa kareus sp. n. coelozoic in the gall bladders of Kareius bicoloratus and Zebrias zebra,Ceratomyxa lateolabrax sp. n. and Ceratomyxa lomi sp. n. coelozoic in the gall bladder ofLateolabrax japonicus, Ceratomyxa qingdaoensis sp. n. coelozoic in the urinary bladder ofArgyrosomus argentatus, Ceratomyxa saurida sp. n. coelozoic in the gall bladder of Saurida elongata, Ceratomyxa sebastisca sp. n. coelozoic in the gall bladder of Sebastiscus sp., Ceratomyxa simplex sp. n. coelozoic in the gall bladder of Chirolophis japonicus and Ceratomyxa triacantha sp. n. coelozoic in the gall bladder and bile of Triacanthus brevirostris. All those forms were described in a book chapter cited as “known forms” several years ago, but have never been formally established as new taxa which are thus officially reported here. The present contribution only provided the morphology and geographic distribution of these organisms.
Weibo Zheng, Feng Gao, Alan Warren
Acta Protozoologica, Volume 54, Issue 4, 2015, pp. 325-330
https://doi.org/10.4467/16890027AP.15.027.3541Uronema marinum is a cosmopolitan marine ciliate. It is a facultative parasite and the main causative agent of outbreaks of scuticociliatosis in aquaculture fish. This study reports a method for the axenic cultivation of U. marinum in high densities in an artificial medium comprising proteose peptone, glucose and yeast extract powder as its basic components. The absence of bacteria in the cultures was confirmed by fluorescence microscopy of DAPI-stained samples and the failure to recover bacterial SSU-rDNA using standard PCR methods. Using this axenic medium, a maximum cell density of 420,000 ciliate cells/ml was achieved, which is significantly higher than in cultures using living bacteria as food or in other axenic media reported previously. This method for high-density axenic cultivation of U. marinum should facilitate future research on this economically important facultative fish parasite.
Publication date: 09.07.2015
Editor-in-Chief: Krzysztof Wiąckowski
Helge Abildhauge Thomsen, Jette Buch Østergaard
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 155-169
https://doi.org/10.4467/16890027AP.15.013.3210Coccolithophorid samples from arctic and antartic regions have been examined for an update on species morphology, life history aspects and biogeography for the coccolithophorid genera Ericiolus and Quaternariella and two other genera here described as new. Mercedesia gen. nov. comprises three new species, M. aspiphora sp. nov. from both polar regions, the arctic M. multistellata sp. nov. and the Antarctic M. pusilla sp. nov. The genus is characterized by its monomorphic nannoliths that are shaped like three-armed stars. The new arctic monospecific genus Porsildia gen. nov. is established for the heterococcolith-bearing species P. acerviphora sp. nov. Combination cells, from the arctic region, bearing holococcoliths of Quaternariella obscura and previously undescribed heterococcoliths, with a Papposphaeracean affinity, are described here for the first time.
Mingjian LIU, Yangbo Fan, Miao Miao, Xiaozhong Hu, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj, Honggang Ma
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 171-182
https://doi.org/10.4467/16890027AP.15.014.3211This paper investigates the morphology and morphogenesis during binary fission of a Chinese population of Euplotes amieti Dragesco, 1970, a fresh water form which has previously not been well defined. This organism is morphologically very similar to the well-known Euplotes eurystomus but differs from the latter both in the number of dorsal kineties and the molecular data. According to the information obtained, it is characterized by a combination of features including nine frontoventral cirri, ca. 60 membranelles, 12–15 dorsal kineties, a macronucleus in the shape of the number 3, and a ‘double-eurystomus’ type of silverline system. Its morphogenesis proceeds broadly in the same pattern as in its congeners. In this study, the SSU rRNA gene was sequenced for the first time, and phylogenetic analyses indicated that it is closely related to the eurystomus-aediculatus-woodruffi- complex. Considering the extreme similarities in morphology between E. amieti and E.eurystomus, we believe that the four sequences (four isolates) under the name of Euplotes eurystomus (No. FR873716; FR873717; EF193250; AJ310491 deposited in GenBank) are very likely from misidentified material; that is, they represent different populations of Euplotes amieti.
Yuan Xu, Lifang LI, Xinpeng Fan, Hongbo Pan, Fukang Gu, Saleh A. Al-Farraj
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 183-193
https://doi.org/10.4467/16890027AP.15.015.3212Two oxytrichids Architricha indica Gupta et al., 2006 and Pleurotricha curdsi (Shi et al. 2002) Gupta et al., 2003 collected in East China, were studied using live observation and the silver staining method. The description and morphometric characterization of the new populations were supplied. The Shanghai population of A. indica differs from the Indian population in the number of cirri in the third right marginal row (average of 16.8 vs. 21.1). The Shanghai population of P. curdsicorresponds well with the Indian population, but it differs from the other Chinese population in the number of right marginal rows (two vs. three). The early process of reorganization of A. indica was studied, and a difference on the formation of anlage V was found compared to the original report. The small subunit rRNA genes of both species were sequenced for the first time. The phylogenetic analyses based on SSU rRNA gene sequence data revealed that Architricha is sister to the assemblage of Pseudouroleptus caudatus and two Strongylidium, while P. curdsi clusters with its congener P. lanceolata and is located in Stylonychinae.
Kuidong Xu, Weibo Song, Alan Warren
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 195-208
https://doi.org/10.4467/16890027AP.15.016.3213The morphology and taxonomy of two new and two poorly known ciliate species of Ancistrum, found in the mantle cavity (mainly on gills) of marine molluscs from culture beds and pools along the Chinese coast of the Yellow Sea, were investigated using living observation and silver impregnation. Ancistrum haliotis n. sp. was isolated from the abalone Haliotis discus hannai Ino, A. crassum Fenchel, 1965 from the purple clam Saxidomus purpuratus (Sowerby), A. acutum n. sp. from the surf clam Mactra veneriformis Reeve, and A. japonicum Uyemura, 1937 from both the venus clam Cyclina sinensis (Gmelin) and from Dosinia japonica (Reeve). Ancistrum haliotis differs from its most similar relative A. mytili (Quennerstedt, 1867) by the body outline (anterior portion narrower vs. wider than the posterior portion), the macronuclear shape (broadly ellipsoidal vs. reniform or sausage-like), and by having fewer somatic kineties (28–32 vs. usually more than >40). Ancistrum crassum is characterized by the naked area at the apical end of the cell, the relatively short buccal field occupying about two thirds of the body length, and the posterior-dorsal cone-shaped prolongation. Ancistrum acutum n. sp. and A. japonicum are almost identical in morphometry, but differ distinctly in the live morphology (anterior end pointed and posterior end rounded vs. anterior end narrowly rounded and posterior-dorsal end protruded) and ciliary pattern (all right-side kineties extend to posterior body end vs. all right-side kineties excluding somatic kinety 1 distinctly shortened posteriad, forming a glabrous zone). We neotypify Ancistrum japonicum and discuss the taxonomic status of the four species. Based on an evaluation of all nominal species of Ancistrum and Ancistrumina, we recognize nine valid species of Ancistrum and provide a tabular guide to their identification. Fenchelia Raabe, 1970 is regarded as a junior synonym of Ancistrum Maupas, 1883. We synonymize Ancistrumina nucellae Khan, 1970 with Ancistrum japonicum Uyemura, 1937 and Ancistrum edajimanum Oishi, 1978 with A. crassum Fenchel, 1965.
Arturo González-Robles, Bibiana Chávez-Munguía, Lizbeth Salazar‑Villatoro, Anel Lagunes-Guillén, Verónica Ivonne Hernández-Ramírez, Patricia Talamás-Rohana, Adolfo Martínez-Palomo
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 209-218
https://doi.org/10.4467/16890027AP.15.017.3214Using ultrastructural cytochemical techniques we have found differences in the distribution of surface coat components between the invasive protozoan parasite Entamoeba histolytica and the non-invasive Entamoeba dispar. Carbohydrate-containing components and anionic sites in the cell surface of both species were detected by staining with ruthenium red and cationized ferritin, respectively. Ruthenium red staining revealed a thicker surface coat in E. histolytica trophozoites, whereas trophozoites of E. dispar showed a higher concentration of cationized ferritin particles on its surface. Mannose or glucose residues were found at the plasma membrane of both parasites treated with Concanavalin A (Con A)-peroxidase; the surface reaction product was more evident in E. dispar, compared with E. histolytica. Con A rapidly produced surface caps in E. histolytica trophozoites, whereas E. dispar showed a much less efficient mobilization of surface Con A receptors. Agglutination with Con A produced much larger clumps in E. histolytica in comparison with E. dispar. In turn, biotinylation assays revealed striking differences in the composition of surface membrane proteins in both amebic species. Overall, these results further emphasize the phenotypic differences between these two common parasites of the human intestinal tract, once considered to be the same protozoan.
Rudolf Wegensteiner, Cezary Tkaczuk, Stanisław Bałazy, Sonja Griesser, Marie‑Ange Rouffaud, Andrea Stradner, Bernhardt M. Steinwender, Herbert Hager, Bernard Papierok
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 219-232
https://doi.org/10.4467/16890027AP.15.018.3215Occurrence of pathogens in four important forest pest insect species, Ips typographus, Ips sexdentatus, Hylobius abietis and Hylobius pinastri, from Austria, Poland and France was investigated in 2006–2008. Insects were collected from 46 sampling sites. In total 5,634 living adult beetles were dissected. Some dead adults and some very few dead larvae were inspected for fungal infection. Eight pathogen species (Ips typographus entomopoxvirus, Gregarina typographi, Mattesia sp.,Chytridiopsis typographi, Unikaryon montanum, Beauveria bassiana, Beauveria caledonica and Isaria farinosa) were found in I. typographus from the three countries. Four pathogen species were found in I. sexdentatus from Austria and France (Gregarina cf. typographi, Metschnikowia cf. typographi, B. bassiana and B. caledonica). Five pathogen species were found in H. abietis from Austria and Poland (Gregarina hylobii, Ophryocystis hylobii, Nosema hylobii, B. bassiana and B. brongniartii) and two in H. pinastri from Poland (G. hylobii and O. hylobii). Some of the pathogen species were found for the first time in one of the three countries or are reported for the first time in one of the investigated beetle species. Differences in occurrence and geographical distribution of these pathogens are discussed with regard to their respective apparent host spectrum and possible ecological requirements.
Nadia Ramadan, Samia Fawzy, Medhat Ali, Ahmed Nigm
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 233-240
https://doi.org/10.4467/16890027AP.15.019.3216A new acephaline gregarine is described from the earthworms Pheretima californica and Pheretima elongata. The gregarine was either embedded in the pharyngeal glandular tissue or found free in the coelomic fluid around the pharyngeal region in front of the crop. Adult trophozoites measured 48–65 µm in diameter and are mostly active with a wavy pellicle. Heterogeneity in the endoplasm of active trophozoites was observed. Gametocysts measured 56–81 µm in diameter, with a characteristic thick cyst wall. Navicular sporocysts measured 5.8 ± 0.2 × 3.5 ± 0.4 µm, with small truncate plugs.
Timur G. Simdyanov, Andrei Y. Diakin, Vladimir V. Aleoshin
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 241-262
https://doi.org/10.4467/16890027AP.15.020.321718S rRNA gene sequences (SSU rDNA) in gregarines are problematic for phylogenetic analysis, mainly due to artifacts related to long branch attraction (LBA). In this study, we sequenced 18S rRNA (SSU rRNA), 5.8S rRNA, and 28S rRNA (LSU rRNA) genes of two gregarine species from crustacean hosts (gregarine superfamily Cephaloidophoroidea): Cephaloidophora cf. communis from a marine cirripedian Balanus balanus (White Sea), and Heliospora cf. longissima from the freshwater amphipods, Eulimnogammarus verrucosus and E. vittatus (Lake Baikal). Phylogenetic analyses of SSU rDNA sequences failed to produce a robust tree topology, for a limited taxon sample (31 operational taxonomic units (OTU), based on 1,604 sites), while LSU (2,869 sites), and concatenated dataset based on SSU, 5.8S, and LSU (4,627 sites) produced more consistent tree topologies for the same taxon sample. Analyses testing for LBA-influence were negative, therefore we suggested that the main reason of the failed topologies in SSU rDNA analyses is insufficient data (insufficient taxon sampling and limited molecular data), rather than LBA. Possible advantages of Bayesian analyses, compared to Maximum Likelihood, and usage of LSU rDNA within the context of apicomplexan phylogenetics were discussed. One of the advantages of LSU is likely its lower rate of evolution in long-branching apicomplexans (e.g., gregarines), relative to other (non-long-branching) apicomplexans, compared to SSU rDNA. Ultrastructure of the epicytic folds was studied. There are 3 to 5 apical arcs (also known as rippled dense structures) and 2 to 5 apical filaments in the tops of the folds. This small number of the apical structures fits into morphological diversity of the epicyte in other Cephaloidophoroidea, but this is not a synapomorphy of the group because this was also detected in several unrelated gregarines. C. cf. communis was found to contain a septum between the epimerite and the protomerite, which has not been reported in other gregarines. More exact terminology, which takes into account number of body sections and septa, is proposed for morphological descriptions of trophozoites and free mature gamonts of gregarines. In accordance with this, C. cf. communis gamonts are tricystid and biseptate, whereas H. cf. longissima gamonts are tricystid and uniseptate, similar to other eugregarines.
Helge Abildhauge Thomsen, Jette Buch Østergaard
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 155-169
https://doi.org/10.4467/16890027AP.15.013.3210Coccolithophorid samples from arctic and antartic regions have been examined for an update on species morphology, life history aspects and biogeography for the coccolithophorid genera Ericiolus and Quaternariella and two other genera here described as new. Mercedesia gen. nov. comprises three new species, M. aspiphora sp. nov. from both polar regions, the arctic M. multistellata sp. nov. and the Antarctic M. pusilla sp. nov. The genus is characterized by its monomorphic nannoliths that are shaped like three-armed stars. The new arctic monospecific genus Porsildia gen. nov. is established for the heterococcolith-bearing species P. acerviphora sp. nov. Combination cells, from the arctic region, bearing holococcoliths of Quaternariella obscura and previously undescribed heterococcoliths, with a Papposphaeracean affinity, are described here for the first time.
Mingjian LIU, Yangbo Fan, Miao Miao, Xiaozhong Hu, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj, Honggang Ma
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 171-182
https://doi.org/10.4467/16890027AP.15.014.3211This paper investigates the morphology and morphogenesis during binary fission of a Chinese population of Euplotes amieti Dragesco, 1970, a fresh water form which has previously not been well defined. This organism is morphologically very similar to the well-known Euplotes eurystomus but differs from the latter both in the number of dorsal kineties and the molecular data. According to the information obtained, it is characterized by a combination of features including nine frontoventral cirri, ca. 60 membranelles, 12–15 dorsal kineties, a macronucleus in the shape of the number 3, and a ‘double-eurystomus’ type of silverline system. Its morphogenesis proceeds broadly in the same pattern as in its congeners. In this study, the SSU rRNA gene was sequenced for the first time, and phylogenetic analyses indicated that it is closely related to the eurystomus-aediculatus-woodruffi- complex. Considering the extreme similarities in morphology between E. amieti and E.eurystomus, we believe that the four sequences (four isolates) under the name of Euplotes eurystomus (No. FR873716; FR873717; EF193250; AJ310491 deposited in GenBank) are very likely from misidentified material; that is, they represent different populations of Euplotes amieti.
Yuan Xu, Lifang LI, Xinpeng Fan, Hongbo Pan, Fukang Gu, Saleh A. Al-Farraj
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 183-193
https://doi.org/10.4467/16890027AP.15.015.3212Two oxytrichids Architricha indica Gupta et al., 2006 and Pleurotricha curdsi (Shi et al. 2002) Gupta et al., 2003 collected in East China, were studied using live observation and the silver staining method. The description and morphometric characterization of the new populations were supplied. The Shanghai population of A. indica differs from the Indian population in the number of cirri in the third right marginal row (average of 16.8 vs. 21.1). The Shanghai population of P. curdsicorresponds well with the Indian population, but it differs from the other Chinese population in the number of right marginal rows (two vs. three). The early process of reorganization of A. indica was studied, and a difference on the formation of anlage V was found compared to the original report. The small subunit rRNA genes of both species were sequenced for the first time. The phylogenetic analyses based on SSU rRNA gene sequence data revealed that Architricha is sister to the assemblage of Pseudouroleptus caudatus and two Strongylidium, while P. curdsi clusters with its congener P. lanceolata and is located in Stylonychinae.
Kuidong Xu, Weibo Song, Alan Warren
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 195-208
https://doi.org/10.4467/16890027AP.15.016.3213The morphology and taxonomy of two new and two poorly known ciliate species of Ancistrum, found in the mantle cavity (mainly on gills) of marine molluscs from culture beds and pools along the Chinese coast of the Yellow Sea, were investigated using living observation and silver impregnation. Ancistrum haliotis n. sp. was isolated from the abalone Haliotis discus hannai Ino, A. crassum Fenchel, 1965 from the purple clam Saxidomus purpuratus (Sowerby), A. acutum n. sp. from the surf clam Mactra veneriformis Reeve, and A. japonicum Uyemura, 1937 from both the venus clam Cyclina sinensis (Gmelin) and from Dosinia japonica (Reeve). Ancistrum haliotis differs from its most similar relative A. mytili (Quennerstedt, 1867) by the body outline (anterior portion narrower vs. wider than the posterior portion), the macronuclear shape (broadly ellipsoidal vs. reniform or sausage-like), and by having fewer somatic kineties (28–32 vs. usually more than >40). Ancistrum crassum is characterized by the naked area at the apical end of the cell, the relatively short buccal field occupying about two thirds of the body length, and the posterior-dorsal cone-shaped prolongation. Ancistrum acutum n. sp. and A. japonicum are almost identical in morphometry, but differ distinctly in the live morphology (anterior end pointed and posterior end rounded vs. anterior end narrowly rounded and posterior-dorsal end protruded) and ciliary pattern (all right-side kineties extend to posterior body end vs. all right-side kineties excluding somatic kinety 1 distinctly shortened posteriad, forming a glabrous zone). We neotypify Ancistrum japonicum and discuss the taxonomic status of the four species. Based on an evaluation of all nominal species of Ancistrum and Ancistrumina, we recognize nine valid species of Ancistrum and provide a tabular guide to their identification. Fenchelia Raabe, 1970 is regarded as a junior synonym of Ancistrum Maupas, 1883. We synonymize Ancistrumina nucellae Khan, 1970 with Ancistrum japonicum Uyemura, 1937 and Ancistrum edajimanum Oishi, 1978 with A. crassum Fenchel, 1965.
Arturo González-Robles, Bibiana Chávez-Munguía, Lizbeth Salazar‑Villatoro, Anel Lagunes-Guillén, Verónica Ivonne Hernández-Ramírez, Patricia Talamás-Rohana, Adolfo Martínez-Palomo
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 209-218
https://doi.org/10.4467/16890027AP.15.017.3214Using ultrastructural cytochemical techniques we have found differences in the distribution of surface coat components between the invasive protozoan parasite Entamoeba histolytica and the non-invasive Entamoeba dispar. Carbohydrate-containing components and anionic sites in the cell surface of both species were detected by staining with ruthenium red and cationized ferritin, respectively. Ruthenium red staining revealed a thicker surface coat in E. histolytica trophozoites, whereas trophozoites of E. dispar showed a higher concentration of cationized ferritin particles on its surface. Mannose or glucose residues were found at the plasma membrane of both parasites treated with Concanavalin A (Con A)-peroxidase; the surface reaction product was more evident in E. dispar, compared with E. histolytica. Con A rapidly produced surface caps in E. histolytica trophozoites, whereas E. dispar showed a much less efficient mobilization of surface Con A receptors. Agglutination with Con A produced much larger clumps in E. histolytica in comparison with E. dispar. In turn, biotinylation assays revealed striking differences in the composition of surface membrane proteins in both amebic species. Overall, these results further emphasize the phenotypic differences between these two common parasites of the human intestinal tract, once considered to be the same protozoan.
Rudolf Wegensteiner, Cezary Tkaczuk, Stanisław Bałazy, Sonja Griesser, Marie‑Ange Rouffaud, Andrea Stradner, Bernhardt M. Steinwender, Herbert Hager, Bernard Papierok
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 219-232
https://doi.org/10.4467/16890027AP.15.018.3215Occurrence of pathogens in four important forest pest insect species, Ips typographus, Ips sexdentatus, Hylobius abietis and Hylobius pinastri, from Austria, Poland and France was investigated in 2006–2008. Insects were collected from 46 sampling sites. In total 5,634 living adult beetles were dissected. Some dead adults and some very few dead larvae were inspected for fungal infection. Eight pathogen species (Ips typographus entomopoxvirus, Gregarina typographi, Mattesia sp.,Chytridiopsis typographi, Unikaryon montanum, Beauveria bassiana, Beauveria caledonica and Isaria farinosa) were found in I. typographus from the three countries. Four pathogen species were found in I. sexdentatus from Austria and France (Gregarina cf. typographi, Metschnikowia cf. typographi, B. bassiana and B. caledonica). Five pathogen species were found in H. abietis from Austria and Poland (Gregarina hylobii, Ophryocystis hylobii, Nosema hylobii, B. bassiana and B. brongniartii) and two in H. pinastri from Poland (G. hylobii and O. hylobii). Some of the pathogen species were found for the first time in one of the three countries or are reported for the first time in one of the investigated beetle species. Differences in occurrence and geographical distribution of these pathogens are discussed with regard to their respective apparent host spectrum and possible ecological requirements.
Nadia Ramadan, Samia Fawzy, Medhat Ali, Ahmed Nigm
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 233-240
https://doi.org/10.4467/16890027AP.15.019.3216A new acephaline gregarine is described from the earthworms Pheretima californica and Pheretima elongata. The gregarine was either embedded in the pharyngeal glandular tissue or found free in the coelomic fluid around the pharyngeal region in front of the crop. Adult trophozoites measured 48–65 µm in diameter and are mostly active with a wavy pellicle. Heterogeneity in the endoplasm of active trophozoites was observed. Gametocysts measured 56–81 µm in diameter, with a characteristic thick cyst wall. Navicular sporocysts measured 5.8 ± 0.2 × 3.5 ± 0.4 µm, with small truncate plugs.
Timur G. Simdyanov, Andrei Y. Diakin, Vladimir V. Aleoshin
Acta Protozoologica, Volume 54, Issue 3, 2015, pp. 241-262
https://doi.org/10.4467/16890027AP.15.020.321718S rRNA gene sequences (SSU rDNA) in gregarines are problematic for phylogenetic analysis, mainly due to artifacts related to long branch attraction (LBA). In this study, we sequenced 18S rRNA (SSU rRNA), 5.8S rRNA, and 28S rRNA (LSU rRNA) genes of two gregarine species from crustacean hosts (gregarine superfamily Cephaloidophoroidea): Cephaloidophora cf. communis from a marine cirripedian Balanus balanus (White Sea), and Heliospora cf. longissima from the freshwater amphipods, Eulimnogammarus verrucosus and E. vittatus (Lake Baikal). Phylogenetic analyses of SSU rDNA sequences failed to produce a robust tree topology, for a limited taxon sample (31 operational taxonomic units (OTU), based on 1,604 sites), while LSU (2,869 sites), and concatenated dataset based on SSU, 5.8S, and LSU (4,627 sites) produced more consistent tree topologies for the same taxon sample. Analyses testing for LBA-influence were negative, therefore we suggested that the main reason of the failed topologies in SSU rDNA analyses is insufficient data (insufficient taxon sampling and limited molecular data), rather than LBA. Possible advantages of Bayesian analyses, compared to Maximum Likelihood, and usage of LSU rDNA within the context of apicomplexan phylogenetics were discussed. One of the advantages of LSU is likely its lower rate of evolution in long-branching apicomplexans (e.g., gregarines), relative to other (non-long-branching) apicomplexans, compared to SSU rDNA. Ultrastructure of the epicytic folds was studied. There are 3 to 5 apical arcs (also known as rippled dense structures) and 2 to 5 apical filaments in the tops of the folds. This small number of the apical structures fits into morphological diversity of the epicyte in other Cephaloidophoroidea, but this is not a synapomorphy of the group because this was also detected in several unrelated gregarines. C. cf. communis was found to contain a septum between the epimerite and the protomerite, which has not been reported in other gregarines. More exact terminology, which takes into account number of body sections and septa, is proposed for morphological descriptions of trophozoites and free mature gamonts of gregarines. In accordance with this, C. cf. communis gamonts are tricystid and biseptate, whereas H. cf. longissima gamonts are tricystid and uniseptate, similar to other eugregarines.
Publication date: 01.01.2015
Editor-in-Chief: Krzysztof Wiąckowski
Helge Abildhauge Thomsen, Jette Buch Østergaard
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 85-96
https://doi.org/10.4467/16890027AP.15.007.2732Xinpeng Fan, Yuan Xu, Fukang Gu, Jiqiu Li, Saleh A. Al-Farraj, Khaled A. S. Al-Rasheid, Xiaozhong Hu
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 97-106
https://doi.org/10.4467/16890027AP.15.008.2733During faunistic studies of ciliates in coastal waters of Daya Bay and Bohai Bay, China, two previously unknown ciliates were discovered and investigated using standard taxonomic methods. Morphological comparative analyses revealed that they represent two novel species in the genusChaenea. Chaenea paucistriata spec. nov. can be distinguished from its congeners by the following traits: body length in vivo about 180–250 µm; eight somatic kineties; dorsal brush rows 1–4 consisting of three, five, seven, and two dikinetids, respectively; rod-like extrusomes, 8 µm long; 63–94 macronuclei; cortical granules minute and colourless. Chaenea sinica spec. nov. differs from its congeners in having: body length in vivo about 140–240 µm; 17–21 somatic kineties; dorsal brush rows 1–4 consisting of 3–7, 10 or 11, 11–13, and 3–6 dikinetids, respectively; rod-like extrusomes about 6–8 µm long; 71–164 macronuclei. A key is presented to assist the identification of allChaenea species.
Xiaozhong Hu, Yasushi Kusuoka
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 107-122
https://doi.org/10.4467/16890027AP.15.009.2734Two oxytrichid freshwater ciliates, Apoamphisiella tihanyiensis (Gellért and Tamás, 1958) Foissner, 1997 and Notohymena australis (Foissner and O’Donoghue, 1990) Berger, 1999, were recorded for the first time in Lake Biwa, a 4-million-year-old lake located at the Shiga Prefecture in Japan. Their morphology was investigated based on observations of live and protargol-impregnated material. Based on the present observation and previous descriptions, A. tihanyiensis is characterized by having an elliptical body shape, yellowish cortical granules, two long frontoventral rows, enlarged frontal and transverse cirri, highly variable numbers of frontoventral, and postoral ventral cirri, and six to 11 caudal cirri arranged in three short rows. New data confirm the presence of pretransverse ventral cirri in this species. Morphologically, N. australis differs from its congeners in having the following combination of characters: greenish cortical granules, the cirrus V/2 located slight anterior to the leftmost transverse cirrus, dorsal kinety 3 almost as long as body, and seven to 10 caudal cirri arranged in three short rows. Morphogenesis in N. australis shows the same pattern as in N. apoaustralis but differs from that of other congeners in the origin of oral primordium and the formation of more than just three caudal cirri.
Seok Won Jang, Peter Vďačný, Shahed Uddin Ahmed Shazib, Mann Kyoon Shin
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 123-135
https://doi.org/10.4467/16890027AP.15.010.2735We isolated a relatively unknown haptorian ciliate, Trachelophyllum brachypharynx, in brackish water from the mouth of the Taehwa River, South Korea. The morphology of this isolate was studied using in vivo observation and protargol impregnation, and its evolutionary history was revealed by phylogenetic analysis of the 18S rRNA gene. The main features of T. brachypharynx include (i) a very narrowly fusiform and slightly contractile body about 380 × 40 μm in size; (ii) two ellipsoidal macronuclear nodules typically connected by a fine strand; (iii) a single terminal contractile vacuole; (iv) filiform extrusomes that are typically 30 µm long; (v) an average of 24 ciliary rows, with two of them anteriorly differentiated into an isostichad dikinetidal dorsal brush; and (vi) hat-shaped lepidosomes. Based on the 18S rRNA gene phylogeny, T. brachypharynx clustered together withTrachelophyllum sp. within the order Spathidiida. Furthermore, phylogenetic trees and networks indicate some members from the genera Enchelyodon and Spathidium as the nearest relatives of trachelophyllids. Therefore, based on the present molecular and comparative-morphological analyses, we suggested a hypothesis explaining how trachelophyllids may have evolved from a spathidiid-like ancestor via an enchelyodonid-like stage.
Chanawat Tuntiwaranuruk, Jantanee Noppharatarphakul, Jirat Boonmameepool, E. Suchart Upatham
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 137-142
https://doi.org/10.4467/16890027AP.15.011.2736Anna Lazzaro, Ute Risse-Buhl, Robert Brankatschk
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 143-154
https://doi.org/10.4467/16890027AP.15.012.2737Helge Abildhauge Thomsen, Jette Buch Østergaard
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 85-96
https://doi.org/10.4467/16890027AP.15.007.2732Xinpeng Fan, Yuan Xu, Fukang Gu, Jiqiu Li, Saleh A. Al-Farraj, Khaled A. S. Al-Rasheid, Xiaozhong Hu
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 97-106
https://doi.org/10.4467/16890027AP.15.008.2733During faunistic studies of ciliates in coastal waters of Daya Bay and Bohai Bay, China, two previously unknown ciliates were discovered and investigated using standard taxonomic methods. Morphological comparative analyses revealed that they represent two novel species in the genusChaenea. Chaenea paucistriata spec. nov. can be distinguished from its congeners by the following traits: body length in vivo about 180–250 µm; eight somatic kineties; dorsal brush rows 1–4 consisting of three, five, seven, and two dikinetids, respectively; rod-like extrusomes, 8 µm long; 63–94 macronuclei; cortical granules minute and colourless. Chaenea sinica spec. nov. differs from its congeners in having: body length in vivo about 140–240 µm; 17–21 somatic kineties; dorsal brush rows 1–4 consisting of 3–7, 10 or 11, 11–13, and 3–6 dikinetids, respectively; rod-like extrusomes about 6–8 µm long; 71–164 macronuclei. A key is presented to assist the identification of allChaenea species.
Xiaozhong Hu, Yasushi Kusuoka
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 107-122
https://doi.org/10.4467/16890027AP.15.009.2734Two oxytrichid freshwater ciliates, Apoamphisiella tihanyiensis (Gellért and Tamás, 1958) Foissner, 1997 and Notohymena australis (Foissner and O’Donoghue, 1990) Berger, 1999, were recorded for the first time in Lake Biwa, a 4-million-year-old lake located at the Shiga Prefecture in Japan. Their morphology was investigated based on observations of live and protargol-impregnated material. Based on the present observation and previous descriptions, A. tihanyiensis is characterized by having an elliptical body shape, yellowish cortical granules, two long frontoventral rows, enlarged frontal and transverse cirri, highly variable numbers of frontoventral, and postoral ventral cirri, and six to 11 caudal cirri arranged in three short rows. New data confirm the presence of pretransverse ventral cirri in this species. Morphologically, N. australis differs from its congeners in having the following combination of characters: greenish cortical granules, the cirrus V/2 located slight anterior to the leftmost transverse cirrus, dorsal kinety 3 almost as long as body, and seven to 10 caudal cirri arranged in three short rows. Morphogenesis in N. australis shows the same pattern as in N. apoaustralis but differs from that of other congeners in the origin of oral primordium and the formation of more than just three caudal cirri.
Seok Won Jang, Peter Vďačný, Shahed Uddin Ahmed Shazib, Mann Kyoon Shin
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 123-135
https://doi.org/10.4467/16890027AP.15.010.2735We isolated a relatively unknown haptorian ciliate, Trachelophyllum brachypharynx, in brackish water from the mouth of the Taehwa River, South Korea. The morphology of this isolate was studied using in vivo observation and protargol impregnation, and its evolutionary history was revealed by phylogenetic analysis of the 18S rRNA gene. The main features of T. brachypharynx include (i) a very narrowly fusiform and slightly contractile body about 380 × 40 μm in size; (ii) two ellipsoidal macronuclear nodules typically connected by a fine strand; (iii) a single terminal contractile vacuole; (iv) filiform extrusomes that are typically 30 µm long; (v) an average of 24 ciliary rows, with two of them anteriorly differentiated into an isostichad dikinetidal dorsal brush; and (vi) hat-shaped lepidosomes. Based on the 18S rRNA gene phylogeny, T. brachypharynx clustered together withTrachelophyllum sp. within the order Spathidiida. Furthermore, phylogenetic trees and networks indicate some members from the genera Enchelyodon and Spathidium as the nearest relatives of trachelophyllids. Therefore, based on the present molecular and comparative-morphological analyses, we suggested a hypothesis explaining how trachelophyllids may have evolved from a spathidiid-like ancestor via an enchelyodonid-like stage.
Chanawat Tuntiwaranuruk, Jantanee Noppharatarphakul, Jirat Boonmameepool, E. Suchart Upatham
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 137-142
https://doi.org/10.4467/16890027AP.15.011.2736Anna Lazzaro, Ute Risse-Buhl, Robert Brankatschk
Acta Protozoologica, Volume 54, Issue 2, 2015, pp. 143-154
https://doi.org/10.4467/16890027AP.15.012.2737Publication date: 30.10.2014
Editor-in-Chief: Krzysztof Wiąckowski
Anatoly Bobrov, David M. Wilkinson , Yangmin QIN
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 1-8
https://doi.org/10.4467/16890027AP.15.001.2188The extent to which free-living microorganisms show cosmopolitan distributions has been a contentious aspect of microbial ecology over the last few decades. Testate amoebae are a group of free living protists that can provide important evidence for the nature of the biogeography of microorganisms because there are relatively good data on the distribution of their morpho-species (compared to many other microbial groups). Many testate amoebae appear to exhibit ubiquitous distributions, while some taxa have proven to be endemic to limited regions. The genusHoogenraadia (Gauthier-Lièvre and Thomas 1958) is of particular interest in this context as it appears to be restricted to relatively low latitudes. There are six described species of the genus: H. africana Gauthier-Lièvre and Thomas 1958, H. asiatica Wang and Min 1987, H. cryptostoma Gauthier-Lièvre and Thomas 1958, H. humicola Bonnet 1976, H. ovata Bonnet 1976, and H. sylvatica Vucetich 1974. However, information on these taxa is scattered through a number of different papers – here we provide a summary of what is known about the taxonomy and ecology of this genus. We also reinterpret recent new records of putative H. africana from China (suggesting this identification is not reliable). As an example of a protist taxon largely restricted to the tropics this genus is of particular interest in microbial biogeography and this paper discusses its morphology, ecology and distribution in this context.
Peter Vďačný, Mann Kyoon Shin, Ji Hye Kim, Seok Won Jang, Shahed Uddin Ahmed Shazib, Ľubomír Rajter
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 9-29
https://doi.org/10.4467/16890027AP.15.002.2189Pleurostomatids are raptorial ciliates that form a very distinct group within the Haptoria. Traditionally, the order Pleurostomatida was divided into two families: the Amphileptidae with two perioral kineties and a suture formed by the right side ciliary rows, and the Litonotidae with three perioral kineties and without suture. However, molecular phylogenies depicted the “traditional” Amphileptidae as a paraphyletic assemblage nesting also the Litonotidae. To overcome this problem we have analyzed genealogy of pleurostomatids using morphological data and 18S rRNA gene sequences, including newly sequenced genera Acineria and Kentrophyllum. Specifically, we have combined a morphological and molecular approach and have used also some other phylogenetic tools such as phylogenetic networks, split spectrum analysis, quartet mapping as well as the likelihood method of tracing history of morphological characters. These analyses show that: (1) there are not two but three distinct pleurostomatid lineages – Epiphyllidae fam. nov., Amphileptidae and Litonotidae; (2) epiphyllids (Epiphyllum + Kentrophyllum) represent a basal pleurostomatid group which is defined by two perioral kineties, by the presence of a suture on both the right and the left side of the body, by the loss of the oral bulge extrusomes, and by the extrusome fringe extending all around the body except for the oral region; (3) the families Amphileptidae and Litonotidae are monophyletic each, and represent sister groups; (4) Acineria belongs to the Litonotidae, as already indicated by morphological data; (5) Loxophyllum is a monophyletic and crown genus of the Litonotidae; and (6) Litonotus is paraphyletic, which could be very likely caused by a rapid radiation event that did not allow primary nucleotide homologies to be fixed.
Xuming Pan, Feng Gao, Miao Miao, Khaled A. S. Al-Rasheid, Honggang Ma, Xinpeng Fan, Jie Huang
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 31-43
https://doi.org/10.4467/16890027AP.15.003.2190The morphology and infraciliature of four marine scuticociliates, Pleuronema elegans spec. nov., P. setigerum Calkins, 1902, P. grolierei Wang et al., 2008 and Uronema orientalis spec. nov., collected from China seas, were investigated through live observation and protargol staining methods. Pleuronema elegans spec. nov. can be recognized by the combination of the following characters: size in vivo 90–115 × 45–60 µm, slender oval in outline with a distinctly pointed posterior end; about 10 prolonged caudal cilia; consistently two preoral kineties and 18 or 19 somatic kineties; membranelle 2a double-rowed with its posterior end straight; membranelle 3 three-rowed; one macronucleus; marine habitat.Uronema orientalis spec. nov. is distinguished by the following features: in vivo about 40–55 × 20–30 μm with a truncated apical plate; consistently twenty somatic kineties; membranelle 1 single-rowed and divided into two parts which comprise four and three basal bodies respectively; contractile vacuole pore positioned at the end of the second somatic kinety; marine habitat. We also provide improved diagnoses for P. grolierei Wang et al., 2008 and P. setigerum Calkins, 1902 based on current and previous reports. The small subunit rRNA gene of U. orientalis, P. elegans, P. grolierei and P. puytoraci were sequenced. Phylogenetic analyses indicate that Uronema and Pleuronema are not monophyletic.
Claudia Wylezich, Alexander Kudryavtsev, Rolf Michel, Daniele Corsaro, Julia Walochnik
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 45-51
https://doi.org/10.4467/16890027AP.15.004.2191The genus Sappinia belongs to the family Thecamoebidae within the Discosea (Amoebozoa). For long time the genus comprised only two species, S. pedata and S. diploidea, based on morphological investigations. However, recent molecular studies on gene sequences of the small subunit ribosomal RNA (SSU rRNA) gene revealed a high genetic diversity within the genus Sappinia. This indicated a larger species richness than previously assumed and the establishment of new species was predicted. Here, Sappinia platani sp. nov. (strain PL-247) is described and ultrastructurally investigated. This strain was isolated from the bark of a sycamore tree (Koblenz, Germany) like the re-described neotype of S. diploidea. The new species shows the typical characteristics of the genus such as flattened and binucleate trophozoites with a differentiation of anterior hyaloplasm and without discrete pseudopodia as well as bicellular cysts. Additionally, the new species possesses numerous endocytobionts and dictyosomes. The latter could not be found in previous EM studies of the genus Sappinia. Standing forms, a character of the species S. pedata, could be formed on older cultures of the new species but appeared extremely seldom. A loose layer of irregular, bent hair-like structures cover the plasma membrane dissimilar to the glycocalyx types as formerly detected in other Sappinia strains.
Won Je Lee
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 53-76
https://doi.org/10.4467/16890027AP.15.005.2192A total of 85 morpho-species of heterotrophic flagellates are reported from sediments at depths from 25–3000 m in the Gippsland Basin (Australia). They are drawn from the apusomonads, cercomonads, cryptomonads, euglenids, heteroloboseids, stramenopiles, thaumatomonads, and groups of uncertain taxonomic affinities (Protista incertae sedis). Three new species, Ancyromonas impluvium nov. spec.,Kurnaimonas celeris nov. spec., Sinistermonas sinistrorsus nov. spec., one combination, Psammosa unguis nov. comb., and one unidentified species are described. The biogeography of the species seen in Gippsland Basin is discussed with reference to studies in other localities. It appears that many heterotrophic flagellates are cosmopolitan.
Agata Leońska-Duniec, Bogumiła Skotarczak, Małgorzata Adamska
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 77-84
https://doi.org/10.4467/16890027AP.15.006.2193Free living amoebae (FLA) are amphizoic protozoa that are widely found in various environmental sources. They are known to cause serious human infections, including a fatal encephalitis, a blinding keratitis, and pneumonia. The main aim of the study was detection and molecular identification of Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris, Sappinia pedata, and Vermoamoeba vermiformis (formerly Hartmannella vermiformis) in artificial water bodies in North-Western Poland. We examined 86 water samples collected during 2-year period from 43 water bodies, including outdoor and indoor swimming pools, firefighting reservoirs, fountains, as well as water network. The samples were filtrated using Filta-Max® membrane filters (IDEXX Laboratories, USA) and, in order to select potentially pathogenic, thermophilic strains and to limit the number of PCR examined samples, the thermal tolerance test was carried out. Obtained filtrates were transferred to non-nutrient agar plates with E. coli. The agar plates were incubated at 37°C and then proliferated amoebae were passaged at 42°C. DNA was extracted from the thermophilic trophozoites and then polymerase chain reactions and sequence analysis were performed for molecular identification of FLA. From the 86 collected water samples 57 strains of FLA were able to proliferate at 37°C and 7 of them showed ability to proliferate at 42°C. For molecular identification ofAcanthamoeba spp. and V. vermiformis, regions of 18S rDNA were amplified. In order to detect B. mandrillaris DNA, we used mitochondrial 16S rDNA as a marker, and for detection of N. fowleri andS. pedata – ITS regions. Based on molecular analysis, isolates were classified to the genusAcanthamoeba (T4 and T11 genotypes, as well as the new genotypes detected earlier in clinical samples and named T16) and V. vermiformis species. Detected strains were highly similar or identical to pathogenic strains detected earlier in patients. Our results show a wide distribution of potential pathogenic FLA, as Acanthamoeba T4, T11, T16 genotypes, and V. vermiformis species in various artificial water bodies located in North-Western Poland and suggest a potential threat to health of humans in this part of the country.
Anatoly Bobrov, David M. Wilkinson , Yangmin QIN
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 1-8
https://doi.org/10.4467/16890027AP.15.001.2188The extent to which free-living microorganisms show cosmopolitan distributions has been a contentious aspect of microbial ecology over the last few decades. Testate amoebae are a group of free living protists that can provide important evidence for the nature of the biogeography of microorganisms because there are relatively good data on the distribution of their morpho-species (compared to many other microbial groups). Many testate amoebae appear to exhibit ubiquitous distributions, while some taxa have proven to be endemic to limited regions. The genusHoogenraadia (Gauthier-Lièvre and Thomas 1958) is of particular interest in this context as it appears to be restricted to relatively low latitudes. There are six described species of the genus: H. africana Gauthier-Lièvre and Thomas 1958, H. asiatica Wang and Min 1987, H. cryptostoma Gauthier-Lièvre and Thomas 1958, H. humicola Bonnet 1976, H. ovata Bonnet 1976, and H. sylvatica Vucetich 1974. However, information on these taxa is scattered through a number of different papers – here we provide a summary of what is known about the taxonomy and ecology of this genus. We also reinterpret recent new records of putative H. africana from China (suggesting this identification is not reliable). As an example of a protist taxon largely restricted to the tropics this genus is of particular interest in microbial biogeography and this paper discusses its morphology, ecology and distribution in this context.
Peter Vďačný, Mann Kyoon Shin, Ji Hye Kim, Seok Won Jang, Shahed Uddin Ahmed Shazib, Ľubomír Rajter
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 9-29
https://doi.org/10.4467/16890027AP.15.002.2189Pleurostomatids are raptorial ciliates that form a very distinct group within the Haptoria. Traditionally, the order Pleurostomatida was divided into two families: the Amphileptidae with two perioral kineties and a suture formed by the right side ciliary rows, and the Litonotidae with three perioral kineties and without suture. However, molecular phylogenies depicted the “traditional” Amphileptidae as a paraphyletic assemblage nesting also the Litonotidae. To overcome this problem we have analyzed genealogy of pleurostomatids using morphological data and 18S rRNA gene sequences, including newly sequenced genera Acineria and Kentrophyllum. Specifically, we have combined a morphological and molecular approach and have used also some other phylogenetic tools such as phylogenetic networks, split spectrum analysis, quartet mapping as well as the likelihood method of tracing history of morphological characters. These analyses show that: (1) there are not two but three distinct pleurostomatid lineages – Epiphyllidae fam. nov., Amphileptidae and Litonotidae; (2) epiphyllids (Epiphyllum + Kentrophyllum) represent a basal pleurostomatid group which is defined by two perioral kineties, by the presence of a suture on both the right and the left side of the body, by the loss of the oral bulge extrusomes, and by the extrusome fringe extending all around the body except for the oral region; (3) the families Amphileptidae and Litonotidae are monophyletic each, and represent sister groups; (4) Acineria belongs to the Litonotidae, as already indicated by morphological data; (5) Loxophyllum is a monophyletic and crown genus of the Litonotidae; and (6) Litonotus is paraphyletic, which could be very likely caused by a rapid radiation event that did not allow primary nucleotide homologies to be fixed.
Xuming Pan, Feng Gao, Miao Miao, Khaled A. S. Al-Rasheid, Honggang Ma, Xinpeng Fan, Jie Huang
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 31-43
https://doi.org/10.4467/16890027AP.15.003.2190The morphology and infraciliature of four marine scuticociliates, Pleuronema elegans spec. nov., P. setigerum Calkins, 1902, P. grolierei Wang et al., 2008 and Uronema orientalis spec. nov., collected from China seas, were investigated through live observation and protargol staining methods. Pleuronema elegans spec. nov. can be recognized by the combination of the following characters: size in vivo 90–115 × 45–60 µm, slender oval in outline with a distinctly pointed posterior end; about 10 prolonged caudal cilia; consistently two preoral kineties and 18 or 19 somatic kineties; membranelle 2a double-rowed with its posterior end straight; membranelle 3 three-rowed; one macronucleus; marine habitat.Uronema orientalis spec. nov. is distinguished by the following features: in vivo about 40–55 × 20–30 μm with a truncated apical plate; consistently twenty somatic kineties; membranelle 1 single-rowed and divided into two parts which comprise four and three basal bodies respectively; contractile vacuole pore positioned at the end of the second somatic kinety; marine habitat. We also provide improved diagnoses for P. grolierei Wang et al., 2008 and P. setigerum Calkins, 1902 based on current and previous reports. The small subunit rRNA gene of U. orientalis, P. elegans, P. grolierei and P. puytoraci were sequenced. Phylogenetic analyses indicate that Uronema and Pleuronema are not monophyletic.
Claudia Wylezich, Alexander Kudryavtsev, Rolf Michel, Daniele Corsaro, Julia Walochnik
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 45-51
https://doi.org/10.4467/16890027AP.15.004.2191The genus Sappinia belongs to the family Thecamoebidae within the Discosea (Amoebozoa). For long time the genus comprised only two species, S. pedata and S. diploidea, based on morphological investigations. However, recent molecular studies on gene sequences of the small subunit ribosomal RNA (SSU rRNA) gene revealed a high genetic diversity within the genus Sappinia. This indicated a larger species richness than previously assumed and the establishment of new species was predicted. Here, Sappinia platani sp. nov. (strain PL-247) is described and ultrastructurally investigated. This strain was isolated from the bark of a sycamore tree (Koblenz, Germany) like the re-described neotype of S. diploidea. The new species shows the typical characteristics of the genus such as flattened and binucleate trophozoites with a differentiation of anterior hyaloplasm and without discrete pseudopodia as well as bicellular cysts. Additionally, the new species possesses numerous endocytobionts and dictyosomes. The latter could not be found in previous EM studies of the genus Sappinia. Standing forms, a character of the species S. pedata, could be formed on older cultures of the new species but appeared extremely seldom. A loose layer of irregular, bent hair-like structures cover the plasma membrane dissimilar to the glycocalyx types as formerly detected in other Sappinia strains.
Won Je Lee
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 53-76
https://doi.org/10.4467/16890027AP.15.005.2192A total of 85 morpho-species of heterotrophic flagellates are reported from sediments at depths from 25–3000 m in the Gippsland Basin (Australia). They are drawn from the apusomonads, cercomonads, cryptomonads, euglenids, heteroloboseids, stramenopiles, thaumatomonads, and groups of uncertain taxonomic affinities (Protista incertae sedis). Three new species, Ancyromonas impluvium nov. spec.,Kurnaimonas celeris nov. spec., Sinistermonas sinistrorsus nov. spec., one combination, Psammosa unguis nov. comb., and one unidentified species are described. The biogeography of the species seen in Gippsland Basin is discussed with reference to studies in other localities. It appears that many heterotrophic flagellates are cosmopolitan.
Agata Leońska-Duniec, Bogumiła Skotarczak, Małgorzata Adamska
Acta Protozoologica, Volume 54, Issue 1, 2015, pp. 77-84
https://doi.org/10.4467/16890027AP.15.006.2193Free living amoebae (FLA) are amphizoic protozoa that are widely found in various environmental sources. They are known to cause serious human infections, including a fatal encephalitis, a blinding keratitis, and pneumonia. The main aim of the study was detection and molecular identification of Acanthamoeba spp., Naegleria fowleri, Balamuthia mandrillaris, Sappinia pedata, and Vermoamoeba vermiformis (formerly Hartmannella vermiformis) in artificial water bodies in North-Western Poland. We examined 86 water samples collected during 2-year period from 43 water bodies, including outdoor and indoor swimming pools, firefighting reservoirs, fountains, as well as water network. The samples were filtrated using Filta-Max® membrane filters (IDEXX Laboratories, USA) and, in order to select potentially pathogenic, thermophilic strains and to limit the number of PCR examined samples, the thermal tolerance test was carried out. Obtained filtrates were transferred to non-nutrient agar plates with E. coli. The agar plates were incubated at 37°C and then proliferated amoebae were passaged at 42°C. DNA was extracted from the thermophilic trophozoites and then polymerase chain reactions and sequence analysis were performed for molecular identification of FLA. From the 86 collected water samples 57 strains of FLA were able to proliferate at 37°C and 7 of them showed ability to proliferate at 42°C. For molecular identification ofAcanthamoeba spp. and V. vermiformis, regions of 18S rDNA were amplified. In order to detect B. mandrillaris DNA, we used mitochondrial 16S rDNA as a marker, and for detection of N. fowleri andS. pedata – ITS regions. Based on molecular analysis, isolates were classified to the genusAcanthamoeba (T4 and T11 genotypes, as well as the new genotypes detected earlier in clinical samples and named T16) and V. vermiformis species. Detected strains were highly similar or identical to pathogenic strains detected earlier in patients. Our results show a wide distribution of potential pathogenic FLA, as Acanthamoeba T4, T11, T16 genotypes, and V. vermiformis species in various artificial water bodies located in North-Western Poland and suggest a potential threat to health of humans in this part of the country.
Publication date: 18.09.2014
Editor-in-Chief: Krzysztof Wiąckowski
Sabine Agatha
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 287-294
https://doi.org/10.4467/16890027AP.14.026.2021The oligotrichid ciliate Strombidium coronatum (Leegaard, 1915) Kahl, 1932 is redescribed from plankton samples taken in the Irish Sea, using live observation, protargol impregnation, and scanning electron microscopy. The species is characterized by a conspicuous, uniquelly shaped peristome, which is flat and roughly triangular and extends in the sagittal plane. The Irish Sea specimens measure ~ 45 × 25 µm in vivo and ~ 40 × 24 µm after protargol impregnation. The girdle kinety is equatorial, ostensibly continuous, and composed of ~ 100 dikinetids. The ventral kinety extends longitudinally on the posterior fifth of the cell and is composed of about five dikinetids. The adoral zone of membranelles is widely open and composed of ~ 18 collar and ~ 12 buccal membranelles; the collar portion is disconnected from the buccal portion. The shape and orientation of the opisthe’s adoral zone of membranelles are apparently extraordinary, i.e., the membranelles form an inverted L-shaped stripe extending longitudinally in the elongated posterior cell portion of dividers.
Atef Omar, Wilhelm Foissner
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 295-311
https://doi.org/10.4467/16890027AP.14.027.2022Vasily V. Zlatogursky
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 313-324
https://doi.org/10.4467/16890027AP.14.021.1776Two new species of centrohelid heliozoans Acanthocystis costata and Choanocystis symna from a freshwater lake on Valamo Island and a freshwater pool in St. Petersburg (North-Western Russia) were studied with light and electron microscopy. Sequences of 18S rDNA were obtained for both species.Choanocystis symna has dumbbell-shaped plate scales (4.4–5.0 × 1.62–1.90 µm) and spine scales (3.9–6.7 µm) bearing from 3 to 5 (usually four) short teeth on the distal end. Acanthocystis costata has oval plate scales (1.3–3.7 × 0.9–1.9 µm), bearing numerous granules as well as radial slits and spine scales (2.1–9.5 µm) with 4–6 teeth on the distal end. Acanthocystis costata and Acanthocystis nichollsi are similar in having slit-bearing plate scales and group together on the 18S rDNA tree. The presence of large particles of unknown nature was observed in food vacuoles of Acanthocystis costata.
Alexander Kudryavtsev
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 325-333
https://doi.org/10.4467/16890027AP.14.020.1776Adalgisa Fernanda Cabral, Bárbara Dunck, Fernando Miranda Lansac-Toha, Liliana Rodrigues, Laura Roberta Pinto Utz, Luiz Felipe Machadovelho
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 335-340
https://doi.org/10.4467/16890027AP.14.028.2023Epibiosis is a facultative association between two organisms: the epibiont, which colonizes the surface of living substrates, and the basibiont, which hosts the epibionts. Among protists, while numerous accounts exist for ciliates as epibionts of zooplankton, little information is available about the occurrence of this relationship between flagellates and microcrustaceans in the neotropics. During a survey on the epibiotic relationship between ciliated protists and planktonic copepods in a tropical floodplain, we reported for the first time the occurrence of Colacium vesiculosum as an epibiont onThermocyclops minutus and Notodiaptomus amazonicus from southern Brazil. The mean infestation prevalence was significantly higher on adults 30.53% (± 2.85) in comparison with copepodites 0.87% (± 0.55). When hosts were separated by order (Calanoida and Cyclopoida) copepodites presented a mean infestation prevalence of 0.92% (± 0.85) and 0.83% (± 0.60) respectively, while adults had a mean prevalence of 29.55% (± 6.8) and 30.13% (± 5.83), which could be explained by the fact that adult copepods provide a more stable substrate for epibionts.
Sabine Agatha
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 287-294
https://doi.org/10.4467/16890027AP.14.026.2021The oligotrichid ciliate Strombidium coronatum (Leegaard, 1915) Kahl, 1932 is redescribed from plankton samples taken in the Irish Sea, using live observation, protargol impregnation, and scanning electron microscopy. The species is characterized by a conspicuous, uniquelly shaped peristome, which is flat and roughly triangular and extends in the sagittal plane. The Irish Sea specimens measure ~ 45 × 25 µm in vivo and ~ 40 × 24 µm after protargol impregnation. The girdle kinety is equatorial, ostensibly continuous, and composed of ~ 100 dikinetids. The ventral kinety extends longitudinally on the posterior fifth of the cell and is composed of about five dikinetids. The adoral zone of membranelles is widely open and composed of ~ 18 collar and ~ 12 buccal membranelles; the collar portion is disconnected from the buccal portion. The shape and orientation of the opisthe’s adoral zone of membranelles are apparently extraordinary, i.e., the membranelles form an inverted L-shaped stripe extending longitudinally in the elongated posterior cell portion of dividers.
Atef Omar, Wilhelm Foissner
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 295-311
https://doi.org/10.4467/16890027AP.14.027.2022Vasily V. Zlatogursky
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 313-324
https://doi.org/10.4467/16890027AP.14.021.1776Two new species of centrohelid heliozoans Acanthocystis costata and Choanocystis symna from a freshwater lake on Valamo Island and a freshwater pool in St. Petersburg (North-Western Russia) were studied with light and electron microscopy. Sequences of 18S rDNA were obtained for both species.Choanocystis symna has dumbbell-shaped plate scales (4.4–5.0 × 1.62–1.90 µm) and spine scales (3.9–6.7 µm) bearing from 3 to 5 (usually four) short teeth on the distal end. Acanthocystis costata has oval plate scales (1.3–3.7 × 0.9–1.9 µm), bearing numerous granules as well as radial slits and spine scales (2.1–9.5 µm) with 4–6 teeth on the distal end. Acanthocystis costata and Acanthocystis nichollsi are similar in having slit-bearing plate scales and group together on the 18S rDNA tree. The presence of large particles of unknown nature was observed in food vacuoles of Acanthocystis costata.
Alexander Kudryavtsev
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 325-333
https://doi.org/10.4467/16890027AP.14.020.1776Adalgisa Fernanda Cabral, Bárbara Dunck, Fernando Miranda Lansac-Toha, Liliana Rodrigues, Laura Roberta Pinto Utz, Luiz Felipe Machadovelho
Acta Protozoologica, Volume 53, Issue 4, 2014, pp. 335-340
https://doi.org/10.4467/16890027AP.14.028.2023Epibiosis is a facultative association between two organisms: the epibiont, which colonizes the surface of living substrates, and the basibiont, which hosts the epibionts. Among protists, while numerous accounts exist for ciliates as epibionts of zooplankton, little information is available about the occurrence of this relationship between flagellates and microcrustaceans in the neotropics. During a survey on the epibiotic relationship between ciliated protists and planktonic copepods in a tropical floodplain, we reported for the first time the occurrence of Colacium vesiculosum as an epibiont onThermocyclops minutus and Notodiaptomus amazonicus from southern Brazil. The mean infestation prevalence was significantly higher on adults 30.53% (± 2.85) in comparison with copepodites 0.87% (± 0.55). When hosts were separated by order (Calanoida and Cyclopoida) copepodites presented a mean infestation prevalence of 0.92% (± 0.85) and 0.83% (± 0.60) respectively, while adults had a mean prevalence of 29.55% (± 6.8) and 30.13% (± 5.83), which could be explained by the fact that adult copepods provide a more stable substrate for epibionts.
Publication date: 27.08.2014
Editor-in-Chief: Krzysztof Wiąckowski
Helge Abildhauge Thomsen, Jette Buch Østergaard
Acta Protozoologica, Volume 53, Issue 3, 2014, pp. 235-256
https://doi.org/10.4467/16890027AP.14.022.1997Mi-Hyun Park, Gi-Sik Min
Acta Protozoologica, Volume 53, Issue 3, 2014, pp. 257-268
https://doi.org/10.4467/16890027AP.14.023.1998Gilberto Flausino, Carlos W. G. Lopes, Walter L. Teixeira-Fillho, Tassia T. Furtado, Douglas Mcintosh, Bruno P. Berto
Acta Protozoologica, Volume 53, Issue 3, 2014, pp. 269-276
https://doi.org/10.4467/16890027AP.14.024.1999Coccidiosis in Guinea pigs (Cavia porcellus) has been frequently associated with the presence ofEimeria caviae; however, this coccidium has never been characterized in detail. This study aimed to present the phenotypic and genotypic characterization of E. caviae from guinea pigs reared under rustic breeding conditions in Brazil. Eimeria caviae oocysts are polymorphic, being sub-spherical, ovoidal or ellipsoidal, 20.9 × 17.7 µm, with a smooth or slightly rough and bi-layered wall, ~ 1.0 µm. Micropyle and oocyst residuum are absent, but one polar granule is present. Sporocysts are ellipsoidal, 10.8 × 6.4 µm. Stieda and parastieda bodies are present, sporocyst residuum is present and sporozoites posses a refractile body and a nucleus. Linear regressions and histograms were performed and confirmed the polymorphism of the oocysts. The internal transcribed spacer 1 of the ribosomal RNA gene (ITS-1 rRNA) of the isolates was sequenced and showed no significant similarity to the orthologous region of other Eimeria species.
Kálmán Molnár, Edit Eszterbauer, Csaba F. Guti, Csaba Székely
Acta Protozoologica, Volume 53, Issue 3, 2014, pp. 277-285
https://doi.org/10.4467/16890027AP.14.025.2000Two new Myxobolus species, M. bjoerknae sp. n. and M. lamellobasis sp. n. have been described from the gills of white bream, Blicca bjoerkna. Plasmodia of M. bjoerknae sp. n. developed in the connective tissue inside the cartilaginous gill arch, while plasmodia of M. lamellobasis sp. n. seem to start their development in the multilayered epithelium between two lamellae close to the base of gill filaments. Then they may bulge out of the interlamellar space fused to a large bulk locating at the base of filaments. The large, ellipsoidal spores of M. bjoerknae sp. n. 17.4 × 13.1 µm in size, resembled the spores of other species developing in the gill arch (e.g. M. fundamentalis, M. gayerae, and M. pfeifferi), but differed from them in its 18S rDNA sequence. Roundish spores of M. lamellobasis sp. n. with a size of 11.1 × 8.6 µm resembled the spores of M. impressus developing interlamellarly and the spores of M. rotundus, M. parviformis, and M. muellericus having intralamellar localization. However, the detected genetic difference clearly distinguished it from the other species developing in similar tissue location. The phylogenetic location of the two newly described species seems to correlate both with spore shape and fish host species.
Helge Abildhauge Thomsen, Jette Buch Østergaard
Acta Protozoologica, Volume 53, Issue 3, 2014, pp. 235-256
https://doi.org/10.4467/16890027AP.14.022.1997Mi-Hyun Park, Gi-Sik Min
Acta Protozoologica, Volume 53, Issue 3, 2014, pp. 257-268
https://doi.org/10.4467/16890027AP.14.023.1998Gilberto Flausino, Carlos W. G. Lopes, Walter L. Teixeira-Fillho, Tassia T. Furtado, Douglas Mcintosh, Bruno P. Berto
Acta Protozoologica, Volume 53, Issue 3, 2014, pp. 269-276
https://doi.org/10.4467/16890027AP.14.024.1999Coccidiosis in Guinea pigs (Cavia porcellus) has been frequently associated with the presence ofEimeria caviae; however, this coccidium has never been characterized in detail. This study aimed to present the phenotypic and genotypic characterization of E. caviae from guinea pigs reared under rustic breeding conditions in Brazil. Eimeria caviae oocysts are polymorphic, being sub-spherical, ovoidal or ellipsoidal, 20.9 × 17.7 µm, with a smooth or slightly rough and bi-layered wall, ~ 1.0 µm. Micropyle and oocyst residuum are absent, but one polar granule is present. Sporocysts are ellipsoidal, 10.8 × 6.4 µm. Stieda and parastieda bodies are present, sporocyst residuum is present and sporozoites posses a refractile body and a nucleus. Linear regressions and histograms were performed and confirmed the polymorphism of the oocysts. The internal transcribed spacer 1 of the ribosomal RNA gene (ITS-1 rRNA) of the isolates was sequenced and showed no significant similarity to the orthologous region of other Eimeria species.
Kálmán Molnár, Edit Eszterbauer, Csaba F. Guti, Csaba Székely
Acta Protozoologica, Volume 53, Issue 3, 2014, pp. 277-285
https://doi.org/10.4467/16890027AP.14.025.2000Two new Myxobolus species, M. bjoerknae sp. n. and M. lamellobasis sp. n. have been described from the gills of white bream, Blicca bjoerkna. Plasmodia of M. bjoerknae sp. n. developed in the connective tissue inside the cartilaginous gill arch, while plasmodia of M. lamellobasis sp. n. seem to start their development in the multilayered epithelium between two lamellae close to the base of gill filaments. Then they may bulge out of the interlamellar space fused to a large bulk locating at the base of filaments. The large, ellipsoidal spores of M. bjoerknae sp. n. 17.4 × 13.1 µm in size, resembled the spores of other species developing in the gill arch (e.g. M. fundamentalis, M. gayerae, and M. pfeifferi), but differed from them in its 18S rDNA sequence. Roundish spores of M. lamellobasis sp. n. with a size of 11.1 × 8.6 µm resembled the spores of M. impressus developing interlamellarly and the spores of M. rotundus, M. parviformis, and M. muellericus having intralamellar localization. However, the detected genetic difference clearly distinguished it from the other species developing in similar tissue location. The phylogenetic location of the two newly described species seems to correlate both with spore shape and fish host species.
Publication date: 26.05.2014
Editor-in-Chief: Krzysztof Wiąckowski
Naveed Ahmed Khan, Junaid Iqbal, Ruqaiyyah Siddiqui
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 139-144
https://doi.org/10.4467/16890027AP.14.013.1594The ability to detect food in the environment is an essential function among all living organisms and must have arisen at the beginning of life. The anatomical, morphological and molecular features involved in taste and smell may differ among disparate groups, but the principle of chemoreception is conserved. Here we debate the sense of taste and smell in the feeding behaviour of the unicellular protist, Acanthamoeba.
Helge Abildhauge Thomsen, Jette Buch Østergaard
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 145-157
https://doi.org/10.4467/16890027AP.14.014.1595The genus Calciarcus is revisited here with the purpose of providing, based on additional sampling from both polar regions, an update on species diversity and morphology that can serve as a reference for future work. The geographic realm of the genus is significantly widened and a case is built based on consistency in appearance in favour of adding Calciarcus spp. to the well-defined community of bipolar weakly calcified coccolithophorid genera. Despite the multitude of specimens available for analysis and the fact that the specimens examined distribute themselves within three clusters based on morphological features of coccolith superstructures, it has not been possible at this stage to define a robust framework for differentiation among species of Calciarcus. Circumstantial evidence exist linking species of Wigwamma with species of Calciarcus in haploid-diploid life cycles.
Wilhelm Foissner, Klaus W. Wolf, Santosh Kumar, Pablo Quintela-Alonso
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 159-194
https://doi.org/10.4467/16890027AP.14.015.1596There is a widespread belief that spathidiids have few morphological features. In contrast, we show a rich morphological diversity in five new species discovered in tank bromeliads from the Caribbean, using live observation; protargol impregnation; morphometry; scanning electron microscopy; and resting cyst morphology, demonstrating lepidosomes (organic scales) for the first time in spathidiid haptoria. Arcuospathidium bromelicola nov. spec. is very similar to the previously described A. muscorum but its resting cyst has conspicuous, pillar-shaped lepidosomes on the surface. Protospathidium lepidosomatum nov. spec. is very similar to the previously described P. muscicola but has outstanding, nipple-shaped (vs. conical) lepidosomes on the cyst surface. Spathidium bromeliophilum nov. spec., whose ontogenesis is highly similar to that of S. turgitorum, differs from similar species by the body length:width ratio, the number of ciliary rows, the shape of the oral bulge, and details of the ciliary pattern. Spathidium bromelicola nov. spec. is similar to S. muscicola (extrusomes bluntly fusiform and 4 µm long vs. rod-shaped and > 15 µm long) and S. stammeri (resting cyst wall smooth vs. spinous). Spathidium wolfi nov. spec. has an anterior and a posterior contractile vacuole. It differs from the supposed nearest relative, S. faurefremieti, by body size (on average 135 × 25 µm vs. 240 × 17 µm), the shape of the macronucleus (moniliform vs. a long, tortuous strand), and the total number of dorsal brush bristles (on average 47 vs. 72). The bent oral bulge of Arcuospathidium bromelicola and Spathidium bromeliophilum as well as the occurrence of lepidosomes on the cyst surface of Arcuospathidium bromelicola and Protospathidium lepidosomatum are discussed.
Jae-Ho Jung, Kyung-Min Park, Gi-Sik Min
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 195-206
https://doi.org/10.4467/16890027AP.14.016.1597A new soil ciliate, Pseudouroleptus jejuensis, was discovered from Jeju Island, South Korea and described based on live observation, protargol impregnation, and SSU rRNA gene sequence analyses. Pseudouroleptus jejuensis differs from other congeneric species mainly by number of dorsal kineties (5 vs. 4). Based on our observation of late dividers, we confirm that the dorsal kinety anlage 3 forms 3 kineties (i.e., dorsal kineties 3–5), and the dorsal kinety anlagen 1–3 form 3–5/1–2/0 caudal cirri, respectively. Our gene trees support the assignment of this new species in Pseudouroleptus to full supporting values.
Micah Dunthorn, Meaghan Hall, Wilhelm Foissner, Thorsten Stoeck, Laura A. Katz
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 207-213
https://doi.org/10.4467/16890027AP.14.017.1598Mitochondrial SSU-rDNA has been used recently to infer phylogenetic relationships among a few ciliates. Here, this locus is compared with nuclear SSU-rDNA for uncovering the deepest nodes in the ciliate tree of life using broad taxon sampling. Nuclear and mitochondrial SSU-rDNA reveal the same relationships for nodes well-supported in previously-published nuclear SSU-rDNA studies, although support for many nodes in the mitochondrial SSU-rDNA tree are low. Mitochondrial SSU-rDNA infers a monophyletic Colpodea with high node support only from Bayesian inference, and in the concatenated tree (nuclear plus mitochondrial SSU-rDNA) monophyly of the Colpodea is supported with moderate to high node support from maximum likelihood and Bayesian inference. In the monophyletic Phyllopharyngea, the Suctoria is inferred to be sister to the Cyrtophora in the mitochondrial, nuclear, and concatenated SSU-rDNA trees with moderate to high node support from maximum likelihood and Bayesian inference. Together these data point to the power of adding mitochondrial SSU-rDNA as a standard locus for ciliate molecular phylogenetic inferences.
Abdel-Azeem S. Abdel-Baki, Saleh Al-Quraishy, Mohamed A. Dkhil, Elsa Oliveira, Graça Casal, Carlos Azevedo
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 215-221
https://doi.org/10.4467/16890027AP.14.018.1599Genus Perkinsus Levine, 1978 (Alveolata, Perkinsidae) an intracellular pathogenic parasite is described from the mantle and gill filaments of a commercially important clam, Meretrix meretrix, collected from the Arabian Gulf, Saudi Arabia. This genus contains currently seven named species: P. marinus, P. olseni (P. atlanticus), P. chesapeaki (P. andrewsi), P. mediterraneus, P. honshuensis, P. beihaiensis and P. qugwadi. Meanwhile, some unnamed Perkinsus sp. have been described in wide variety of mollusc species. Ultrastructural features of Perkinsus sp. trophozites and the host reaction are described. The different developmental stages of trophozoites appeared as single or grouped cells surrounded by amorphous material that constituted cysts or nodules randomly distributed throughout the connective tissue of the mantle. The early trophozoites were generally spherical to ellipsoidal with a circular nucleus containing a prominent central nucleolus. The cytoplasm had several small vacuoles which coalesce to form a great vacuole in the later trophozoites and the nucleus becomes eccentric. Some lomosomes were observed between the wall and the plasmalemma of trophozoites. A large number of degraded and pyknotic cell and several cellular structure with lysed aspects were encountered in the surrounding area near the cysts. Ultrastructural data showed that the lysed granular cells and the coalescence of the granules result in the cyst that encapsulates various trophozoites. In the current study, we describe for the first time the presence of Perkinsus sp. as well as the host reaction in clams from the Saudi Arabian coasts.
Mustafa Yaman, Çağrı Bekircan, Renate Radek, Andreas Linde
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 223-232
https://doi.org/10.4467/16890027AP.14.019.1600John R. Dolan
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 233-234
Cilia and Flagella – Ciliates and Flagellates: Ultrastructure and cell biology, function and systematics, symbiosis and biodiversity edited by Klaus Hausmann and Renate Radek. Stuttgart: Schweizerbart Science Publishers. 2014. 299 pp. Hardback ISBN 978-3-510-65287-7. € 39.80
Naveed Ahmed Khan, Junaid Iqbal, Ruqaiyyah Siddiqui
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 139-144
https://doi.org/10.4467/16890027AP.14.013.1594The ability to detect food in the environment is an essential function among all living organisms and must have arisen at the beginning of life. The anatomical, morphological and molecular features involved in taste and smell may differ among disparate groups, but the principle of chemoreception is conserved. Here we debate the sense of taste and smell in the feeding behaviour of the unicellular protist, Acanthamoeba.
Helge Abildhauge Thomsen, Jette Buch Østergaard
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 145-157
https://doi.org/10.4467/16890027AP.14.014.1595The genus Calciarcus is revisited here with the purpose of providing, based on additional sampling from both polar regions, an update on species diversity and morphology that can serve as a reference for future work. The geographic realm of the genus is significantly widened and a case is built based on consistency in appearance in favour of adding Calciarcus spp. to the well-defined community of bipolar weakly calcified coccolithophorid genera. Despite the multitude of specimens available for analysis and the fact that the specimens examined distribute themselves within three clusters based on morphological features of coccolith superstructures, it has not been possible at this stage to define a robust framework for differentiation among species of Calciarcus. Circumstantial evidence exist linking species of Wigwamma with species of Calciarcus in haploid-diploid life cycles.
Wilhelm Foissner, Klaus W. Wolf, Santosh Kumar, Pablo Quintela-Alonso
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 159-194
https://doi.org/10.4467/16890027AP.14.015.1596There is a widespread belief that spathidiids have few morphological features. In contrast, we show a rich morphological diversity in five new species discovered in tank bromeliads from the Caribbean, using live observation; protargol impregnation; morphometry; scanning electron microscopy; and resting cyst morphology, demonstrating lepidosomes (organic scales) for the first time in spathidiid haptoria. Arcuospathidium bromelicola nov. spec. is very similar to the previously described A. muscorum but its resting cyst has conspicuous, pillar-shaped lepidosomes on the surface. Protospathidium lepidosomatum nov. spec. is very similar to the previously described P. muscicola but has outstanding, nipple-shaped (vs. conical) lepidosomes on the cyst surface. Spathidium bromeliophilum nov. spec., whose ontogenesis is highly similar to that of S. turgitorum, differs from similar species by the body length:width ratio, the number of ciliary rows, the shape of the oral bulge, and details of the ciliary pattern. Spathidium bromelicola nov. spec. is similar to S. muscicola (extrusomes bluntly fusiform and 4 µm long vs. rod-shaped and > 15 µm long) and S. stammeri (resting cyst wall smooth vs. spinous). Spathidium wolfi nov. spec. has an anterior and a posterior contractile vacuole. It differs from the supposed nearest relative, S. faurefremieti, by body size (on average 135 × 25 µm vs. 240 × 17 µm), the shape of the macronucleus (moniliform vs. a long, tortuous strand), and the total number of dorsal brush bristles (on average 47 vs. 72). The bent oral bulge of Arcuospathidium bromelicola and Spathidium bromeliophilum as well as the occurrence of lepidosomes on the cyst surface of Arcuospathidium bromelicola and Protospathidium lepidosomatum are discussed.
Jae-Ho Jung, Kyung-Min Park, Gi-Sik Min
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 195-206
https://doi.org/10.4467/16890027AP.14.016.1597A new soil ciliate, Pseudouroleptus jejuensis, was discovered from Jeju Island, South Korea and described based on live observation, protargol impregnation, and SSU rRNA gene sequence analyses. Pseudouroleptus jejuensis differs from other congeneric species mainly by number of dorsal kineties (5 vs. 4). Based on our observation of late dividers, we confirm that the dorsal kinety anlage 3 forms 3 kineties (i.e., dorsal kineties 3–5), and the dorsal kinety anlagen 1–3 form 3–5/1–2/0 caudal cirri, respectively. Our gene trees support the assignment of this new species in Pseudouroleptus to full supporting values.
Micah Dunthorn, Meaghan Hall, Wilhelm Foissner, Thorsten Stoeck, Laura A. Katz
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 207-213
https://doi.org/10.4467/16890027AP.14.017.1598Mitochondrial SSU-rDNA has been used recently to infer phylogenetic relationships among a few ciliates. Here, this locus is compared with nuclear SSU-rDNA for uncovering the deepest nodes in the ciliate tree of life using broad taxon sampling. Nuclear and mitochondrial SSU-rDNA reveal the same relationships for nodes well-supported in previously-published nuclear SSU-rDNA studies, although support for many nodes in the mitochondrial SSU-rDNA tree are low. Mitochondrial SSU-rDNA infers a monophyletic Colpodea with high node support only from Bayesian inference, and in the concatenated tree (nuclear plus mitochondrial SSU-rDNA) monophyly of the Colpodea is supported with moderate to high node support from maximum likelihood and Bayesian inference. In the monophyletic Phyllopharyngea, the Suctoria is inferred to be sister to the Cyrtophora in the mitochondrial, nuclear, and concatenated SSU-rDNA trees with moderate to high node support from maximum likelihood and Bayesian inference. Together these data point to the power of adding mitochondrial SSU-rDNA as a standard locus for ciliate molecular phylogenetic inferences.
Abdel-Azeem S. Abdel-Baki, Saleh Al-Quraishy, Mohamed A. Dkhil, Elsa Oliveira, Graça Casal, Carlos Azevedo
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 215-221
https://doi.org/10.4467/16890027AP.14.018.1599Genus Perkinsus Levine, 1978 (Alveolata, Perkinsidae) an intracellular pathogenic parasite is described from the mantle and gill filaments of a commercially important clam, Meretrix meretrix, collected from the Arabian Gulf, Saudi Arabia. This genus contains currently seven named species: P. marinus, P. olseni (P. atlanticus), P. chesapeaki (P. andrewsi), P. mediterraneus, P. honshuensis, P. beihaiensis and P. qugwadi. Meanwhile, some unnamed Perkinsus sp. have been described in wide variety of mollusc species. Ultrastructural features of Perkinsus sp. trophozites and the host reaction are described. The different developmental stages of trophozoites appeared as single or grouped cells surrounded by amorphous material that constituted cysts or nodules randomly distributed throughout the connective tissue of the mantle. The early trophozoites were generally spherical to ellipsoidal with a circular nucleus containing a prominent central nucleolus. The cytoplasm had several small vacuoles which coalesce to form a great vacuole in the later trophozoites and the nucleus becomes eccentric. Some lomosomes were observed between the wall and the plasmalemma of trophozoites. A large number of degraded and pyknotic cell and several cellular structure with lysed aspects were encountered in the surrounding area near the cysts. Ultrastructural data showed that the lysed granular cells and the coalescence of the granules result in the cyst that encapsulates various trophozoites. In the current study, we describe for the first time the presence of Perkinsus sp. as well as the host reaction in clams from the Saudi Arabian coasts.
Mustafa Yaman, Çağrı Bekircan, Renate Radek, Andreas Linde
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 223-232
https://doi.org/10.4467/16890027AP.14.019.1600John R. Dolan
Acta Protozoologica, Volume 53, Issue 2, 2014, pp. 233-234
Cilia and Flagella – Ciliates and Flagellates: Ultrastructure and cell biology, function and systematics, symbiosis and biodiversity edited by Klaus Hausmann and Renate Radek. Stuttgart: Schweizerbart Science Publishers. 2014. 299 pp. Hardback ISBN 978-3-510-65287-7. € 39.80
Publication date: 2014
Editor-in-Chief: Krzysztof Wiąckowski
Guest editors: John R. Dolan and David J. S. Montagnes:
David J. S. Montagnes, John R. Dolan
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 1-2
https://doi.org/10.4467/16890027AP.14.001.1438The Chukchi Sea was sampled in August of 2011, a year of near-normal sea ice among recent years, and again in August 2012, a year of all time record low sea ice. We exploited this sampling to test the hypothesis that different sea ice conditions are associated with differences in abundances or species composition of microzooplankton through an examination of tintinnids and radiolarians. From 18 stations in 2011, and 19 stations in 2012, organisms were enumerated in plankton net tow material, and chlorophyll determinations made (total and ≤ 20 µm) from discrete depth samples. We found that the low sea ice conditions of 2012 were associated with higher chlorophyll concentrations (both total and the ≤ 20 µm size fraction), compared to 2011. However, tintinnid ciliates and radiolarians were much lower in concentration, by about an order of magnitude, compared to 2011. In both years the radiolarian assemblage was dominated by Amphiselma setosa. The species composition of the tintinnid ciliates was similar in the two years, but there were distinct differences in the relative abundances of certain species. The 2012, low sea ice assemblage, was dominated by small forms in contrast to 2011, when large species were the most abundant. We present these findings in detail and discuss possible explanations for the apparent differences in the microzooplankton communities associated with distinct sea ice conditions in the Chukchi Sea
Tom Fenchel
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 3-12
https://doi.org/10.4467/16890027AP.13.019.1117Aerobic protozoa can maintain fully aerobic metabolic rates even at very low O2-tensions; this is related to their small sizes. Many – or perhaps all – protozoa show particular preferences for a given range of O2-tensions. The reasons for this and the role for their distribution in nature are discussed and examples of protozoan biota in O2-gradients in aquatic systems are presented. Facultative anaerobes capable of both aerobic and anaerobic growth are probably common within several protozoan taxa. It is concluded that further progress in this area is contingent on physiological studies of phenotypes.
Celia Bulit
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 13-27
https://doi.org/10.4467/16890027AP.14.003.1440Analysing the spatio-temporal distribution of protistan microplankton has faced both conceptual and technical difficulties. However, recognition of a need to study planktonic patchiness, application of a major geology-based methodology (geostatistics) to ecology, and advances in computational technologies have widened the interest in this topic and made it more assessable. This review provides methodological and conceptual guidance on the application of geostatistics to microplankton analysis, using ciliates as example model organisms. Applying geostatistical analysis (and complementary methodologies) to the distribution of ciliate and phytoplankton reveals that attributes of their populations and assemblages (e.g. abundance, biomass, production, diversity) are patchily distributed at multiple spatial-scales in different aquatic environments, and these change over time. Data examined from several environments and scales exhibit distinct patterns of patches regarding their shape, density, and structure; these data can then be used to suggest a behavioural niche-separation of ciliates and the influence of patchiness on the rate processes of food webs. Throughout the review, basic guidance is provided for interpreting where, when, and why planktonic ciliate are so distributed, and directions for work on patchiness is offered, including a guide to the main literature on the topic. This should, therefore, be a useful stepping-stone for researchers interested in the impact of patchiness on protistan ecology, regardless of the environment.
O. Roger Anderson
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 29-38
https://doi.org/10.4467/16890027AP.13.020.1116Our best evidence is that life arose in the marine environment, and over many millennia of evolutionary proliferation, punctuated by occasional massive extinctions, marine protists have developed remarkably elegant and sometimes complex relationships with prokaryotic and eukaryotic symbionts. Current evidence of the range of marine protist taxa possessing symbionts, including their diversity and physiological functional relationships, is reviewed within an ecological context. Some perspectives are presented on potential opportunities for new avenues of research in unraveling the remarkable adaptive value of two or more genetically diverse marine unicellular organisms living in a close structural and physiological relationship.
Myung Gil Park, Miran Kim, Sunju Kim
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 39-50
https://doi.org/10.4467/16890027AP.14.005.1442Several dinoflagellates are known to practice acquired phototrophy by either hosting intact algal endosymbionts or retaining plastids. The acquisition of phototrophy in dinoflagellates appears to occur independently over a variety of orders, rather than being restricted to any specific order(s). While dinoflagellates with intact algal cells host endosymbionts of cyanobacteria, pelagophyte, prasinophyte or dictyochophyte, most organelle-retaining dinoflagellates acquire plastids from cryptophytes. In dinoflagellates with acquired phototrophy, the mechanism by which symbionts or plastids are obtained has not been well studied at sub-cellular or ultrastructural level, and thus little is known regarding their mechanism to sequester and maintain photosynthetic structures, except for three cases, Amphidinium poecilochroum, Gymnodinium aeruginosum, and Dinophysis caudata with peduncle feeding. Dinoflagellates with acquired phototrophy display different degrees of reduction of the retained endosymbiont and organelles, ranging from those which contain intact whole algal cells (e.g. green Noctiluca scintillans), to those which have retained almost a full complement of organelles (e.g., Amphidinium poecilochroum and Podolampas bipes), to those in which only the plastids remain (e.g., Amphidinium wigrense and Dinophysis spp.). A series of events leading to acquisition and subsequent degeneration of a whole-cell endosymbiont have been widely recognized as evolutionary pathway of the acquisition of plastids. However, recent work on D. caudata suggests that acquisition of phototrophy by predation (i.e. kleptoplastidy) may be a mechanism and evolutionary pathway through which plastids originated in dinoflagellates with ‘foreign’ plastids other than the ‘typical’ peridinin-type plastids. Most organelle-retaining dinoflagellates are facultative mixotrophs, with Dinophysis species and an undescribed Antarctic dinoflagellate being the only obligate mixotrophs known so far. The establishment of dinoflagellates with acquired phototrophy in cultures and careful research using the cultures would help improve our knowledge of the evolution of the dinoflagellate plastids and their ecophysiology.
Alf Skovgaard
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 51-62
https://doi.org/10.4467/16890027AP.14.006.1443Parasitism is an immensely successful mode of nutrition and parasitic organisms are abundant in most ecosystems. This is also the case for marine planktonic ecosystems in which a large variety of parasitic species are known. Most of these parasites are protists and they infect a wide range of hosts from the marine plankton, ranging from other protists to larger planktonic invertebrates. Parasites often have morphologies and life cycles that are highly specialized as compared to their free-living relatives. However, this does not mean that parasites are necessarily odd or rare phenomena; on the contrary parasites constitute numerically and ecologically important components of the ecosystem. This review gives an overview of the existing knowledge on the diversity and occurrence of parasitic protists in the marine plankton and examines the available information on the potential effects and role of parasitism in this ecosystem. Importance is given to the fact that prevalence and impact of parasitic organisms in marine planktonic systems appear to be overwhelmingly understudied.
Fernando Gómez
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 63-75
https://doi.org/10.4467/16890027AP.13.021.1118Dinoflagellates (Alveolata, Dinophyceae) are protists with a truly remarkable diversity in lifestyles (free-living, parasites and mutualistic symbionts), habitats (marine, freshwater, plankton, benthos), and trophic modes (heterotrophic, plastid-containing). Here dinoflagellates are used to evaluate biases in the availability of molecular markers in relation to the variety of functional and ecological characteristics of protists. A large number of dinoflagellate sequences are available in GenBank, at least one for 56% of the 264 described genera. The most common marker is the small ribosomal subunit ribosomal DNA (49%). At the species level, SSU rDNA or the large subunit rDNA are available for 15% of the 2,386 described species. Availability of sequences of the internal transcribed spacers (ITS) and cytochrome oxidase I (COI) show a strong bias towards cultivable species. Relative to trophic mode, while about half of the known dinoflagellates are heterotrophic, only 12% of them have been sequenced compared to 29% of the plastid-containing species. For the COI marker availability is 10 times greater for plastid-containing compared to heterotrophic species. Freshwater species are underrepresented (13%) relative to the marine forms (22%). A high proportion of benthic species have been sequenced (46%) reflecting interest in Symbiodinium and harmful epiphytic taxa. Most of the relatively few described mutualistic species have been sequenced (> 80%). In contrast, only 17% of the described parasitic species have been sequenced, and most of the available sequences were not identified at the species level. In recent years, new species have been described mostly from coastal blooms or cultures. These studies are favored by the availability of abundant material for detailed studies of ultrastructure and multi-gene molecular phylogenies. Many methods are difficult to apply for the scarce specimens available from the open ocean. The requirement of these protocols, easy to apply with cultured species, is an obstacle in our knowledge of the open ocean diversity because it discourages studies based on sparse material. Consequently, in recent years descriptions of new species from the open ocean have declined considerably.
Sabine Agatha, Michaela C. Strüder-Kypke
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 77-90
https://doi.org/10.4467/16890027AP.14.008.1445The evolution of the dominant marine plankton ciliates, the oligotrichids and choreotrichids, is analysed for morphologic and genetic convergences and apomorphies based on literature and our own data. These findings have taxonomic implications. Within the oligotrichid genus Parallelostrombidium two subgenera, Parallelostrombidium Agatha, 2004 nov. stat. and Asymptokinetum nov. subgen., are established, using the courses of the ventral and girdle kineties as a distinguishing feature. Likewise, a different arrangement of extrusome attachment sites is used for a split of the oligotrichid genus Novistrombidium into the subgenera Novistrombidium Song and Bradbury, 1998 nov. stat. and Propecingulum nov. subgen.; Novistrombidium (Propecingulum) ioanum (Lynn and Gilron, 1993) nov. comb. and Novistrombidium (Propecingulum) platum (Song and Packroff, 1997) nov. comb. are affiliated. Based on discrepancies in the somatic ciliary pattern and the presence of conspicuous argyrophilic inclusions, the aloricate choreotrichid species Pelagostrobilidium kimae nov. spec. is distinguished from P. conicum. The diagnosis for the tintinnid family Eutintinnidae Bachy et al., 2012 is improved by including cell features. The co-operation of taxonomists and molecular biologists is strongly recommended to prevent misinterpretations of gene trees due to incorrectly identified species and for better species circumscriptions.
Connie Lovejoy
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 91-100
https://doi.org/10.4467/16890027AP.14.009.1446Advances in sequencing technology and the environmental genomic approaches have brought attention to the vastness of protist biodiversity. While over much of the world’s oceans the species and phylotypes making up this diversity are assumed to be something previously hidden and now revealed, the recent rapid changes in the Arctic mean that such assumptions may be a simplification. Historical morphological species data can be used to validate new records provided that more of these species are identified using standard molecular markers. Environmental surveys can also go further by identifying species over regions, seasons and depths. High throughput sequencing and bioinformatics tools provide a means of monitoring and eventually predicting the consequences of change. We give an example of how microbial eukaryote communities differ over pan-arctic scales, emphasizing the need for additional sampling and the need for caution in extrapolating the results of one region to the entire Arctic.
John R. Dolan, Eun Jin Yang, Tae Wan Kim, Sung-Ho Kang
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 101-113
https://doi.org/10.4467/16890027AP.14.010.1447The Chukchi Sea was sampled in August of 2011, a year of near-normal sea ice among recent years, and again in August 2012, a year of all time record low sea ice. We exploited this sampling to test the hypothesis that different sea ice conditions are associated with differences in abundances or species composition of microzooplankton through an examination of tintinnids and radiolarians. From 18 stations in 2011, and 19 stations in 2012, organisms were enumerated in plankton net tow material, and chlorophyll determinations made (total and ≤ 20 μm) from discrete depth samples. We found that the low sea ice conditions of 2012 were associated with higher chlorophyll concentrations (both total and the ≤ 20 μm size fraction), compared to 2011. However, tintinnid ciliates and radiolarians were much lower in concentration, by about an order of magnitude, compared to 2011. In both years the radiolarian assemblage was dominated by Amphiselma setosa. The species composition of the tintinnid ciliates was similar in the two years, but there were distinct differences in the relative abundances of certain species. The 2012, low sea ice assemblage, was dominated by small forms in contrast to 2011, when large species were the most abundant. We present these findings in detail and discuss possible explanations for the apparent differences in the microzooplankton communities associated with distinct sea ice conditions in the Chukchi Sea.
David J. Patterson
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 115-128
https://doi.org/10.4467/16890027AP.14.011.1448The ‘big new biology’ is a vision of a discipline transformed by a commitment to sharing data and with investigative practices that call on very large open pools of freely accessible data. As this datacentric world matures, biologists will be better able to manage the deluge of data arising from digitization programs, governmental mandates for data sharing, and increasing instrumentation of science. The big new biology will create new opportunities for research and will enable scientists to answer questions that require access to data on a scale not previously possible. Informatics will become the new genomics, and those not participating will become marginalized. If a traditional discipline like protistology is to benefit from this big data world, it must define, build, and populate an appropriate infrastructure. The infrastructure is likely to be modular, with modules focusing on needs within defined subject and makes it available in standard formats by an array of pathways. It is the responsibility of protistologists to build such nodes for their own discipline.
Keith Davidson
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 129-138
https://doi.org/10.4467/16890027AP.14.012.1449Protists are key components of marine microbial communities and hence of the biogeochemical mathematical models that are used to study the interaction between organisms, and the associated cycling of carbon and other nutrients. With increased computing power, models of microbial communities have markedly increased in complexity in the last 20 years, from relatively simple single nutrient currency, nutrient-phytoplankton-zooplankton-detritus (NPZD) models to plankton functional type (PFT) or trait based models of multiple organisms, or individual based models (IBMs) of specific organisms. However, our recognition, if not parameterisation, of the physiological processes that underpin both autotrophic and heterotrophic protist nutrition and growth arguably have increased faster than our modelling capability, generating a wealth of new modelling challenges. This paper therefore reviews historical development, current capability, and the future directions and challenges in protist based mathematical modelling.
David J. S. Montagnes, John R. Dolan
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 1-2
https://doi.org/10.4467/16890027AP.14.001.1438The Chukchi Sea was sampled in August of 2011, a year of near-normal sea ice among recent years, and again in August 2012, a year of all time record low sea ice. We exploited this sampling to test the hypothesis that different sea ice conditions are associated with differences in abundances or species composition of microzooplankton through an examination of tintinnids and radiolarians. From 18 stations in 2011, and 19 stations in 2012, organisms were enumerated in plankton net tow material, and chlorophyll determinations made (total and ≤ 20 µm) from discrete depth samples. We found that the low sea ice conditions of 2012 were associated with higher chlorophyll concentrations (both total and the ≤ 20 µm size fraction), compared to 2011. However, tintinnid ciliates and radiolarians were much lower in concentration, by about an order of magnitude, compared to 2011. In both years the radiolarian assemblage was dominated by Amphiselma setosa. The species composition of the tintinnid ciliates was similar in the two years, but there were distinct differences in the relative abundances of certain species. The 2012, low sea ice assemblage, was dominated by small forms in contrast to 2011, when large species were the most abundant. We present these findings in detail and discuss possible explanations for the apparent differences in the microzooplankton communities associated with distinct sea ice conditions in the Chukchi Sea
Tom Fenchel
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 3-12
https://doi.org/10.4467/16890027AP.13.019.1117Aerobic protozoa can maintain fully aerobic metabolic rates even at very low O2-tensions; this is related to their small sizes. Many – or perhaps all – protozoa show particular preferences for a given range of O2-tensions. The reasons for this and the role for their distribution in nature are discussed and examples of protozoan biota in O2-gradients in aquatic systems are presented. Facultative anaerobes capable of both aerobic and anaerobic growth are probably common within several protozoan taxa. It is concluded that further progress in this area is contingent on physiological studies of phenotypes.
Celia Bulit
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 13-27
https://doi.org/10.4467/16890027AP.14.003.1440Analysing the spatio-temporal distribution of protistan microplankton has faced both conceptual and technical difficulties. However, recognition of a need to study planktonic patchiness, application of a major geology-based methodology (geostatistics) to ecology, and advances in computational technologies have widened the interest in this topic and made it more assessable. This review provides methodological and conceptual guidance on the application of geostatistics to microplankton analysis, using ciliates as example model organisms. Applying geostatistical analysis (and complementary methodologies) to the distribution of ciliate and phytoplankton reveals that attributes of their populations and assemblages (e.g. abundance, biomass, production, diversity) are patchily distributed at multiple spatial-scales in different aquatic environments, and these change over time. Data examined from several environments and scales exhibit distinct patterns of patches regarding their shape, density, and structure; these data can then be used to suggest a behavioural niche-separation of ciliates and the influence of patchiness on the rate processes of food webs. Throughout the review, basic guidance is provided for interpreting where, when, and why planktonic ciliate are so distributed, and directions for work on patchiness is offered, including a guide to the main literature on the topic. This should, therefore, be a useful stepping-stone for researchers interested in the impact of patchiness on protistan ecology, regardless of the environment.
O. Roger Anderson
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 29-38
https://doi.org/10.4467/16890027AP.13.020.1116Our best evidence is that life arose in the marine environment, and over many millennia of evolutionary proliferation, punctuated by occasional massive extinctions, marine protists have developed remarkably elegant and sometimes complex relationships with prokaryotic and eukaryotic symbionts. Current evidence of the range of marine protist taxa possessing symbionts, including their diversity and physiological functional relationships, is reviewed within an ecological context. Some perspectives are presented on potential opportunities for new avenues of research in unraveling the remarkable adaptive value of two or more genetically diverse marine unicellular organisms living in a close structural and physiological relationship.
Myung Gil Park, Miran Kim, Sunju Kim
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 39-50
https://doi.org/10.4467/16890027AP.14.005.1442Several dinoflagellates are known to practice acquired phototrophy by either hosting intact algal endosymbionts or retaining plastids. The acquisition of phototrophy in dinoflagellates appears to occur independently over a variety of orders, rather than being restricted to any specific order(s). While dinoflagellates with intact algal cells host endosymbionts of cyanobacteria, pelagophyte, prasinophyte or dictyochophyte, most organelle-retaining dinoflagellates acquire plastids from cryptophytes. In dinoflagellates with acquired phototrophy, the mechanism by which symbionts or plastids are obtained has not been well studied at sub-cellular or ultrastructural level, and thus little is known regarding their mechanism to sequester and maintain photosynthetic structures, except for three cases, Amphidinium poecilochroum, Gymnodinium aeruginosum, and Dinophysis caudata with peduncle feeding. Dinoflagellates with acquired phototrophy display different degrees of reduction of the retained endosymbiont and organelles, ranging from those which contain intact whole algal cells (e.g. green Noctiluca scintillans), to those which have retained almost a full complement of organelles (e.g., Amphidinium poecilochroum and Podolampas bipes), to those in which only the plastids remain (e.g., Amphidinium wigrense and Dinophysis spp.). A series of events leading to acquisition and subsequent degeneration of a whole-cell endosymbiont have been widely recognized as evolutionary pathway of the acquisition of plastids. However, recent work on D. caudata suggests that acquisition of phototrophy by predation (i.e. kleptoplastidy) may be a mechanism and evolutionary pathway through which plastids originated in dinoflagellates with ‘foreign’ plastids other than the ‘typical’ peridinin-type plastids. Most organelle-retaining dinoflagellates are facultative mixotrophs, with Dinophysis species and an undescribed Antarctic dinoflagellate being the only obligate mixotrophs known so far. The establishment of dinoflagellates with acquired phototrophy in cultures and careful research using the cultures would help improve our knowledge of the evolution of the dinoflagellate plastids and their ecophysiology.
Alf Skovgaard
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 51-62
https://doi.org/10.4467/16890027AP.14.006.1443Parasitism is an immensely successful mode of nutrition and parasitic organisms are abundant in most ecosystems. This is also the case for marine planktonic ecosystems in which a large variety of parasitic species are known. Most of these parasites are protists and they infect a wide range of hosts from the marine plankton, ranging from other protists to larger planktonic invertebrates. Parasites often have morphologies and life cycles that are highly specialized as compared to their free-living relatives. However, this does not mean that parasites are necessarily odd or rare phenomena; on the contrary parasites constitute numerically and ecologically important components of the ecosystem. This review gives an overview of the existing knowledge on the diversity and occurrence of parasitic protists in the marine plankton and examines the available information on the potential effects and role of parasitism in this ecosystem. Importance is given to the fact that prevalence and impact of parasitic organisms in marine planktonic systems appear to be overwhelmingly understudied.
Fernando Gómez
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 63-75
https://doi.org/10.4467/16890027AP.13.021.1118Dinoflagellates (Alveolata, Dinophyceae) are protists with a truly remarkable diversity in lifestyles (free-living, parasites and mutualistic symbionts), habitats (marine, freshwater, plankton, benthos), and trophic modes (heterotrophic, plastid-containing). Here dinoflagellates are used to evaluate biases in the availability of molecular markers in relation to the variety of functional and ecological characteristics of protists. A large number of dinoflagellate sequences are available in GenBank, at least one for 56% of the 264 described genera. The most common marker is the small ribosomal subunit ribosomal DNA (49%). At the species level, SSU rDNA or the large subunit rDNA are available for 15% of the 2,386 described species. Availability of sequences of the internal transcribed spacers (ITS) and cytochrome oxidase I (COI) show a strong bias towards cultivable species. Relative to trophic mode, while about half of the known dinoflagellates are heterotrophic, only 12% of them have been sequenced compared to 29% of the plastid-containing species. For the COI marker availability is 10 times greater for plastid-containing compared to heterotrophic species. Freshwater species are underrepresented (13%) relative to the marine forms (22%). A high proportion of benthic species have been sequenced (46%) reflecting interest in Symbiodinium and harmful epiphytic taxa. Most of the relatively few described mutualistic species have been sequenced (> 80%). In contrast, only 17% of the described parasitic species have been sequenced, and most of the available sequences were not identified at the species level. In recent years, new species have been described mostly from coastal blooms or cultures. These studies are favored by the availability of abundant material for detailed studies of ultrastructure and multi-gene molecular phylogenies. Many methods are difficult to apply for the scarce specimens available from the open ocean. The requirement of these protocols, easy to apply with cultured species, is an obstacle in our knowledge of the open ocean diversity because it discourages studies based on sparse material. Consequently, in recent years descriptions of new species from the open ocean have declined considerably.
Sabine Agatha, Michaela C. Strüder-Kypke
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 77-90
https://doi.org/10.4467/16890027AP.14.008.1445The evolution of the dominant marine plankton ciliates, the oligotrichids and choreotrichids, is analysed for morphologic and genetic convergences and apomorphies based on literature and our own data. These findings have taxonomic implications. Within the oligotrichid genus Parallelostrombidium two subgenera, Parallelostrombidium Agatha, 2004 nov. stat. and Asymptokinetum nov. subgen., are established, using the courses of the ventral and girdle kineties as a distinguishing feature. Likewise, a different arrangement of extrusome attachment sites is used for a split of the oligotrichid genus Novistrombidium into the subgenera Novistrombidium Song and Bradbury, 1998 nov. stat. and Propecingulum nov. subgen.; Novistrombidium (Propecingulum) ioanum (Lynn and Gilron, 1993) nov. comb. and Novistrombidium (Propecingulum) platum (Song and Packroff, 1997) nov. comb. are affiliated. Based on discrepancies in the somatic ciliary pattern and the presence of conspicuous argyrophilic inclusions, the aloricate choreotrichid species Pelagostrobilidium kimae nov. spec. is distinguished from P. conicum. The diagnosis for the tintinnid family Eutintinnidae Bachy et al., 2012 is improved by including cell features. The co-operation of taxonomists and molecular biologists is strongly recommended to prevent misinterpretations of gene trees due to incorrectly identified species and for better species circumscriptions.
Connie Lovejoy
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 91-100
https://doi.org/10.4467/16890027AP.14.009.1446Advances in sequencing technology and the environmental genomic approaches have brought attention to the vastness of protist biodiversity. While over much of the world’s oceans the species and phylotypes making up this diversity are assumed to be something previously hidden and now revealed, the recent rapid changes in the Arctic mean that such assumptions may be a simplification. Historical morphological species data can be used to validate new records provided that more of these species are identified using standard molecular markers. Environmental surveys can also go further by identifying species over regions, seasons and depths. High throughput sequencing and bioinformatics tools provide a means of monitoring and eventually predicting the consequences of change. We give an example of how microbial eukaryote communities differ over pan-arctic scales, emphasizing the need for additional sampling and the need for caution in extrapolating the results of one region to the entire Arctic.
John R. Dolan, Eun Jin Yang, Tae Wan Kim, Sung-Ho Kang
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 101-113
https://doi.org/10.4467/16890027AP.14.010.1447The Chukchi Sea was sampled in August of 2011, a year of near-normal sea ice among recent years, and again in August 2012, a year of all time record low sea ice. We exploited this sampling to test the hypothesis that different sea ice conditions are associated with differences in abundances or species composition of microzooplankton through an examination of tintinnids and radiolarians. From 18 stations in 2011, and 19 stations in 2012, organisms were enumerated in plankton net tow material, and chlorophyll determinations made (total and ≤ 20 μm) from discrete depth samples. We found that the low sea ice conditions of 2012 were associated with higher chlorophyll concentrations (both total and the ≤ 20 μm size fraction), compared to 2011. However, tintinnid ciliates and radiolarians were much lower in concentration, by about an order of magnitude, compared to 2011. In both years the radiolarian assemblage was dominated by Amphiselma setosa. The species composition of the tintinnid ciliates was similar in the two years, but there were distinct differences in the relative abundances of certain species. The 2012, low sea ice assemblage, was dominated by small forms in contrast to 2011, when large species were the most abundant. We present these findings in detail and discuss possible explanations for the apparent differences in the microzooplankton communities associated with distinct sea ice conditions in the Chukchi Sea.
David J. Patterson
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 115-128
https://doi.org/10.4467/16890027AP.14.011.1448The ‘big new biology’ is a vision of a discipline transformed by a commitment to sharing data and with investigative practices that call on very large open pools of freely accessible data. As this datacentric world matures, biologists will be better able to manage the deluge of data arising from digitization programs, governmental mandates for data sharing, and increasing instrumentation of science. The big new biology will create new opportunities for research and will enable scientists to answer questions that require access to data on a scale not previously possible. Informatics will become the new genomics, and those not participating will become marginalized. If a traditional discipline like protistology is to benefit from this big data world, it must define, build, and populate an appropriate infrastructure. The infrastructure is likely to be modular, with modules focusing on needs within defined subject and makes it available in standard formats by an array of pathways. It is the responsibility of protistologists to build such nodes for their own discipline.
Keith Davidson
Acta Protozoologica, Volume 53, Issue 1, 2014, pp. 129-138
https://doi.org/10.4467/16890027AP.14.012.1449Protists are key components of marine microbial communities and hence of the biogeochemical mathematical models that are used to study the interaction between organisms, and the associated cycling of carbon and other nutrients. With increased computing power, models of microbial communities have markedly increased in complexity in the last 20 years, from relatively simple single nutrient currency, nutrient-phytoplankton-zooplankton-detritus (NPZD) models to plankton functional type (PFT) or trait based models of multiple organisms, or individual based models (IBMs) of specific organisms. However, our recognition, if not parameterisation, of the physiological processes that underpin both autotrophic and heterotrophic protist nutrition and growth arguably have increased faster than our modelling capability, generating a wealth of new modelling challenges. This paper therefore reviews historical development, current capability, and the future directions and challenges in protist based mathematical modelling.
Publication date: 28.01.2014
Editor-in-Chief: Krzysztof Wiąckowski
Acta Protozoologica - International Journal on Protistology - is a quarterly journal that publishes current and comprehensive, experimental, and theoretical contributions across the breadth of protistology, and cell biology of Eukaryote microorganisms including: behaviour, biochemistry and molecular biology, development, ecology, genetics, parasitology, physiology, photobiology, systematics and phylogeny, and ultrastructure. It publishes original research reports, critical reviews of current research written by invited experts in the field, short communications, book reviews, and letters to the Editor.
O. Roger Anderson, Krista McGuire
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 217-227
https://doi.org/10.4467/16890027AP.14.002.1439The ecology of tundra terrestrial environments has gained increasing attention due to potential major changes resulting from global warming and climate change. However, the composition of terrestrial microbial communities and their role in the biogeochemical carbon cycle are less well studied. This is the first report of the C-biomass of bacteria, fungi, and representative protozoa (heterotrophic nanoflagellates, naked amoebae, and testate amoebae) in Alaskan tundra soil samples, and the effects of glucose solution enrichment in laboratory studies simulating release of soluble organic compounds as may occur during permafrost melt and increased plant root exudates due to global warming. The data for three moss-rich surface samples, two in spring and one in summer (2011), are reported for C-supplemented (8,000 μg glucose-C) and non-supplemented treatments in laboratory culture. Seven days after supplementation, fungal C-biomass in the glucose-treated and untreated samples were similar in the range of 5 to 11 mg g–1 soil dry weight, the highest values in the summer samples. The bacterial C-biomass was the next highest in the range of 20 to 120 μg g–1 soil dry weight, followed by heterotrophic nanoflagellates (2 to 14 μg g–1 soil dry weight). The naked amoebae (0.13 to 0.94 μg C g–1 soil dry weight) and testate amoebae (2 to 20 ng C g–1 soil dry weight) contributed the least C-biomass. All of the bacterial and protozoan treatments showed increased biomass with glucose supplementation. Based on size, and C-biomass estimates, the phagotrophic protozoa appear to be organized in a classical bacterial-based trophic hierarchy (i.e. bacteria – nanoflagellates – naked amoebae – testate amoebae, in ascending order). Correlations of the C-biomass of bacteria to each of the protozoa, provided further evidence of a trophic pyramid; bacteria vs. nanoflagellates (r = –0.986), indicating top-down control by predatory flagellates, bacteria vs. naked amoebae (r = –0.361) and bacteria vs. testate amoebae (r = –0.131), each of decreasing magnitude as would be predicted for higher level consumers. Estimates of bacterial predation indicated strong predatory pressures on bacteria by the protozoa, greater with C-supplementation compared to the non-supplemented treatments.
Vasily V. Zlatogursky
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 229-236
https://doi.org/10.4467/16890027AP.14.004.1441The cell body of centrohelid heliozoans is covered with a layer of scales. These scales have species-specific morphology and, since they present in the trophic stage of the cell cycle can be termed “trophic” scales. Several species are known to form cysts; during this process they can produce specific “cyst” scales, different from trophic scales. The present paper describes morphology of cyst scales in two species of centrohelid heliozoans: Raineriophrys erinaceoides and Raphidiophrys heterophryoidea. The latter species has two types of cyst scales: scales of the first type resemble trophic scales in general structure but, their borders are broad, flattened and not enrolled. Scales of the second type are polygonal and connected to each other by special teeth, forming a single layer organized in a jig-saw puzzle-like manner. In Raineriophrys erinaceoides only one type of cyst scale was found. These scales are polygonal and completely different from trophic scales. It is unclear whether these scales form a puzzle-like layer or just overlap each other. Newly excysted individuals keep remnants of cyst scales in their cell coverings and at this stage cyst scales can easily be noted. The morphology of the cyst scales reported here is unlike any other previously reported.
Helge Abildhauge Thomsen, Jette Buch Østergaard, Mikal Heldal
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 237-256
https://doi.org/10.4467/16890027AP.14.007.1444A contingent of weakly calcified coccolithophorid genera and species were described from polar regions almost 40 years ago. In the interim period a few additional findings have been reported enlarging the realm of some of the species. The genus Wigwamma is revisited here with the purpose of providing, based on additional sampling from both polar regions, an update on species morphology, life history events and biogeography that can serve as a reference for the future. A new genus, Pseudowigwamma gen. nov. is described to accommodate Wigwamma scenozonion, a species which critically deviates from a core group of five Wigwamma species in terms of coccolith morphology and life history events. Wigwamma armatura sp. nov. is described on the basis of material from the Weddell Sea, Antarctica. While fitting nicely into the Wigwamma generic concept, the species adds new dimensions to the overall appearance of the coccolith armour of the cell.
Ewa Przyboś, Sebastian Tarcz, Marta Surmacz, Natalia Sawka, Sergei I. Fokin
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 257-266
https://doi.org/10.4467/16890027AP.13.022.1314New stands of Paramecium tredecaurelia, a rare species of the P. aurelia spp. complex, were identified in Thailand and Madagascar on the basis of mating reactions and molecular markers (rDNA and mtDNA). Analysis of DNA fragments showed that all P. tredecaurelia strains, the recently recorded ones and the ones known previously from France, Mexico, and Israel, form a monophyletic and well-defined clade in the P. aurelia species trees. All of these strains, collected from different localities around the world, represent identical or nearly identical haplotypes in terms of all the studied DNA fragments. Given the huge distances between particular collection sites, such a low level of variability of the studied sequences may result from a slow rate of evolution in P. tredecaurelia.
Saleh Al-Quraishy, Abdel-Azeem S. Abdel-Baki, Mamdooh S. A. AL Otaibi
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 267-272
https://doi.org/10.4467/16890027AP.13.024.1315Choleoeimeria bunopusi sp. n. is described from the gall bladder of the tuberculated gecko Bunopus tuberculatus in Saudi Arabia. The prevalence of infection was 13.3% (2/15). Oocysts were ellipsoidal and measured 31 (30–33) × 21 (20–22) μm. Sporocysts were dizoic, elliptical in shape and measured 12 (11–13) × 7 (6–8) μm. The endogenous development was confined to the gall bladder epithelium. The hypertrophic parasitized biliary epithelium either remained in one layer or became stratified. Meronts, gamonts, and young oocysts were detected.
Daniele Corsaro, Julia Walochnik, Danielle Venditti, Karl-Dieter Müller, Rolf Michel
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 273-281
https://doi.org/10.4467/16890027AP.13.025.1316A thermophilic strain of Naegleria clarki, isolated from a pond, has previously been investigated for its peculiarity to host a cytoplasmic symbiont, which causes a loss of the ability to form cysts. This endosymbiont, called Pcb, was itself infected by a phage, and exhibited chlamydia-like features resembling to another symbiont of Naegleria previously described as Protochlamydia naegleriophila. We report in this study, the results of amoeba host range and 16S rDNA molecular phylogeny of this strain, showing that Pcb is a new strain of the Naegleria endosymbiont chlamydial species Protochlamydia naegleriophila (Chlamydiae: Parachlamydiaceae).
Lúcio André Viana, Adarene Guimarães da Silva Motta, Marcos Eduardo Coutinho, Carlos Frederico Duarte Rocha
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 283-289
https://doi.org/10.4467/16890027AP.13.026.1317During November 2011, faeces from 23 black caimans (Melanosuchus niger) were collected from the Brazilian Amazon, and coccidians were found in 83% of the individuals examined. Three Eimeria species were found in the black caiman faeces, two of which were recognised as new species and are subsequently described in the present study. Eimeria paraguayensis was found in 17 of 23 animals sampled. Eimeria nigeri n. sp were found in 16/23 animals examined. Oocysts were spherical to sub-spherical, 29.2 × 28.1 (23–32 × 23–30) μm, and 12.1 × 11.0 μm spherical oocyst residuum was present. Sporocyst was ovoid, 15.5 × 9.7 (8–11 × 12–17) μm, and had a Stieda body at a slightly pointed end. The sporocyst residuum consisted of a compact mass of refractile granules. Eimeria portovelhensis n. sp. were found in 16/23 animals examined. Oocysts were spheroidal, 19.5 × 19.1 (16–21) μm, and had 9.0 × 7.8 μm spherical oocyst residuum present. The spindle-shaped sporocysts were 11.0 × 4.0 (8–13 × 2–5) μm and had two apparent Stieda bodies, one at each pole and with one filament curved at each pole. Sporocyst residuum was present, with four or five small refractile granules. The two new species are differentiated from the five species of Eimeria recorded within the crocodilian family Alligatoridae.
Kenny Contreras, Matías J. Cafaro
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 291-297
https://doi.org/10.4467/16890027AP.13.027.1318Symbiosis is the association between two non-related organisms. The common yellow-banded millipede, Anadenobolus monilicornis (Diplopoda: Spirobolida: Rhinocricidae) and the protist Enterobryus luteovirgatus sp. nov. (Ichthyosporea: Eccrinales), a species of hair-like microorganism that inhabits its gut, form a commensalistic relationship. The genus Enterobryus was once part of a fungal class (Trichomycetes), but now it is classified as a protist. Other Enterobryus species have been reported associated with non-carnivorous arthropod hosts including beetles, crabs and millipedes. Yellow-banded millipedes from Guanica Dry Forest, Puerto Rico were collected to study the prevalence of Enterobryus species. A new Enterobryus species that inhabits A. monilicornis is herein described. Traditionally, Enterobryus species are difficult to identify due to high intraspecific variation. Thus, statistical analysis of character measurements is included in an attempt to investigate character stability. Millipedes were dissected; gut linings with attached Enterobryus were placed on slides and preserved. Morphometric data of thalli, sporangiospores and holdfasts presented a normal distribution of parameters except for the basal disk width of the holdfast, which showed extreme variation. This character, although used to described Enterobryus species is not reliable in E. luteovirgatus when using the mean or range values in taxon descriptions.
Julia M. Malysh, Yuri S. Tokarev, Natalia V. Sitnicova, Vyacheslav V. Martemyanov, Andrei N. Frolov, Irma V. Issi
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 299-308
https://doi.org/10.4467/16890027AP.13.028.1319Adults of beet webworm Loxostege sticticalis were collected in Western Siberia in 2009 and 2010. A microsporidium was found infecting 12 of 50 moths in 2010. The parasite develops in direct contact with host cell cytoplasm, sporogony is presumably disporoblastic. The spores are ovoid, diplokaryotic, 4.2 × 2.4 μm in size (fresh), without a sporophorous vesicle. Electron microscopy showed: (a) tubules on the surface of sporoblasts and immature spores; (b) slightly anisofilar polar tube with 10–14 coils, last 2–3 coils of lesser electron density; (c) bipartite polaroplast with anterior and posterior parts composed of thin and thick lamellae, respectively; (d) an indentation in the region of the anchoring disc; (e) an additional layer of electron-dense amorphous matter on the exospore surface. The spore ultrastructure is characteristic of the genus Tubulinosema. Sequencing of small subunit and large subunit ribosomal RNA genes showed 98–99.6% similarity of this parasite to the Tubulinosema species available on Genbank. A new species Tubulinosema loxostegi sp. n. is established.
Daniele Corsaro, Danielle Venditti
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 309-316
https://doi.org/10.4467/16890027AP.13.029.1320Some amoebae were recovered from freshwater samples on agar plates. Due to a fungal contamination tightly associated with these amoebae, it was impossible to correctly characterize them on a morphological base, but sequences of the small subunit ribosomal RNA gene (SSU rDNA) were successfully obtained from three strains. Phylogenetic analysis performed on these SSU rDNA allowed to identify these amoebae as members of a new lineage, related to the Dermamoebida, which includes also several other environmental SSU sequences.
Nikhil Buduma, Jenny Balabanian, Pranati Dalvi, Soo-Khee Chia, Ashreet Dhaliwal, Dany Eliya, John Boothby, Shannon Bros-Seemann, Ruthann Kibler, Sami Khuri, Sally Veregge
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 317-323
https://doi.org/10.4467/16890027AP.13.029.1321Histamine is a significant biological compound because of its role in mediating the human allergic and inflammatory pathways. Antihistamines are often administered to control the irritating symptoms of allergic reactions. We evaluated phagocytosis in the protist Tetrahymena thermophila for use in screening for potential therapeutic compounds that mimic histamine and antihistamines. Tetrahymena has been frequently used as an experimental model to study compounds for biological effects or to study biological processes. Histamine and the antihistamine diphenhydramine were administered at concentrations ranging from 10–6 μM to 1000 μM, and the corresponding changes in phagocytosis were detected by flow cytometry. Treatment with histamine had no measurable effect on phagocytosis while diphenhydramine decreased phagocytic levels at concentrations above 50 μM. In a competition experiment between histamine and diphenhydramine, histamine did not reverse the dosage-dependent decrease in phagocytosis elicited by diphenhydramine. BLAST searches revealed no significant homologs of the human histamine receptors in T. thermophila. These results suggest that T. thermophila has a receptor for diphenhydramine that is linked to the phagocytic process, but not a histamine receptor. Further study is necessary to elucidate the nature of this previously uninvestigated receptor. The experimental protocol developed as a part of this study may serve as an inexpensive, high throughput, flow cytometric method to screen natural and synthetic compounds for pharmacologically significant properties.
Jacob Lorenzo-Morales, María Valladares, Jaione Sancho, María Reyes-Batllé, Carmen M. Martín-Navarro, Atteneri López-Arencibia, Ana C. González, Luis López-Medina, José E. Piñero, Enrique Martínez-Carretero, Basilio Valladares
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 325-329
https://doi.org/10.4467/16890027AP.13.031.1322The first case of prostatitis in a ten year old mixed breed dog due to Acanthamoeba genotype T4 is reported. The dog was suffering from kidney dysfunction and was admitted for exploration of its organs by echography. All organs were in normal conditions with the exception of the prostate which showed signs of inflammation. An ultrasound-guided puncture was thus performed for further cytological and microbiological study. When the obtained fluid was observed under the microscope, Acanthamoeba trophozoites were detected in a high number. No other pathogens were isolated. Both culture and PCR were positive for Acanthamoeba genus and the isolate was later identified as genotype T4. Unfortunately at this stage, the dog’s owner decided to reject any kind of treatment or therapy. To the best of our knowledge, this is the first report of prostatitis in a dog due to Acanthamoeba genus.
O. Roger Anderson, Krista McGuire
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 217-227
https://doi.org/10.4467/16890027AP.14.002.1439The ecology of tundra terrestrial environments has gained increasing attention due to potential major changes resulting from global warming and climate change. However, the composition of terrestrial microbial communities and their role in the biogeochemical carbon cycle are less well studied. This is the first report of the C-biomass of bacteria, fungi, and representative protozoa (heterotrophic nanoflagellates, naked amoebae, and testate amoebae) in Alaskan tundra soil samples, and the effects of glucose solution enrichment in laboratory studies simulating release of soluble organic compounds as may occur during permafrost melt and increased plant root exudates due to global warming. The data for three moss-rich surface samples, two in spring and one in summer (2011), are reported for C-supplemented (8,000 μg glucose-C) and non-supplemented treatments in laboratory culture. Seven days after supplementation, fungal C-biomass in the glucose-treated and untreated samples were similar in the range of 5 to 11 mg g–1 soil dry weight, the highest values in the summer samples. The bacterial C-biomass was the next highest in the range of 20 to 120 μg g–1 soil dry weight, followed by heterotrophic nanoflagellates (2 to 14 μg g–1 soil dry weight). The naked amoebae (0.13 to 0.94 μg C g–1 soil dry weight) and testate amoebae (2 to 20 ng C g–1 soil dry weight) contributed the least C-biomass. All of the bacterial and protozoan treatments showed increased biomass with glucose supplementation. Based on size, and C-biomass estimates, the phagotrophic protozoa appear to be organized in a classical bacterial-based trophic hierarchy (i.e. bacteria – nanoflagellates – naked amoebae – testate amoebae, in ascending order). Correlations of the C-biomass of bacteria to each of the protozoa, provided further evidence of a trophic pyramid; bacteria vs. nanoflagellates (r = –0.986), indicating top-down control by predatory flagellates, bacteria vs. naked amoebae (r = –0.361) and bacteria vs. testate amoebae (r = –0.131), each of decreasing magnitude as would be predicted for higher level consumers. Estimates of bacterial predation indicated strong predatory pressures on bacteria by the protozoa, greater with C-supplementation compared to the non-supplemented treatments.
Vasily V. Zlatogursky
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 229-236
https://doi.org/10.4467/16890027AP.14.004.1441The cell body of centrohelid heliozoans is covered with a layer of scales. These scales have species-specific morphology and, since they present in the trophic stage of the cell cycle can be termed “trophic” scales. Several species are known to form cysts; during this process they can produce specific “cyst” scales, different from trophic scales. The present paper describes morphology of cyst scales in two species of centrohelid heliozoans: Raineriophrys erinaceoides and Raphidiophrys heterophryoidea. The latter species has two types of cyst scales: scales of the first type resemble trophic scales in general structure but, their borders are broad, flattened and not enrolled. Scales of the second type are polygonal and connected to each other by special teeth, forming a single layer organized in a jig-saw puzzle-like manner. In Raineriophrys erinaceoides only one type of cyst scale was found. These scales are polygonal and completely different from trophic scales. It is unclear whether these scales form a puzzle-like layer or just overlap each other. Newly excysted individuals keep remnants of cyst scales in their cell coverings and at this stage cyst scales can easily be noted. The morphology of the cyst scales reported here is unlike any other previously reported.
Helge Abildhauge Thomsen, Jette Buch Østergaard, Mikal Heldal
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 237-256
https://doi.org/10.4467/16890027AP.14.007.1444A contingent of weakly calcified coccolithophorid genera and species were described from polar regions almost 40 years ago. In the interim period a few additional findings have been reported enlarging the realm of some of the species. The genus Wigwamma is revisited here with the purpose of providing, based on additional sampling from both polar regions, an update on species morphology, life history events and biogeography that can serve as a reference for the future. A new genus, Pseudowigwamma gen. nov. is described to accommodate Wigwamma scenozonion, a species which critically deviates from a core group of five Wigwamma species in terms of coccolith morphology and life history events. Wigwamma armatura sp. nov. is described on the basis of material from the Weddell Sea, Antarctica. While fitting nicely into the Wigwamma generic concept, the species adds new dimensions to the overall appearance of the coccolith armour of the cell.
Ewa Przyboś, Sebastian Tarcz, Marta Surmacz, Natalia Sawka, Sergei I. Fokin
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 257-266
https://doi.org/10.4467/16890027AP.13.022.1314New stands of Paramecium tredecaurelia, a rare species of the P. aurelia spp. complex, were identified in Thailand and Madagascar on the basis of mating reactions and molecular markers (rDNA and mtDNA). Analysis of DNA fragments showed that all P. tredecaurelia strains, the recently recorded ones and the ones known previously from France, Mexico, and Israel, form a monophyletic and well-defined clade in the P. aurelia species trees. All of these strains, collected from different localities around the world, represent identical or nearly identical haplotypes in terms of all the studied DNA fragments. Given the huge distances between particular collection sites, such a low level of variability of the studied sequences may result from a slow rate of evolution in P. tredecaurelia.
Saleh Al-Quraishy, Abdel-Azeem S. Abdel-Baki, Mamdooh S. A. AL Otaibi
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 267-272
https://doi.org/10.4467/16890027AP.13.024.1315Choleoeimeria bunopusi sp. n. is described from the gall bladder of the tuberculated gecko Bunopus tuberculatus in Saudi Arabia. The prevalence of infection was 13.3% (2/15). Oocysts were ellipsoidal and measured 31 (30–33) × 21 (20–22) μm. Sporocysts were dizoic, elliptical in shape and measured 12 (11–13) × 7 (6–8) μm. The endogenous development was confined to the gall bladder epithelium. The hypertrophic parasitized biliary epithelium either remained in one layer or became stratified. Meronts, gamonts, and young oocysts were detected.
Daniele Corsaro, Julia Walochnik, Danielle Venditti, Karl-Dieter Müller, Rolf Michel
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 273-281
https://doi.org/10.4467/16890027AP.13.025.1316A thermophilic strain of Naegleria clarki, isolated from a pond, has previously been investigated for its peculiarity to host a cytoplasmic symbiont, which causes a loss of the ability to form cysts. This endosymbiont, called Pcb, was itself infected by a phage, and exhibited chlamydia-like features resembling to another symbiont of Naegleria previously described as Protochlamydia naegleriophila. We report in this study, the results of amoeba host range and 16S rDNA molecular phylogeny of this strain, showing that Pcb is a new strain of the Naegleria endosymbiont chlamydial species Protochlamydia naegleriophila (Chlamydiae: Parachlamydiaceae).
Lúcio André Viana, Adarene Guimarães da Silva Motta, Marcos Eduardo Coutinho, Carlos Frederico Duarte Rocha
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 283-289
https://doi.org/10.4467/16890027AP.13.026.1317During November 2011, faeces from 23 black caimans (Melanosuchus niger) were collected from the Brazilian Amazon, and coccidians were found in 83% of the individuals examined. Three Eimeria species were found in the black caiman faeces, two of which were recognised as new species and are subsequently described in the present study. Eimeria paraguayensis was found in 17 of 23 animals sampled. Eimeria nigeri n. sp were found in 16/23 animals examined. Oocysts were spherical to sub-spherical, 29.2 × 28.1 (23–32 × 23–30) μm, and 12.1 × 11.0 μm spherical oocyst residuum was present. Sporocyst was ovoid, 15.5 × 9.7 (8–11 × 12–17) μm, and had a Stieda body at a slightly pointed end. The sporocyst residuum consisted of a compact mass of refractile granules. Eimeria portovelhensis n. sp. were found in 16/23 animals examined. Oocysts were spheroidal, 19.5 × 19.1 (16–21) μm, and had 9.0 × 7.8 μm spherical oocyst residuum present. The spindle-shaped sporocysts were 11.0 × 4.0 (8–13 × 2–5) μm and had two apparent Stieda bodies, one at each pole and with one filament curved at each pole. Sporocyst residuum was present, with four or five small refractile granules. The two new species are differentiated from the five species of Eimeria recorded within the crocodilian family Alligatoridae.
Kenny Contreras, Matías J. Cafaro
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 291-297
https://doi.org/10.4467/16890027AP.13.027.1318Symbiosis is the association between two non-related organisms. The common yellow-banded millipede, Anadenobolus monilicornis (Diplopoda: Spirobolida: Rhinocricidae) and the protist Enterobryus luteovirgatus sp. nov. (Ichthyosporea: Eccrinales), a species of hair-like microorganism that inhabits its gut, form a commensalistic relationship. The genus Enterobryus was once part of a fungal class (Trichomycetes), but now it is classified as a protist. Other Enterobryus species have been reported associated with non-carnivorous arthropod hosts including beetles, crabs and millipedes. Yellow-banded millipedes from Guanica Dry Forest, Puerto Rico were collected to study the prevalence of Enterobryus species. A new Enterobryus species that inhabits A. monilicornis is herein described. Traditionally, Enterobryus species are difficult to identify due to high intraspecific variation. Thus, statistical analysis of character measurements is included in an attempt to investigate character stability. Millipedes were dissected; gut linings with attached Enterobryus were placed on slides and preserved. Morphometric data of thalli, sporangiospores and holdfasts presented a normal distribution of parameters except for the basal disk width of the holdfast, which showed extreme variation. This character, although used to described Enterobryus species is not reliable in E. luteovirgatus when using the mean or range values in taxon descriptions.
Julia M. Malysh, Yuri S. Tokarev, Natalia V. Sitnicova, Vyacheslav V. Martemyanov, Andrei N. Frolov, Irma V. Issi
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 299-308
https://doi.org/10.4467/16890027AP.13.028.1319Adults of beet webworm Loxostege sticticalis were collected in Western Siberia in 2009 and 2010. A microsporidium was found infecting 12 of 50 moths in 2010. The parasite develops in direct contact with host cell cytoplasm, sporogony is presumably disporoblastic. The spores are ovoid, diplokaryotic, 4.2 × 2.4 μm in size (fresh), without a sporophorous vesicle. Electron microscopy showed: (a) tubules on the surface of sporoblasts and immature spores; (b) slightly anisofilar polar tube with 10–14 coils, last 2–3 coils of lesser electron density; (c) bipartite polaroplast with anterior and posterior parts composed of thin and thick lamellae, respectively; (d) an indentation in the region of the anchoring disc; (e) an additional layer of electron-dense amorphous matter on the exospore surface. The spore ultrastructure is characteristic of the genus Tubulinosema. Sequencing of small subunit and large subunit ribosomal RNA genes showed 98–99.6% similarity of this parasite to the Tubulinosema species available on Genbank. A new species Tubulinosema loxostegi sp. n. is established.
Daniele Corsaro, Danielle Venditti
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 309-316
https://doi.org/10.4467/16890027AP.13.029.1320Some amoebae were recovered from freshwater samples on agar plates. Due to a fungal contamination tightly associated with these amoebae, it was impossible to correctly characterize them on a morphological base, but sequences of the small subunit ribosomal RNA gene (SSU rDNA) were successfully obtained from three strains. Phylogenetic analysis performed on these SSU rDNA allowed to identify these amoebae as members of a new lineage, related to the Dermamoebida, which includes also several other environmental SSU sequences.
Nikhil Buduma, Jenny Balabanian, Pranati Dalvi, Soo-Khee Chia, Ashreet Dhaliwal, Dany Eliya, John Boothby, Shannon Bros-Seemann, Ruthann Kibler, Sami Khuri, Sally Veregge
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 317-323
https://doi.org/10.4467/16890027AP.13.029.1321Histamine is a significant biological compound because of its role in mediating the human allergic and inflammatory pathways. Antihistamines are often administered to control the irritating symptoms of allergic reactions. We evaluated phagocytosis in the protist Tetrahymena thermophila for use in screening for potential therapeutic compounds that mimic histamine and antihistamines. Tetrahymena has been frequently used as an experimental model to study compounds for biological effects or to study biological processes. Histamine and the antihistamine diphenhydramine were administered at concentrations ranging from 10–6 μM to 1000 μM, and the corresponding changes in phagocytosis were detected by flow cytometry. Treatment with histamine had no measurable effect on phagocytosis while diphenhydramine decreased phagocytic levels at concentrations above 50 μM. In a competition experiment between histamine and diphenhydramine, histamine did not reverse the dosage-dependent decrease in phagocytosis elicited by diphenhydramine. BLAST searches revealed no significant homologs of the human histamine receptors in T. thermophila. These results suggest that T. thermophila has a receptor for diphenhydramine that is linked to the phagocytic process, but not a histamine receptor. Further study is necessary to elucidate the nature of this previously uninvestigated receptor. The experimental protocol developed as a part of this study may serve as an inexpensive, high throughput, flow cytometric method to screen natural and synthetic compounds for pharmacologically significant properties.
Jacob Lorenzo-Morales, María Valladares, Jaione Sancho, María Reyes-Batllé, Carmen M. Martín-Navarro, Atteneri López-Arencibia, Ana C. González, Luis López-Medina, José E. Piñero, Enrique Martínez-Carretero, Basilio Valladares
Acta Protozoologica, Volume 52, Issue 4, 2013, pp. 325-329
https://doi.org/10.4467/16890027AP.13.031.1322The first case of prostatitis in a ten year old mixed breed dog due to Acanthamoeba genotype T4 is reported. The dog was suffering from kidney dysfunction and was admitted for exploration of its organs by echography. All organs were in normal conditions with the exception of the prostate which showed signs of inflammation. An ultrasound-guided puncture was thus performed for further cytological and microbiological study. When the obtained fluid was observed under the microscope, Acanthamoeba trophozoites were detected in a high number. No other pathogens were isolated. Both culture and PCR were positive for Acanthamoeba genus and the isolate was later identified as genotype T4. Unfortunately at this stage, the dog’s owner decided to reject any kind of treatment or therapy. To the best of our knowledge, this is the first report of prostatitis in a dog due to Acanthamoeba genus.
Publication date: 30.07.2013
Editor-in-Chief: Krzysztof Wiąckowski
Richard J. Payne
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 105-113
https://doi.org/10.4467/16890027AP.13.0011.1108To introduce the special issue this paper reviews the use of protists as bioindicators. Seven key advantages of protist bioindicators are highlighted, namely: environmental sensitivity, functional importance, distribution, size and numbers, response times, ease of analysis and preservation potential. Protist bioindicators have been used in a wide range of contexts from ecosystem restoration to fire history, and particularly environmental pollution. Most major protist groups have been used as bioindicators with diatoms, foraminifera and testate amoebae particularly widely studied. To increase uptake of protist bioindication techniques in routine environmental monitoring technique development should consider the needs of stakeholders from an early stage. Papers in this special issue reflect the diversity of both protist life and possible bioindicator applications.
Robert L. Barnett, W. Roland Gehrels, Dan J. Charman, Margot H. Saher, William A. Marshall
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 115-128
https://doi.org/10.4467/16890027AP.13.0012.1109Proxy based sea-level reconstructions are an important tool for defining past patterns of sea-level change and salt-marsh testate amoebae are a newly emerging proxy with high potential as sea-level indicators. This study develops existing analytical techniques concerned with the preparation and counting of testate amoebae for sea-level studies and demonstrates the predictive power of this group of micro-organisms. Two salt marshes in northwestern Norway were sampled for testate amoebae and multiple sub-samples were prepared using different procedures and count totals. Analytical efficiency can be improved upon by using a mild alkali, chemical disaggregant (5% KOH) to break up fibrous, salt-marsh peat and concentrate tests prior to counting. A count total of 100 individuals, rather than 150, can be used to make time gains with little or no loss of taxon information. The Norwegian salt-marsh testate amoebae showed strong zonation relative to tidal elevation. Key indicator taxa from the high marsh included Centropyxis cassis type, Cyclopyxis arcelloides type and Euglypha spp. Those from the low marsh included Difflugia pristis type and a distinctive morphotype of Centropyxis platystoma type. Combined, the two surface data sets from Norway were capable of predicting marsh surface elevations to within ± 0.09 m.
Julie Valentine, Stephen R. Davis, Jason R. Kirby, David M. Wilkinson
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 129-145
https://doi.org/10.4467/16890027AP.13.0013.1110The nature conservation, and wider environmental importance of peatlands, particularly in relation to carbon management, has led to there being a growing interest in attempting to manage degraded peatlands in a way that will restore them to fully functioning peatland ecosystems. Much of this management is concerned with the rewetting of these sites therefore it has become important to monitor the surface wetness of these bogs and if possible compare current wetness with previous, pre-damage, conditions. We present previously unpublished case studies of the use of testate amoebae to monitor bog restoration schemes in N.W. England (Holcroft Moss, Cheshire) and Ireland (Ardagullion Bog, Co. Longford). In addition we summarise the key conservation related conclusions of our previously published work on two other sites in N.W England – Astley Moss (in the Chat Moss complex of Greater Manchester) and Danes Moss (Cheshire). At Holcroft the record of lead pollution from the peat core allows us to date recent changes in the testate community preserved in a peat core and relate these to both conservation management and other changes in the landscape around the bog in over the last 50 years. Ardagullion Bog provides an illustration of the utility of using multiple peat cores in the testate monitoring of peat bog restoration and illustrates that a bog that has only suffered limited ‘damage’ is able to be restored to something close to pre damage conditions on a decadal time scale. We also summarise what we see as the main lessons from testate studies of bog restoration – both from the case studies described in this paper and from the wider literature - and discuss the conditions under which testate amoebae may be of particular use in peatland restoration.
Fabrizio Frontalini, Giulia Margaritelli, Fabio Francescangeli, Roberto Rettori, Eric Armynot Du Châtelet
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 147-160
https://doi.org/10.4467/16890027AP.13.0014.1111The benthic foraminiferal assemblages in Lake Varano (southern Italy) have been investigated in detail. Statistical analyses enable us to recognize two main biotopes and five sub-biotopes that reflect different ecological and environmental conditions. The assemblages mainly seem to be influenced by the hydrological (namely salinity) and sediment conditions in the lake. These biotopes are characterized by specific sub-assemblages and variations in relative species’ abundances. The Outer Lake Biotope is affected by marine influence and is dominated by the foraminiferal species Ammonia beccarii, Ammonia parkinsoniana and Aubignyna perlucida, which are more common in open water environments. In contrast, the Inner-Marginal Lake Biotope reflects more restricted conditions where low salinity values and sand are associated with high numbers of miliolids. These two main biotopes are thus subjected to different degrees of confinement and water residence times, both of which are related to the water exchange time of the lake with the Adriatic Sea. In addition five sub-biotopes (Intermediate Marine, Mixing, “Urban”, Marginal, and Innermost) represented by particular foraminiferal assemblages are identified that characterize particular sub-environments. These sub-biotopes are, to some extent, separated by salinity gradients as well as the grain-size and the organic matter of sediments.
Jennifer Garcia, Meryem Mojtahid, Hélène Howa, Elisabeth Michel, Ralf Schiebel, Céline Charbonnier, Pierre Anschutz, Franciscus J. Jorissen
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 161-180
https://doi.org/10.4467/16890027AP.13.0015.1112Benthic and planktic foraminiferal assemblages from two sediment cores (2000 m depth, 44°33′N-2°45′W) were analyzed to first compare modern and dead faunas and next to study changes in the hydrology of the southeastern Bay of Biscay (SE BoB) over the last 12.8 cal ka BP. Considering benthic ecosystem characteristics, the first part of the paleorecord (12.8–7.6 cal ka BP) is composed of laminated sediments that may have resulted from turbiditic overflow events, whereas occurrences of transported species (e.g. Nonionella sp., Cassidulina carinata) attest of continental influence at the core location. After 7.6 cal ka BP, the sediment becomes bioturbated concomitantly to the stabilization of the sea-level. The benthic foraminiferal fauna is largely dominated by Uvigerina peregrina suggesting a high seasonality with seasonal pulsed organic matter fluxes to the seafloor. On the other hand, the planktic foraminiferal composition indicates that surface water masses were under the influence of the polar front in the early record, which retreated at about 11.5 cal ka BP. The early Holocene is characterized by relatively warm and stratified water masses at 8.4–4.8 cal ka BP. The last 4.8 cal ka BP records a gradual sea surface water cooling trend and enhanced foraminiferal production from ~2.6 cal ka BP until present. The early (12.8–10.5 cal ka BP) and late (2.3–1.7 cal ka BP) Holocene are characterized by the presence of the planktic species Globigerinoides ruber probably caused by intrusions of the Iberian Poleward Current (IPC), and a negative state of the North Atlantic Oscillation (NAO).
Anna Sabbatini, Maria Pia Nardelli, Caterina Morigi, Alessandra Negri
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 181-192
https://doi.org/10.4467/16890027AP.13.0016.1113Monothalamous foraminifera with organic and agglutinated test walls (‘‘allogromiids’’ sensu lato) deserve attention because of their importance in deep-sea and shallow-water soft-bottom communities and their crucial phylogenetic position at the base of the foraminiferal evolutionary tree. However, our knowledge of the biodiversity and ecology of monothalamous foraminifera is very incomplete and geographically patchy. Here, we present a short review based on the available data on monothalamous, soft-walled foraminiferal taxa from the Adriatic Sea in response to several environmental parameters (i.e., organic matter, oxygen, grain size, depth). The main results of the studies provide evidence of the importance of these foraminiferal taxa in this shallow, temperate latitude area;they represent a start for the identification of soft-shelled monothalamous morphotypes that could be potential bioindicators of environments influenced by inputs of fresh waters, increasing eutrophication and consequent fluctuations in bottom-water oxygenation. The contribution of this soft-shelled component to living benthic foraminiferal assemblages appears not negligible and excluding it from foraminiferal studies can potentially lead to a loss of ecological information. The study, therefore, provide an atlas of the Adriatic soft-shelled foraminiferal taxa in order to 1) encourage the species-level description, if possible, or alternatively a basic morphotype characterization, 2) facilitate future comparisons of taxa from similar settings, 3) promote their potential use in future biomonitoring investigations together with the hard-shelled foraminifera.
Maria Pia Nardelli, Anna Sabbatini, Alessandra Negri
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 193-202
https://doi.org/10.4467/16890027AP.13.0017.1114Miliolid (calcareous imperforated test) foraminifera have large diffusion all over the world in a wide range of marine environments, but their distributional pattern in relation to heavy metal pollution is not clearly understood yet. The aim of this study was to better understand the biological response of the miliolid species Pseudotriloculina rotunda to experimental chronic exposure at several zinc concentrations. The duration of the experiment was 10 weeks, and six different concentrations of zinc were tested between 0 and 100 mg/L. Increasing zinc concentrations led to increasing delay or to complete cease of the new chambers’ construction, with consequences on growth rates and affected vitality and biomass variations at medium to high concentrations. Moreover, our results showed that, even at high concentrations, zinc did not cause macroscopic test deformities due to anomalous arrangements of chambers.
Victoria L. Moore, Cassandra S. James, Brian Moss, Jane Fisher
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 203-216
https://doi.org/10.4467/16890027AP.13.0018.1115A survey of the summer phytoplankton communities of thirty-six moderately-deep north temperate lowland lakes showed that the proportions of Dinophyta and non-heterocyst-bearing cyanobacteria taxa, measured as biovolume, were inversely related to the total nitrogen: total phosphorus (TN:TP) ratio and that these groups were predominant in lakes where available nitrogen fell to undetectable concentrations. The proportion of heterocyst-bearing cyanobacteria was positively correlated to the TN:TP ratio and nitrate. Dinophyta and/or non-heterocystous cyanobacteria were prevalent in lakes with the highest epilimnion nutrient concentrations, whilst heterocystous cyanobacteria predominated in lakes with moderate nutrient concentrations. It is argued that the ability of Dinophyta to migrate vertically and to supplement their nutrient requirements though heterotrophy may enable them to be at least as successful as Cyanobacteria in high nutrient lakes and in overcoming nitrogen-scarcity. Our findings provide evidence that Dinophyta can be used as indicators of water quality.
Richard J. Payne
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 105-113
https://doi.org/10.4467/16890027AP.13.0011.1108To introduce the special issue this paper reviews the use of protists as bioindicators. Seven key advantages of protist bioindicators are highlighted, namely: environmental sensitivity, functional importance, distribution, size and numbers, response times, ease of analysis and preservation potential. Protist bioindicators have been used in a wide range of contexts from ecosystem restoration to fire history, and particularly environmental pollution. Most major protist groups have been used as bioindicators with diatoms, foraminifera and testate amoebae particularly widely studied. To increase uptake of protist bioindication techniques in routine environmental monitoring technique development should consider the needs of stakeholders from an early stage. Papers in this special issue reflect the diversity of both protist life and possible bioindicator applications.
Robert L. Barnett, W. Roland Gehrels, Dan J. Charman, Margot H. Saher, William A. Marshall
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 115-128
https://doi.org/10.4467/16890027AP.13.0012.1109Proxy based sea-level reconstructions are an important tool for defining past patterns of sea-level change and salt-marsh testate amoebae are a newly emerging proxy with high potential as sea-level indicators. This study develops existing analytical techniques concerned with the preparation and counting of testate amoebae for sea-level studies and demonstrates the predictive power of this group of micro-organisms. Two salt marshes in northwestern Norway were sampled for testate amoebae and multiple sub-samples were prepared using different procedures and count totals. Analytical efficiency can be improved upon by using a mild alkali, chemical disaggregant (5% KOH) to break up fibrous, salt-marsh peat and concentrate tests prior to counting. A count total of 100 individuals, rather than 150, can be used to make time gains with little or no loss of taxon information. The Norwegian salt-marsh testate amoebae showed strong zonation relative to tidal elevation. Key indicator taxa from the high marsh included Centropyxis cassis type, Cyclopyxis arcelloides type and Euglypha spp. Those from the low marsh included Difflugia pristis type and a distinctive morphotype of Centropyxis platystoma type. Combined, the two surface data sets from Norway were capable of predicting marsh surface elevations to within ± 0.09 m.
Julie Valentine, Stephen R. Davis, Jason R. Kirby, David M. Wilkinson
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 129-145
https://doi.org/10.4467/16890027AP.13.0013.1110The nature conservation, and wider environmental importance of peatlands, particularly in relation to carbon management, has led to there being a growing interest in attempting to manage degraded peatlands in a way that will restore them to fully functioning peatland ecosystems. Much of this management is concerned with the rewetting of these sites therefore it has become important to monitor the surface wetness of these bogs and if possible compare current wetness with previous, pre-damage, conditions. We present previously unpublished case studies of the use of testate amoebae to monitor bog restoration schemes in N.W. England (Holcroft Moss, Cheshire) and Ireland (Ardagullion Bog, Co. Longford). In addition we summarise the key conservation related conclusions of our previously published work on two other sites in N.W England – Astley Moss (in the Chat Moss complex of Greater Manchester) and Danes Moss (Cheshire). At Holcroft the record of lead pollution from the peat core allows us to date recent changes in the testate community preserved in a peat core and relate these to both conservation management and other changes in the landscape around the bog in over the last 50 years. Ardagullion Bog provides an illustration of the utility of using multiple peat cores in the testate monitoring of peat bog restoration and illustrates that a bog that has only suffered limited ‘damage’ is able to be restored to something close to pre damage conditions on a decadal time scale. We also summarise what we see as the main lessons from testate studies of bog restoration – both from the case studies described in this paper and from the wider literature - and discuss the conditions under which testate amoebae may be of particular use in peatland restoration.
Fabrizio Frontalini, Giulia Margaritelli, Fabio Francescangeli, Roberto Rettori, Eric Armynot Du Châtelet
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 147-160
https://doi.org/10.4467/16890027AP.13.0014.1111The benthic foraminiferal assemblages in Lake Varano (southern Italy) have been investigated in detail. Statistical analyses enable us to recognize two main biotopes and five sub-biotopes that reflect different ecological and environmental conditions. The assemblages mainly seem to be influenced by the hydrological (namely salinity) and sediment conditions in the lake. These biotopes are characterized by specific sub-assemblages and variations in relative species’ abundances. The Outer Lake Biotope is affected by marine influence and is dominated by the foraminiferal species Ammonia beccarii, Ammonia parkinsoniana and Aubignyna perlucida, which are more common in open water environments. In contrast, the Inner-Marginal Lake Biotope reflects more restricted conditions where low salinity values and sand are associated with high numbers of miliolids. These two main biotopes are thus subjected to different degrees of confinement and water residence times, both of which are related to the water exchange time of the lake with the Adriatic Sea. In addition five sub-biotopes (Intermediate Marine, Mixing, “Urban”, Marginal, and Innermost) represented by particular foraminiferal assemblages are identified that characterize particular sub-environments. These sub-biotopes are, to some extent, separated by salinity gradients as well as the grain-size and the organic matter of sediments.
Jennifer Garcia, Meryem Mojtahid, Hélène Howa, Elisabeth Michel, Ralf Schiebel, Céline Charbonnier, Pierre Anschutz, Franciscus J. Jorissen
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 161-180
https://doi.org/10.4467/16890027AP.13.0015.1112Benthic and planktic foraminiferal assemblages from two sediment cores (2000 m depth, 44°33′N-2°45′W) were analyzed to first compare modern and dead faunas and next to study changes in the hydrology of the southeastern Bay of Biscay (SE BoB) over the last 12.8 cal ka BP. Considering benthic ecosystem characteristics, the first part of the paleorecord (12.8–7.6 cal ka BP) is composed of laminated sediments that may have resulted from turbiditic overflow events, whereas occurrences of transported species (e.g. Nonionella sp., Cassidulina carinata) attest of continental influence at the core location. After 7.6 cal ka BP, the sediment becomes bioturbated concomitantly to the stabilization of the sea-level. The benthic foraminiferal fauna is largely dominated by Uvigerina peregrina suggesting a high seasonality with seasonal pulsed organic matter fluxes to the seafloor. On the other hand, the planktic foraminiferal composition indicates that surface water masses were under the influence of the polar front in the early record, which retreated at about 11.5 cal ka BP. The early Holocene is characterized by relatively warm and stratified water masses at 8.4–4.8 cal ka BP. The last 4.8 cal ka BP records a gradual sea surface water cooling trend and enhanced foraminiferal production from ~2.6 cal ka BP until present. The early (12.8–10.5 cal ka BP) and late (2.3–1.7 cal ka BP) Holocene are characterized by the presence of the planktic species Globigerinoides ruber probably caused by intrusions of the Iberian Poleward Current (IPC), and a negative state of the North Atlantic Oscillation (NAO).
Anna Sabbatini, Maria Pia Nardelli, Caterina Morigi, Alessandra Negri
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 181-192
https://doi.org/10.4467/16890027AP.13.0016.1113Monothalamous foraminifera with organic and agglutinated test walls (‘‘allogromiids’’ sensu lato) deserve attention because of their importance in deep-sea and shallow-water soft-bottom communities and their crucial phylogenetic position at the base of the foraminiferal evolutionary tree. However, our knowledge of the biodiversity and ecology of monothalamous foraminifera is very incomplete and geographically patchy. Here, we present a short review based on the available data on monothalamous, soft-walled foraminiferal taxa from the Adriatic Sea in response to several environmental parameters (i.e., organic matter, oxygen, grain size, depth). The main results of the studies provide evidence of the importance of these foraminiferal taxa in this shallow, temperate latitude area;they represent a start for the identification of soft-shelled monothalamous morphotypes that could be potential bioindicators of environments influenced by inputs of fresh waters, increasing eutrophication and consequent fluctuations in bottom-water oxygenation. The contribution of this soft-shelled component to living benthic foraminiferal assemblages appears not negligible and excluding it from foraminiferal studies can potentially lead to a loss of ecological information. The study, therefore, provide an atlas of the Adriatic soft-shelled foraminiferal taxa in order to 1) encourage the species-level description, if possible, or alternatively a basic morphotype characterization, 2) facilitate future comparisons of taxa from similar settings, 3) promote their potential use in future biomonitoring investigations together with the hard-shelled foraminifera.
Maria Pia Nardelli, Anna Sabbatini, Alessandra Negri
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 193-202
https://doi.org/10.4467/16890027AP.13.0017.1114Miliolid (calcareous imperforated test) foraminifera have large diffusion all over the world in a wide range of marine environments, but their distributional pattern in relation to heavy metal pollution is not clearly understood yet. The aim of this study was to better understand the biological response of the miliolid species Pseudotriloculina rotunda to experimental chronic exposure at several zinc concentrations. The duration of the experiment was 10 weeks, and six different concentrations of zinc were tested between 0 and 100 mg/L. Increasing zinc concentrations led to increasing delay or to complete cease of the new chambers’ construction, with consequences on growth rates and affected vitality and biomass variations at medium to high concentrations. Moreover, our results showed that, even at high concentrations, zinc did not cause macroscopic test deformities due to anomalous arrangements of chambers.
Victoria L. Moore, Cassandra S. James, Brian Moss, Jane Fisher
Acta Protozoologica, Volume 52, Issue 3, 2013, pp. 203-216
https://doi.org/10.4467/16890027AP.13.0018.1115A survey of the summer phytoplankton communities of thirty-six moderately-deep north temperate lowland lakes showed that the proportions of Dinophyta and non-heterocyst-bearing cyanobacteria taxa, measured as biovolume, were inversely related to the total nitrogen: total phosphorus (TN:TP) ratio and that these groups were predominant in lakes where available nitrogen fell to undetectable concentrations. The proportion of heterocyst-bearing cyanobacteria was positively correlated to the TN:TP ratio and nitrate. Dinophyta and/or non-heterocystous cyanobacteria were prevalent in lakes with the highest epilimnion nutrient concentrations, whilst heterocystous cyanobacteria predominated in lakes with moderate nutrient concentrations. It is argued that the ability of Dinophyta to migrate vertically and to supplement their nutrient requirements though heterotrophy may enable them to be at least as successful as Cyanobacteria in high nutrient lakes and in overcoming nitrogen-scarcity. Our findings provide evidence that Dinophyta can be used as indicators of water quality.
Publication date: 17.06.2013
Editor-in-Chief: Krzysztof Wiąckowski
O. Roger Anderson, Yonas I. Tekle
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 55-64
https://doi.org/10.4467/16890027AP.13.006.1085Cochliopodium megatetrastylus n. sp. is described based on light microscopy, fine structure and molecular genetic evidence. Amoebae are broadly oval to somewhat triangular during locomotion with average length of 37 μm and breadth of 50 μm, and surrounded by a hyaloplasm margin, somewhat narrow when at rest but more expanded during locomotion (~ 5–10 μm at the anterior). Sparsely occurring subpseudopodia, barely emergent from the hyaloplasm, are blunt and finger-like, occasionally becoming adhesive laterally or at the posterior. Cysts develop after 2–3 weeks in culture and are round with a distinct margin, decreasing in size from 20 to 5 μm during maturation. The granuloplasm contains refractile crystals. A vesicular nucleus (~ 6 μm), containing a nucleolus (2–3 μm), is variable in shape from somewhat lenticular in section to irregularly rounded with undulating or lobed margins. Surface scales (~ 0.3 μm in height) have an apical deeply concave funnel-like collar (~ 0.15 μm deep), without a spine, composed of radial fine rays and concentric filaments forming a finemesh, supported on four non-cross-linked styles (~ 0.2 μm apart) attached to a round to broadly angular base plate (0.6–1 μm) with a fine gridtexture. Cysts are rounded and enclosed by an organic wall bearing remnants of the scales on its outer surface. Both concatenated analysis of SSU-rDNA and COI genes and comparative morphologies support the designation of Cochliopodium megatetrastylus n. sp. as a new species.
Xumiao Chen, Liqiong Li, Xiaozhong Hu, Chen Shao, Saleh A. Al-Farraj, Khaled A. S. Al-Rasheid
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 65-72
https://doi.org/10.4467/16890027AP.13.007.1086The urostylid family Pseudokeronopsidae Borror and Wicklow, 1983 was considered to be a well-outlined taxon. Nevertheless, recent evidence, including morphological, ontogenetic, and molecular information, has consistently revealed the polyphyly of this family. In the present work, a new population of Thigmokeronopsis stoecki Shao et al., 2008 was found and its binary divisional process was described for the first time. In addition, the morphogenetic features of Thigmokeronopsis species and all the other pseudokeronopsids, for which detailed ontogenetic data are available, were rechecked and compared. This reveals that: (1) the ontogenetic process of T. stoecki corresponds well with its congeners T. jahodai and T. rubra except for the macronuclear behavior; (2) Apokeronopsis and Thigmokeronopsis share a similar ontogenetic mode despite of the differences in the number and origin of their buccal cirri; (3) most pseudokeronopsids share the same pattern in the origins of their oral primordia and fronto-ventral-transverse cirral anlagen, except for Pseudokeronopsis similis, which may not be a valid member of the family Pseudokeronopsidae.
Xumiao Chen, Yan Zhao, Saleh A. Al-Farraj, Saleh Al-Quraishy, Hamed A. El-Serehy, Chen Shao, Khaled A. S. Al-Rasheid
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 73-87
https://doi.org/10.4467/16890027AP.13.008.1087The morphology, morphogenesis and infraciliature of two marine euplotid ciliates, Euplotes dammamensis n. sp. and Euplotes balteatus (Dujardin, 1841) Kahl, 1932, isolated from a sandy beach of the Arabian Gulf, Saudi Arabia, were investigated using observations in vivo and protargol-impregnation methods. Euplotes dammamensis n. sp. is characterized by a combination of features including its huge body size (100–170 × 80–120 μm), 10 conspicuous dorsal ridges, 10 normal-sized frontoventral and two marginal cirri, and 11 dorsal kineties. Euplotes balteatus is mainly characterized by 10 frontoventral, two caudal, and two left marginal cirri, 7–10 dorsal kineties and 5–7 prominent dorsal ridges as well as double-eurystomus silverline system. The small subunit rRNA (SSU-rRNA) gene sequences were determined for both species and phylogenetic analyses based on these data indicated that E. dammamensis is most closely related to E. parabalteatus Jiang et al., 2010, and E. balteatus clusters with E. plicatum Valbonesi et al., 1997, E. orientalis Jiang et al., 2010, and E. bisulcatus Kahl, 1932.
Carlos Azevedo, Sérgio Carmona De São Clemente, Graça Casal, Patrícia Matos, Elsa Oliveira, Saleh Al-Quraishy, Edilson Rodrigues Matos
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 91-97
https://doi.org/10.4467/16890027AP.13.009.1088This study used light and electron microscopy to describe a myxosporean, polysporic, histozoic plasmodium infecting the gill filaments of the freshwater teleost, Semaprochilodus insignis, specimens of which were collected from the Trombetas River (Central Amazonian Region, Brazil). Ultrastructural analyses of the fish-infecting spores identified the parasite as Myxobolus insignis, an organism that occurs within whitish unequal-sized plasmodia located in the intralamellar epithelium of the gill. Based on the observed morphological and ultrastructural features of the plasmodia in this study three stages in the plasmodial evolution were distinguished, related to the sporogonic stages of Myxobolus insignis. The plasmodium walls were also found to constitute a number of layers of fibroblasts, surrounded by collagen fibres, which displayed different morphological arrangements according to the different phases of evolution. This represents the first time such ultrastructural features have been described in detail for Myxobolus insignis plasmodia and offers potentially significant points of comparison with plasmodia from other species of myxosporea.
Ján Jamriška, Alberto Rodríguez Barbón, David Modrý
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 99-103
https://doi.org/10.4467/16890027AP.13.0010.1089A new species of Isospora Schneider (Apicomplexa: Eimeriidae) is described from captive Blue-crowned Laughingthrush Dryonastes courtoisi (Ménégaux, 1923) (Passeriformes: Timaliidae). Sporulated oocysts of Isospora courtoisii n. sp. are ellipsoidal 24.5 × 14.5 μm. Micropyle and oocyst residuum are absent. Sporocysts are broadly ellipsoidal, 15.9 × 8.5 μm, with Stieda and substieda bodies. Sporocyst residuum is scattered composed of hundreds of small granules. Sporozoites are elongate and slightly curved, each with two refractile bodies. The nuclei of the sporozoites were not well discernible. Considering the critically endangered status of Dryonastes courtoisi and assumed high host specificity of described coccidium, also I. courtoisi can be classified as critically endangered organism.
O. Roger Anderson, Yonas I. Tekle
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 55-64
https://doi.org/10.4467/16890027AP.13.006.1085Cochliopodium megatetrastylus n. sp. is described based on light microscopy, fine structure and molecular genetic evidence. Amoebae are broadly oval to somewhat triangular during locomotion with average length of 37 μm and breadth of 50 μm, and surrounded by a hyaloplasm margin, somewhat narrow when at rest but more expanded during locomotion (~ 5–10 μm at the anterior). Sparsely occurring subpseudopodia, barely emergent from the hyaloplasm, are blunt and finger-like, occasionally becoming adhesive laterally or at the posterior. Cysts develop after 2–3 weeks in culture and are round with a distinct margin, decreasing in size from 20 to 5 μm during maturation. The granuloplasm contains refractile crystals. A vesicular nucleus (~ 6 μm), containing a nucleolus (2–3 μm), is variable in shape from somewhat lenticular in section to irregularly rounded with undulating or lobed margins. Surface scales (~ 0.3 μm in height) have an apical deeply concave funnel-like collar (~ 0.15 μm deep), without a spine, composed of radial fine rays and concentric filaments forming a finemesh, supported on four non-cross-linked styles (~ 0.2 μm apart) attached to a round to broadly angular base plate (0.6–1 μm) with a fine gridtexture. Cysts are rounded and enclosed by an organic wall bearing remnants of the scales on its outer surface. Both concatenated analysis of SSU-rDNA and COI genes and comparative morphologies support the designation of Cochliopodium megatetrastylus n. sp. as a new species.
Xumiao Chen, Liqiong Li, Xiaozhong Hu, Chen Shao, Saleh A. Al-Farraj, Khaled A. S. Al-Rasheid
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 65-72
https://doi.org/10.4467/16890027AP.13.007.1086The urostylid family Pseudokeronopsidae Borror and Wicklow, 1983 was considered to be a well-outlined taxon. Nevertheless, recent evidence, including morphological, ontogenetic, and molecular information, has consistently revealed the polyphyly of this family. In the present work, a new population of Thigmokeronopsis stoecki Shao et al., 2008 was found and its binary divisional process was described for the first time. In addition, the morphogenetic features of Thigmokeronopsis species and all the other pseudokeronopsids, for which detailed ontogenetic data are available, were rechecked and compared. This reveals that: (1) the ontogenetic process of T. stoecki corresponds well with its congeners T. jahodai and T. rubra except for the macronuclear behavior; (2) Apokeronopsis and Thigmokeronopsis share a similar ontogenetic mode despite of the differences in the number and origin of their buccal cirri; (3) most pseudokeronopsids share the same pattern in the origins of their oral primordia and fronto-ventral-transverse cirral anlagen, except for Pseudokeronopsis similis, which may not be a valid member of the family Pseudokeronopsidae.
Xumiao Chen, Yan Zhao, Saleh A. Al-Farraj, Saleh Al-Quraishy, Hamed A. El-Serehy, Chen Shao, Khaled A. S. Al-Rasheid
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 73-87
https://doi.org/10.4467/16890027AP.13.008.1087The morphology, morphogenesis and infraciliature of two marine euplotid ciliates, Euplotes dammamensis n. sp. and Euplotes balteatus (Dujardin, 1841) Kahl, 1932, isolated from a sandy beach of the Arabian Gulf, Saudi Arabia, were investigated using observations in vivo and protargol-impregnation methods. Euplotes dammamensis n. sp. is characterized by a combination of features including its huge body size (100–170 × 80–120 μm), 10 conspicuous dorsal ridges, 10 normal-sized frontoventral and two marginal cirri, and 11 dorsal kineties. Euplotes balteatus is mainly characterized by 10 frontoventral, two caudal, and two left marginal cirri, 7–10 dorsal kineties and 5–7 prominent dorsal ridges as well as double-eurystomus silverline system. The small subunit rRNA (SSU-rRNA) gene sequences were determined for both species and phylogenetic analyses based on these data indicated that E. dammamensis is most closely related to E. parabalteatus Jiang et al., 2010, and E. balteatus clusters with E. plicatum Valbonesi et al., 1997, E. orientalis Jiang et al., 2010, and E. bisulcatus Kahl, 1932.
Carlos Azevedo, Sérgio Carmona De São Clemente, Graça Casal, Patrícia Matos, Elsa Oliveira, Saleh Al-Quraishy, Edilson Rodrigues Matos
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 91-97
https://doi.org/10.4467/16890027AP.13.009.1088This study used light and electron microscopy to describe a myxosporean, polysporic, histozoic plasmodium infecting the gill filaments of the freshwater teleost, Semaprochilodus insignis, specimens of which were collected from the Trombetas River (Central Amazonian Region, Brazil). Ultrastructural analyses of the fish-infecting spores identified the parasite as Myxobolus insignis, an organism that occurs within whitish unequal-sized plasmodia located in the intralamellar epithelium of the gill. Based on the observed morphological and ultrastructural features of the plasmodia in this study three stages in the plasmodial evolution were distinguished, related to the sporogonic stages of Myxobolus insignis. The plasmodium walls were also found to constitute a number of layers of fibroblasts, surrounded by collagen fibres, which displayed different morphological arrangements according to the different phases of evolution. This represents the first time such ultrastructural features have been described in detail for Myxobolus insignis plasmodia and offers potentially significant points of comparison with plasmodia from other species of myxosporea.
Ján Jamriška, Alberto Rodríguez Barbón, David Modrý
Acta Protozoologica, Volume 52, Issue 2, 2013, pp. 99-103
https://doi.org/10.4467/16890027AP.13.0010.1089A new species of Isospora Schneider (Apicomplexa: Eimeriidae) is described from captive Blue-crowned Laughingthrush Dryonastes courtoisi (Ménégaux, 1923) (Passeriformes: Timaliidae). Sporulated oocysts of Isospora courtoisii n. sp. are ellipsoidal 24.5 × 14.5 μm. Micropyle and oocyst residuum are absent. Sporocysts are broadly ellipsoidal, 15.9 × 8.5 μm, with Stieda and substieda bodies. Sporocyst residuum is scattered composed of hundreds of small granules. Sporozoites are elongate and slightly curved, each with two refractile bodies. The nuclei of the sporozoites were not well discernible. Considering the critically endangered status of Dryonastes courtoisi and assumed high host specificity of described coccidium, also I. courtoisi can be classified as critically endangered organism.
Publication date: 21.04.2013
Editor-in-Chief: Krzysztof Wiąckowski
Celia Bulit, Miroslav Macek, David J. S. Montagnes
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 1-12
https://doi.org/10.4467/16890027AP.13.001.0829Planktonic ciliates occasionally form brief rapid increases in numbers (blooms) that can be trophically important. Although model simulations and mesocosm studies indicate that blooms occur over 10 to 20 days, field data are rarely suffi ciently detailed to reveal their occurrence and demise. Our data (collected over 57 weeks across a coastal lagoon) offer insights into the population dynamics of a single species, place these in the context of the entire ciliate assemblage, and provide guidance on what should continue to be examined. Specifically, to evaluate population dynamics we examine two species of Cyrtostrombidium, characterise temporal and spatial variation of their abundance, and relate these to abiotic phenomena and biological factors. This is also the first report of Cyrtostrombidium in a tropical coastal lagoon. Collectively our analysis reveals key aspects of the dynamics of this genus: 1) small-scale peaks in abundance are ~30 m in size and can persist for ~10–30 days, reaching a maximum of 100 cells ml–1; 2) these increases are driven by biotic factors (revealed through autocorrelation analysis); 3) long-term trends are driven by the shift between dry and rainy seasons and by the periods of isolation of lagoon from the sea (revealed through multiple regression analysis); 4) blooms may at times control primary production; 5) conjugation, an ecologically important event, may be associated with blooms (at times 9% of population was conjugating); and 6) dinoflagellate parasitism, poorly described in oligotrichs, is potentially important in population demise. These results both reflect on how ciliates may behave in short-term events and should encourage the continued need for detailed observations of field samples at a high taxonomic resolution.
Ekaterina Mironova, Irena Telesh, Sergei Skarlato
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 13-23
https://doi.org/10.4467/16890027AP.13.002.0830Ciliate communities in open waters of the meso-eutrophic Neva Estuary (the Baltic Sea) were studied in summer 2010. Abundance and biomass of ciliates were surprisingly low (0.03–1.9 ind ml–1 and 0.04–2.4 × 10–3 μg C ml–1), especially in samples with high detritus content. During this study we detected four ciliate species which are new for the Baltic Sea. Mixotrophic ciliates dominated at the majority of stations (28–67% of overall ciliate numbers). Their contribution was significantly higher in the outfall area and northern part of the Neva Estuary (Resort District), where total density of ciliates was low. Medium-sized ciliates (30–60 μm) were the most diverse and abundant (average contribution 59% of total abundance). The two parts of the estuary, separated from each other by a storm-surge barrier, differed slightly in their community structure (p < 0.05) but did not significantly differ in ciliate numbers and biomass values.
Hongbo Pan, Honggang Ma, Xiaozhong Hu, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 25-33
https://doi.org/10.4467/16890027AP.13.003.0831The present work investigates the living morphology and infraciliature of three marine cyrtophorid ciliates, which were isolated from Qingdao, China. Compared with its congeners, Orthotrochilia sinica spec. nov. can be distinguished by a combination of features: body slender and elliptical in outline, size about 50–60 × 20–25 μm in vivo, 18–21 somatic kineties, the length of the left perioral kinety treble the length of the right one, two ventrally located contractile vacuoles on the right side, and 25–32 nematodesmal rods. Based on current observations and the previous description, the diagnosis of Trochilioides tenuis (Deroux, 1976) Chen et al. 2011 is improved: cell size 30–40 × 20–35 μm in vivo, oval shaped in outline; consistently three right kineties, four left kineties and seven postoral kineties; a single contractile vacuole; marine habitat. A second species of Trochilioides, T. recta (Kahl, 1923) Chen et al. 2011 is re-described based on a Chinese population. Furthermore, a key to the identification of species of the genus Trochilioides whose infraciliature data are available is supplied, and Chlamydonyx trivialis (Fenchel, 1965) comb. nov. [basionym: Trochilioides trivialis Fenchel, 1965] is suggested.
Xuming Pan, Weiwei Liu, Zhenzhen Yi, Xinpeng Fan, Khaled A. S. Al-Rasheid, Xiaofeng Lin
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 35-49
https://doi.org/10.4467/16890027AP.13.004.0832Living observation and silver impregnation methods were used to investigate the morphology and infraciliature of three Frontonia ciliates (F. guangdongensis spec. nov., F. ocularis Bullington, 1939 and F. schaefferi Bullington, 1939) that were isolated from coastal waters of the South China Sea. Frontonia guangdongensis spec. nov. may be recognized by the combination of the following characteristics: cells about 160 × 35 μm in vivo; elongated body with right margin depressed in anterior third; length to width ratio 4:1 to 5:1; three or four vestibular and four or five postoral kineties; peniculi 1 and 2 each with four rows of kineties, peniculus 3 with two rows; one contractile vacuole in mid-body region right of cell median; brackish water habitat. A key based on morphological data for fourteen marine or brackish water Frontonia species found in China is also provided. In addition, the small subunit (SSU) rDNA gene was sequenced for F. ocularis Bullington, 1939. Our phylogenetic analyses support the contention that the genus Frontonia is not monophyletic.
Tatsuomi Matsuoka
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 51-54
https://doi.org/10.4467/16890027AP.13.005.0833n Colpoda cucullus, the signaling pathways for encystment induction involving protein phosphorylation have been believed to be triggered by an increase in the intracellular Ca2+ concentration promoted by cell-to-cell mechanical contact due to overpopulation. By means of fura 2 ratiometry, the present study showed that the intracellular Ca2+ concentration was actually elevated when vegetative cells were induced to encyst by being suspended at a high cell density in the presence of external free Ca2+ and suppressed by chelating external Ca2+. This result strongly suggests that an increase in the intracellular Ca2+ concentration caused by an inflow of Ca2+ promoted by cell-tocell mechanical contact due to overpopulation enhances the rate of encystation in Colpoda cucullus.
Celia Bulit, Miroslav Macek, David J. S. Montagnes
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 1-12
https://doi.org/10.4467/16890027AP.13.001.0829Planktonic ciliates occasionally form brief rapid increases in numbers (blooms) that can be trophically important. Although model simulations and mesocosm studies indicate that blooms occur over 10 to 20 days, field data are rarely suffi ciently detailed to reveal their occurrence and demise. Our data (collected over 57 weeks across a coastal lagoon) offer insights into the population dynamics of a single species, place these in the context of the entire ciliate assemblage, and provide guidance on what should continue to be examined. Specifically, to evaluate population dynamics we examine two species of Cyrtostrombidium, characterise temporal and spatial variation of their abundance, and relate these to abiotic phenomena and biological factors. This is also the first report of Cyrtostrombidium in a tropical coastal lagoon. Collectively our analysis reveals key aspects of the dynamics of this genus: 1) small-scale peaks in abundance are ~30 m in size and can persist for ~10–30 days, reaching a maximum of 100 cells ml–1; 2) these increases are driven by biotic factors (revealed through autocorrelation analysis); 3) long-term trends are driven by the shift between dry and rainy seasons and by the periods of isolation of lagoon from the sea (revealed through multiple regression analysis); 4) blooms may at times control primary production; 5) conjugation, an ecologically important event, may be associated with blooms (at times 9% of population was conjugating); and 6) dinoflagellate parasitism, poorly described in oligotrichs, is potentially important in population demise. These results both reflect on how ciliates may behave in short-term events and should encourage the continued need for detailed observations of field samples at a high taxonomic resolution.
Ekaterina Mironova, Irena Telesh, Sergei Skarlato
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 13-23
https://doi.org/10.4467/16890027AP.13.002.0830Ciliate communities in open waters of the meso-eutrophic Neva Estuary (the Baltic Sea) were studied in summer 2010. Abundance and biomass of ciliates were surprisingly low (0.03–1.9 ind ml–1 and 0.04–2.4 × 10–3 μg C ml–1), especially in samples with high detritus content. During this study we detected four ciliate species which are new for the Baltic Sea. Mixotrophic ciliates dominated at the majority of stations (28–67% of overall ciliate numbers). Their contribution was significantly higher in the outfall area and northern part of the Neva Estuary (Resort District), where total density of ciliates was low. Medium-sized ciliates (30–60 μm) were the most diverse and abundant (average contribution 59% of total abundance). The two parts of the estuary, separated from each other by a storm-surge barrier, differed slightly in their community structure (p < 0.05) but did not significantly differ in ciliate numbers and biomass values.
Hongbo Pan, Honggang Ma, Xiaozhong Hu, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 25-33
https://doi.org/10.4467/16890027AP.13.003.0831The present work investigates the living morphology and infraciliature of three marine cyrtophorid ciliates, which were isolated from Qingdao, China. Compared with its congeners, Orthotrochilia sinica spec. nov. can be distinguished by a combination of features: body slender and elliptical in outline, size about 50–60 × 20–25 μm in vivo, 18–21 somatic kineties, the length of the left perioral kinety treble the length of the right one, two ventrally located contractile vacuoles on the right side, and 25–32 nematodesmal rods. Based on current observations and the previous description, the diagnosis of Trochilioides tenuis (Deroux, 1976) Chen et al. 2011 is improved: cell size 30–40 × 20–35 μm in vivo, oval shaped in outline; consistently three right kineties, four left kineties and seven postoral kineties; a single contractile vacuole; marine habitat. A second species of Trochilioides, T. recta (Kahl, 1923) Chen et al. 2011 is re-described based on a Chinese population. Furthermore, a key to the identification of species of the genus Trochilioides whose infraciliature data are available is supplied, and Chlamydonyx trivialis (Fenchel, 1965) comb. nov. [basionym: Trochilioides trivialis Fenchel, 1965] is suggested.
Xuming Pan, Weiwei Liu, Zhenzhen Yi, Xinpeng Fan, Khaled A. S. Al-Rasheid, Xiaofeng Lin
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 35-49
https://doi.org/10.4467/16890027AP.13.004.0832Living observation and silver impregnation methods were used to investigate the morphology and infraciliature of three Frontonia ciliates (F. guangdongensis spec. nov., F. ocularis Bullington, 1939 and F. schaefferi Bullington, 1939) that were isolated from coastal waters of the South China Sea. Frontonia guangdongensis spec. nov. may be recognized by the combination of the following characteristics: cells about 160 × 35 μm in vivo; elongated body with right margin depressed in anterior third; length to width ratio 4:1 to 5:1; three or four vestibular and four or five postoral kineties; peniculi 1 and 2 each with four rows of kineties, peniculus 3 with two rows; one contractile vacuole in mid-body region right of cell median; brackish water habitat. A key based on morphological data for fourteen marine or brackish water Frontonia species found in China is also provided. In addition, the small subunit (SSU) rDNA gene was sequenced for F. ocularis Bullington, 1939. Our phylogenetic analyses support the contention that the genus Frontonia is not monophyletic.
Tatsuomi Matsuoka
Acta Protozoologica, Volume 52, Issue 1, 2013, pp. 51-54
https://doi.org/10.4467/16890027AP.13.005.0833n Colpoda cucullus, the signaling pathways for encystment induction involving protein phosphorylation have been believed to be triggered by an increase in the intracellular Ca2+ concentration promoted by cell-to-cell mechanical contact due to overpopulation. By means of fura 2 ratiometry, the present study showed that the intracellular Ca2+ concentration was actually elevated when vegetative cells were induced to encyst by being suspended at a high cell density in the presence of external free Ca2+ and suppressed by chelating external Ca2+. This result strongly suggests that an increase in the intracellular Ca2+ concentration caused by an inflow of Ca2+ promoted by cell-tocell mechanical contact due to overpopulation enhances the rate of encystation in Colpoda cucullus.
Publication date: 13.01.2013
Editor-in-Chief: Krzysztof Wiąckowski
O. Roger Anderson, Thomas Cavalier-Smith
Acta Protozoologica, Volume 51, Issue 4, 2012, pp. 291-304
https://doi.org/10.4467/16890027AP.12.023.0783We describe Diplophrys parva n. sp., a freshwater heterotroph, using fine structural and sequence evidence. Cells are small (L = 6.5 ± 0.08, W = 5.5 ± 0.06 µm; mean ± SE) enclosed by an envelope/theca of overlapping scales, slightly oval to elongated-oval with rounded ends, (1.0 × 0.5–0.7 µm), one to several intracellular refractive granules (~ 1.0–2.0 µm), smaller hyaline peripheral vacuoles, a nucleus with central nucleolus, tubulo-cristate mitochondria, and a prominent Golgi apparatus with multiple stacked saccules (~ 10). It is smaller than published sizes of Diplophrys archeri (~ 10–20 µm), modestly less than Diplophrys marina (~ 5–9 µm), and differs in scale size and morphology from D. marina. No cysts were observed. We transfer D. marina to a new genus Amphifila as it falls within a mo-lecular phylogenetic clade extremely distant from that including D. parva. Based on morphological and molecular phylogenetic evidence, Labyrinthulea are revised to include six new families, including Diplophryidae for Diplophrys and Amphifilidae containing Amphifila. The other new families have distinctive morphology: Oblongichytriidae and Aplanochytriidae are distinct clades on the rDNA tree, but Sorodiplophryidae and Althorniidae lack sequence data. Aplanochytriidae is in Labyrinthulida; the rest are in Thraustochytrida; Laby-rinthomyxa is excluded.
Daniel J. G. Lahr, Gabriela M. Kubik, Jessica Grant, O. Roger Anderson, Laura A. Katz
Acta Protozoologica, Volume 51, Issue 4, 2012, pp. 305-318
https://doi.org/10.4467/16890027AP.12.024.0784We describe the amoeboid isolate ATCC© 50593™ as a new taxon, Telaepolella tubasferens n. gen. n. sp. This multinucleated amoeba has filose pseudopods and is superficially similar to members of the vampyrellids (Rhizaria) such as Arachnula impatiens Cienkowski, 1876, which was the original identification upon deposition. However, previous multigene analyses place this taxon within the Gracilipodida Lahr & Katz 2011 in the Amoebozoa. Here, we document the morphology of this organism at multiple life history stages and describe data underlying the description as a new taxon. We demonstrate that T. tubaspherens is distinct from Arachnula and other rhizarians (Theratromyxa, Leptophrys) in a suite of morphological characters such as general body shape, relative size of pseudopods, distinction of ecto- and endoplasmic regions, and visibility of nuclei in non-stained cells (an important diagnostic character). Although Amoebozoa taxa generally have lobose pseudopods, genera in Gracilipodida such as Flamella and Filamoeba as well as several organisms previously classified as protosteloid amoebae (e.g. schizoplasmodiis, cavosteliids and Stemonitales) present filose pseudopodia. Thus, classification of amoeboid organisms merely by filose-lobose distinction must be reconsidered.
Yan Zhao, Feng Gao, Jiqiu Li, Zhenzhen Yi
Acta Protozoologica, Volume 51, Issue 4, 2012, pp. 319-328
https://doi.org/10.4467/16890027AP.12.025.0785In order to better understand phylogenetic relationships among tintinnid ciliated protozoa, we sequenced and analyzed the SSU rDNA and ITS1-5.8S-ITS2 regions of 10 species belonging to five genera in the order Tintinnida. The secondary structures of the ITS2 region were compared among 8 closely related genera, revealing two stable helices of the palm. In addition, we identified a bulge absence in position II of the ITS2 putative secondary structures of species in basal positions in phylogenetic trees, suggesting the absence bulge might be an ancestral character in the order Tintinnida. Phylogenetic analyses based on SSU rDNA and ITS1-5.8S-ITS2 regions sequence show 1) divergences within the family Tintinnidae are higher than that among other four families (Codonellidae, Ptychocylididae, Metacylididae and Codonellopsidae), suggesting the subdivision of the this family; 2) the family Ptychocylididae is polyphyletic; 3) the subdivision of Tintinnopsis are suggested, because the Tintinnopsis spp. scatter into different clades; 4) species with agglutinated loricae are not clearly separated from that with hyaline ones.
Ján Jamriška, David Modrý
Acta Protozoologica, Volume 51, Issue 4, 2012, pp. 329-333
https://doi.org/10.4467/16890027AP.12.026.0786New species of eimeriid coccidia (Apicomplexa: Eimeriidae) is described from the Common Wood Pigeon Columba palumbus (Aves: Columbidae). Sporulated oocysts of Eimeria columbapalumbi sp. n. are ellipsoidal 24–17 × 18–15 µm. Micropyle and oocyst residuum are absent. Sporocysts are broadly ellipsoidal, 11–16 × 6–7µm, with Stieda body. Substiedal body is absent. Sporocyst residuum is scattered, composed of hundreds of small granules. Sporozoites are elongate and slightly curved, each with two refractile bodies. There are two irregularly shaped polar granules present in the oocyst. The endogenous development takes place within the enterocytes of jejunum.
O. Roger Anderson, Thomas Cavalier-Smith
Acta Protozoologica, Volume 51, Issue 4, 2012, pp. 291-304
https://doi.org/10.4467/16890027AP.12.023.0783We describe Diplophrys parva n. sp., a freshwater heterotroph, using fine structural and sequence evidence. Cells are small (L = 6.5 ± 0.08, W = 5.5 ± 0.06 µm; mean ± SE) enclosed by an envelope/theca of overlapping scales, slightly oval to elongated-oval with rounded ends, (1.0 × 0.5–0.7 µm), one to several intracellular refractive granules (~ 1.0–2.0 µm), smaller hyaline peripheral vacuoles, a nucleus with central nucleolus, tubulo-cristate mitochondria, and a prominent Golgi apparatus with multiple stacked saccules (~ 10). It is smaller than published sizes of Diplophrys archeri (~ 10–20 µm), modestly less than Diplophrys marina (~ 5–9 µm), and differs in scale size and morphology from D. marina. No cysts were observed. We transfer D. marina to a new genus Amphifila as it falls within a mo-lecular phylogenetic clade extremely distant from that including D. parva. Based on morphological and molecular phylogenetic evidence, Labyrinthulea are revised to include six new families, including Diplophryidae for Diplophrys and Amphifilidae containing Amphifila. The other new families have distinctive morphology: Oblongichytriidae and Aplanochytriidae are distinct clades on the rDNA tree, but Sorodiplophryidae and Althorniidae lack sequence data. Aplanochytriidae is in Labyrinthulida; the rest are in Thraustochytrida; Laby-rinthomyxa is excluded.
Daniel J. G. Lahr, Gabriela M. Kubik, Jessica Grant, O. Roger Anderson, Laura A. Katz
Acta Protozoologica, Volume 51, Issue 4, 2012, pp. 305-318
https://doi.org/10.4467/16890027AP.12.024.0784We describe the amoeboid isolate ATCC© 50593™ as a new taxon, Telaepolella tubasferens n. gen. n. sp. This multinucleated amoeba has filose pseudopods and is superficially similar to members of the vampyrellids (Rhizaria) such as Arachnula impatiens Cienkowski, 1876, which was the original identification upon deposition. However, previous multigene analyses place this taxon within the Gracilipodida Lahr & Katz 2011 in the Amoebozoa. Here, we document the morphology of this organism at multiple life history stages and describe data underlying the description as a new taxon. We demonstrate that T. tubaspherens is distinct from Arachnula and other rhizarians (Theratromyxa, Leptophrys) in a suite of morphological characters such as general body shape, relative size of pseudopods, distinction of ecto- and endoplasmic regions, and visibility of nuclei in non-stained cells (an important diagnostic character). Although Amoebozoa taxa generally have lobose pseudopods, genera in Gracilipodida such as Flamella and Filamoeba as well as several organisms previously classified as protosteloid amoebae (e.g. schizoplasmodiis, cavosteliids and Stemonitales) present filose pseudopodia. Thus, classification of amoeboid organisms merely by filose-lobose distinction must be reconsidered.
Yan Zhao, Feng Gao, Jiqiu Li, Zhenzhen Yi
Acta Protozoologica, Volume 51, Issue 4, 2012, pp. 319-328
https://doi.org/10.4467/16890027AP.12.025.0785In order to better understand phylogenetic relationships among tintinnid ciliated protozoa, we sequenced and analyzed the SSU rDNA and ITS1-5.8S-ITS2 regions of 10 species belonging to five genera in the order Tintinnida. The secondary structures of the ITS2 region were compared among 8 closely related genera, revealing two stable helices of the palm. In addition, we identified a bulge absence in position II of the ITS2 putative secondary structures of species in basal positions in phylogenetic trees, suggesting the absence bulge might be an ancestral character in the order Tintinnida. Phylogenetic analyses based on SSU rDNA and ITS1-5.8S-ITS2 regions sequence show 1) divergences within the family Tintinnidae are higher than that among other four families (Codonellidae, Ptychocylididae, Metacylididae and Codonellopsidae), suggesting the subdivision of the this family; 2) the family Ptychocylididae is polyphyletic; 3) the subdivision of Tintinnopsis are suggested, because the Tintinnopsis spp. scatter into different clades; 4) species with agglutinated loricae are not clearly separated from that with hyaline ones.
Ján Jamriška, David Modrý
Acta Protozoologica, Volume 51, Issue 4, 2012, pp. 329-333
https://doi.org/10.4467/16890027AP.12.026.0786New species of eimeriid coccidia (Apicomplexa: Eimeriidae) is described from the Common Wood Pigeon Columba palumbus (Aves: Columbidae). Sporulated oocysts of Eimeria columbapalumbi sp. n. are ellipsoidal 24–17 × 18–15 µm. Micropyle and oocyst residuum are absent. Sporocysts are broadly ellipsoidal, 11–16 × 6–7µm, with Stieda body. Substiedal body is absent. Sporocyst residuum is scattered, composed of hundreds of small granules. Sporozoites are elongate and slightly curved, each with two refractile bodies. There are two irregularly shaped polar granules present in the oocyst. The endogenous development takes place within the enterocytes of jejunum.
Publication date: 19.12.2012
Editor-in-Chief: Krzysztof Wiąckowski
David M. Wilkinson , Angela L. Creevy, Julie Valentine
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 189-199
https://doi.org/10.4467/16890027AP.12.015.0761This essay introduces the special issue of this journal on the ecology of soil protists. This issue marks approximately the first 100 years of soil protistology as a discipline as some of the first studies to show that protozoa were an important part of soil ecology took place at Rothamsted, in southern England, towards the end of the first decade of the twentieth century. Much of the work on soil protists – and indeed the papers in this special issue – concentrate on traditional protozoa. In addition it is now realised that slime molds (Eumycetozoans) can potentially make an important contribution to the numbers and diversity of soil amoebae. We also argue that diatoms and other algae are likely important in soils and in need of more detailed study. By its nature microbiology (including soil protist ecology) is a science limited by technology – for example the subject could not really exist before the invention of the microscope. We suggest ways in which newer technologies (molecular methods, stable isotopes etc) may contribute to future studies on the ecology of soil protists.
Steven L. Stephenson, Alan Feest
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 201-208
https://doi.org/10.4467/16890027AP.12.016.0762Eumycetozoans, commonly referred to as slime moulds, are common to abundant organisms in soils. Three groups of slime moulds (myxogastrids, dictyostelids and protostelids) are recognized, and the first two of these are among the most important bacterivores in the soil microhabitat. The purpose of this paper is first to provide a brief description of all three groups and then to review what is known about their distribution and ecology in soils.
O. Roger Anderson
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 209-221
https://doi.org/10.4467/16890027AP.12.017.0763Current research is reviewed on aquatic and soil microbial ecology with attention to the fate of organic carbon in bacterial-based protist food webs, including some new data. Particular attention is given to the effects of pulsed sources of low-molecular weight organic sources of carbon on soil respiration, changes in bacterial, nanoflagellate, and naked amoeba C-biomass, and evidence for throughput of carbon in microbial food webs in Arctic and some low-latitude, temperate soil environments. The proportion of pulsed sources of glucose-C that is sequestered in microbial biomass relative to loss as CO2 is examined in laboratory experimental studies, and implications of the research for microbial community dynamics and global warming due to terrestrial sources of respiratory CO2 are discussed.
Regin Rønn, Mette Vestergård, Flemming Ekelund
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 223-235
https://doi.org/10.4467/16890027AP.12.018.0764Bacteria, protozoa and nematodes interact closely in soil ecosystems. Protozoa and nematodes eat bacteria (and occasionally each other), while bacteria defend themselves using chemical substances, resistant cell walls, irregular shapes and motility. Protozoa and nematodes are very different types of organisms, and hence apply very different feeding mechanisms; thus many protozoa can pick and choose individual bacterial cells, whereas nematodes ingest bacterial patches more uncritically. Protozoa and nematode are both aquatic organisms whose activity depends on available soil water, but differences in size, motility, resting stages and reproductive strategies mean that the soil physico-chemical environment influences the activity of protozoa and nematodes differently. For example, the relative importance of protozoa compared to nematodes may shift towards protozoa in very clay-rich soils. The interactions between the three organism groups have major ecological consequences such as modification of the bacterial communities and increased nitrogen mineralisation, both of which affect plant growth. Increased nitrogen mineralisation will usually be beneficial for plant growth, whereas the grazing induced changes in the bacterial communities can be both beneficial and detrimental to plants. Selective protozoan grazing can favour plant inhibiting bacteria. This may be a problem in clay rich soils where protozoa have better life conditions than nematodes.
Michael Bonkowski, Marianne Clarholm
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 237-247
https://doi.org/10.4467/16890027AP.12.019.0765By feeding on bacterial biomass protozoa play an acknowledged role in the liberation of nutrients in the plant rhizosphere. In addition there are suggestions that plants have mechanisms working through changes in root architecture and initiation of active release from soil organic matter, which are used to improve uptake and recirculation of nutrients in the ecosystem. All processes are carried out on a local scale in soil with roots, bacteria and protozoa interacting. The many actors and the small scale of interactions make experimentation difficult. We discuss mistakes, pit falls and misinterpretations and provide suggestions for improvement. Recent methodological progress has opened new exciting avenues for protozoan research. New techniques have already helped to reveal protozoan regulation of cooperation as well as conflict in bacterial communities. These mechanisms in turn affect bacterial functioning and target molecular control points in rhizosphere food webs in relation to plants. Integrating nutritional and regulatory aspects into new concepts of protozoan functioning in soil is a challenging frontier in protozoology.
Anne Winding, Jana Oberender
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 249-258
https://doi.org/10.4467/16890027AP.12.020.0766Bacteria producing secondary metabolites with antagonistic effects on fungal pathogens have received attention during the last decades as an alternative to chemical pesticides. They, however, might also have effects on indigenous soil organisms like bacteria and protozoa, the latter ones being among the most important grazers of bacteria in soil. The present study reports on the effect of the potential biocontrol agent Pseudomonas fluorescens CHA0 and its genetically modified derivative CHA0/pME3424 on indigenous soil bacteria and protozoa in a soil system. CHA0/pME3424 overproduces two of the secondary metabolites produced by CHA0: the polyketide antibiotics pyoluteorin (Plt) and 2,4-diacetylphloroglucinol (DAPG). P. fluorescens CHA0/gfp1 and CHA0/pME3424 both negatively affected the abundance of soil bacteria and protozoa and the genetic community structure of Kinetoplastida studied by PCR-DGGE. The negative effects were detectable after 14 days but were decreasing and are expected to be temporary. The overproducer of secondary metabolites did not differ in effect from the wild type. The soil respiration and bacterial genetic community structure were not significantly affected. The study shows the soil bacteria and protozoa to be temporary affected by bacteria producing secondary metabolites, which can have implications for nutrient-cycling in soil and environmental risks of biocontrol agents.
Martin Vohník, Zuzana Burdíková, David M. Wilkinson
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 259-269
https://doi.org/10.4467/16890027AP.12.021.0767Testate amoebae (TA) are an important part of soil microbial communities and in certain ecosystems they may represent a substantial proportion of total microbial biomass. Their distribution and abundance is driven by various abiotic factors (e.g. pH, organic matter, soil moisture, soil/water chemistry) but comparatively less is known about the role of biotic interactions. TA often co-occur with Ericaceae, a ubiquitous plant family inhabiting acidic soils with poor nutrient status. Ericaceae can significantly change soil properties through production of recalcitrant litter and possibly also due to root exudates and activities of root-inhabiting fungi; this may result in profound modifications of microbial communities. A recent study from northwest England shows that the invasive ericaceous shrub Rhododendron ponticum may significantly modify communities of soil TA. Here, we investigate the effect of pH, organic matter, soil moisture and R. ponticum presence on TA communities within the native range of the ericaceous shrub at two sites in south Spain and compare our results with the previous study from NW England. At the Spanish sites, organic matter content, R. ponticum presence and pH affected occurrence and abundance of several TA species; R. ponticum presence and organic matter content were highly correlated and explained most of the observed variability in TA communities (= the effect of the R. ponticum rhizosphere). R. ponticum rhizosphere affected especially TA with relatively large tests, i.e. Cyclopyxis eurystoma, Phryganella acropodia and Trigonopyxis arcula. Interestingly, T. arcula was also positively associated with R. ponticum in the previously studied British sites. The rhizosphere of the ericaceous shrub appears to have a positive effect on testate amoebae taxon richness at the two studied autochthonous Spanish sites but may reduce taxon richness in the sites in Britain where R. ponticum is an introduced species. Such possible positive/negative effects of native/invasive species, as well as other plant guilds, on TA communities clearly deserve further investigation.
Marijke Ooms, Louis Beyens, Stijn Temmerman
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 271-289
https://doi.org/10.4467/16890027AP.12.022.0768Few studies have examined testate amoebae assemblages of estuarine tidal marshes. This study investigates the possibility of using soil testate amoebae assemblages of a brackish tidal marsh (Scheldt estuary, Belgium) as a proxy for water level changes. On the marsh surface an elevation gradient is sampled to be analyzed for testate amoebae assemblages and sediment characteristics. Further, vegetation, flooding frequency and soil conductivity have been taken into account to explain the testate amoebae species variation. The data reveal that testate amoebae are not able to establish assemblages at the brackish tidal marsh part with flooding frequencies equal to or higher than 36.5%. Further, two separate testate amoebae zones are distinguished based on cluster analysis. The lower zone’s testate amoebae species composition is influenced by the flooding frequency (~ elevation) and particle size, while the species variability in the higher zone is related to the organic content of the soil and particle size. These observations suggest that the ecological meaning of elevation shifts over its range on the brackish tidal marsh Testate amoeba assemblages in such a brackish habitat show thus a vertical zonation (RMSEP: 0.19 m) that is comparable to the vertical zonation of testate amoebae and other protists on freshwater tidal marshes and salt marshes.
David M. Wilkinson , Angela L. Creevy, Julie Valentine
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 189-199
https://doi.org/10.4467/16890027AP.12.015.0761This essay introduces the special issue of this journal on the ecology of soil protists. This issue marks approximately the first 100 years of soil protistology as a discipline as some of the first studies to show that protozoa were an important part of soil ecology took place at Rothamsted, in southern England, towards the end of the first decade of the twentieth century. Much of the work on soil protists – and indeed the papers in this special issue – concentrate on traditional protozoa. In addition it is now realised that slime molds (Eumycetozoans) can potentially make an important contribution to the numbers and diversity of soil amoebae. We also argue that diatoms and other algae are likely important in soils and in need of more detailed study. By its nature microbiology (including soil protist ecology) is a science limited by technology – for example the subject could not really exist before the invention of the microscope. We suggest ways in which newer technologies (molecular methods, stable isotopes etc) may contribute to future studies on the ecology of soil protists.
Steven L. Stephenson, Alan Feest
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 201-208
https://doi.org/10.4467/16890027AP.12.016.0762Eumycetozoans, commonly referred to as slime moulds, are common to abundant organisms in soils. Three groups of slime moulds (myxogastrids, dictyostelids and protostelids) are recognized, and the first two of these are among the most important bacterivores in the soil microhabitat. The purpose of this paper is first to provide a brief description of all three groups and then to review what is known about their distribution and ecology in soils.
O. Roger Anderson
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 209-221
https://doi.org/10.4467/16890027AP.12.017.0763Current research is reviewed on aquatic and soil microbial ecology with attention to the fate of organic carbon in bacterial-based protist food webs, including some new data. Particular attention is given to the effects of pulsed sources of low-molecular weight organic sources of carbon on soil respiration, changes in bacterial, nanoflagellate, and naked amoeba C-biomass, and evidence for throughput of carbon in microbial food webs in Arctic and some low-latitude, temperate soil environments. The proportion of pulsed sources of glucose-C that is sequestered in microbial biomass relative to loss as CO2 is examined in laboratory experimental studies, and implications of the research for microbial community dynamics and global warming due to terrestrial sources of respiratory CO2 are discussed.
Regin Rønn, Mette Vestergård, Flemming Ekelund
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 223-235
https://doi.org/10.4467/16890027AP.12.018.0764Bacteria, protozoa and nematodes interact closely in soil ecosystems. Protozoa and nematodes eat bacteria (and occasionally each other), while bacteria defend themselves using chemical substances, resistant cell walls, irregular shapes and motility. Protozoa and nematodes are very different types of organisms, and hence apply very different feeding mechanisms; thus many protozoa can pick and choose individual bacterial cells, whereas nematodes ingest bacterial patches more uncritically. Protozoa and nematode are both aquatic organisms whose activity depends on available soil water, but differences in size, motility, resting stages and reproductive strategies mean that the soil physico-chemical environment influences the activity of protozoa and nematodes differently. For example, the relative importance of protozoa compared to nematodes may shift towards protozoa in very clay-rich soils. The interactions between the three organism groups have major ecological consequences such as modification of the bacterial communities and increased nitrogen mineralisation, both of which affect plant growth. Increased nitrogen mineralisation will usually be beneficial for plant growth, whereas the grazing induced changes in the bacterial communities can be both beneficial and detrimental to plants. Selective protozoan grazing can favour plant inhibiting bacteria. This may be a problem in clay rich soils where protozoa have better life conditions than nematodes.
Michael Bonkowski, Marianne Clarholm
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 237-247
https://doi.org/10.4467/16890027AP.12.019.0765By feeding on bacterial biomass protozoa play an acknowledged role in the liberation of nutrients in the plant rhizosphere. In addition there are suggestions that plants have mechanisms working through changes in root architecture and initiation of active release from soil organic matter, which are used to improve uptake and recirculation of nutrients in the ecosystem. All processes are carried out on a local scale in soil with roots, bacteria and protozoa interacting. The many actors and the small scale of interactions make experimentation difficult. We discuss mistakes, pit falls and misinterpretations and provide suggestions for improvement. Recent methodological progress has opened new exciting avenues for protozoan research. New techniques have already helped to reveal protozoan regulation of cooperation as well as conflict in bacterial communities. These mechanisms in turn affect bacterial functioning and target molecular control points in rhizosphere food webs in relation to plants. Integrating nutritional and regulatory aspects into new concepts of protozoan functioning in soil is a challenging frontier in protozoology.
Anne Winding, Jana Oberender
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 249-258
https://doi.org/10.4467/16890027AP.12.020.0766Bacteria producing secondary metabolites with antagonistic effects on fungal pathogens have received attention during the last decades as an alternative to chemical pesticides. They, however, might also have effects on indigenous soil organisms like bacteria and protozoa, the latter ones being among the most important grazers of bacteria in soil. The present study reports on the effect of the potential biocontrol agent Pseudomonas fluorescens CHA0 and its genetically modified derivative CHA0/pME3424 on indigenous soil bacteria and protozoa in a soil system. CHA0/pME3424 overproduces two of the secondary metabolites produced by CHA0: the polyketide antibiotics pyoluteorin (Plt) and 2,4-diacetylphloroglucinol (DAPG). P. fluorescens CHA0/gfp1 and CHA0/pME3424 both negatively affected the abundance of soil bacteria and protozoa and the genetic community structure of Kinetoplastida studied by PCR-DGGE. The negative effects were detectable after 14 days but were decreasing and are expected to be temporary. The overproducer of secondary metabolites did not differ in effect from the wild type. The soil respiration and bacterial genetic community structure were not significantly affected. The study shows the soil bacteria and protozoa to be temporary affected by bacteria producing secondary metabolites, which can have implications for nutrient-cycling in soil and environmental risks of biocontrol agents.
Martin Vohník, Zuzana Burdíková, David M. Wilkinson
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 259-269
https://doi.org/10.4467/16890027AP.12.021.0767Testate amoebae (TA) are an important part of soil microbial communities and in certain ecosystems they may represent a substantial proportion of total microbial biomass. Their distribution and abundance is driven by various abiotic factors (e.g. pH, organic matter, soil moisture, soil/water chemistry) but comparatively less is known about the role of biotic interactions. TA often co-occur with Ericaceae, a ubiquitous plant family inhabiting acidic soils with poor nutrient status. Ericaceae can significantly change soil properties through production of recalcitrant litter and possibly also due to root exudates and activities of root-inhabiting fungi; this may result in profound modifications of microbial communities. A recent study from northwest England shows that the invasive ericaceous shrub Rhododendron ponticum may significantly modify communities of soil TA. Here, we investigate the effect of pH, organic matter, soil moisture and R. ponticum presence on TA communities within the native range of the ericaceous shrub at two sites in south Spain and compare our results with the previous study from NW England. At the Spanish sites, organic matter content, R. ponticum presence and pH affected occurrence and abundance of several TA species; R. ponticum presence and organic matter content were highly correlated and explained most of the observed variability in TA communities (= the effect of the R. ponticum rhizosphere). R. ponticum rhizosphere affected especially TA with relatively large tests, i.e. Cyclopyxis eurystoma, Phryganella acropodia and Trigonopyxis arcula. Interestingly, T. arcula was also positively associated with R. ponticum in the previously studied British sites. The rhizosphere of the ericaceous shrub appears to have a positive effect on testate amoebae taxon richness at the two studied autochthonous Spanish sites but may reduce taxon richness in the sites in Britain where R. ponticum is an introduced species. Such possible positive/negative effects of native/invasive species, as well as other plant guilds, on TA communities clearly deserve further investigation.
Marijke Ooms, Louis Beyens, Stijn Temmerman
Acta Protozoologica, Volume 51, Issue 3, 2012, pp. 271-289
https://doi.org/10.4467/16890027AP.12.022.0768Few studies have examined testate amoebae assemblages of estuarine tidal marshes. This study investigates the possibility of using soil testate amoebae assemblages of a brackish tidal marsh (Scheldt estuary, Belgium) as a proxy for water level changes. On the marsh surface an elevation gradient is sampled to be analyzed for testate amoebae assemblages and sediment characteristics. Further, vegetation, flooding frequency and soil conductivity have been taken into account to explain the testate amoebae species variation. The data reveal that testate amoebae are not able to establish assemblages at the brackish tidal marsh part with flooding frequencies equal to or higher than 36.5%. Further, two separate testate amoebae zones are distinguished based on cluster analysis. The lower zone’s testate amoebae species composition is influenced by the flooding frequency (~ elevation) and particle size, while the species variability in the higher zone is related to the organic content of the soil and particle size. These observations suggest that the ecological meaning of elevation shifts over its range on the brackish tidal marsh Testate amoeba assemblages in such a brackish habitat show thus a vertical zonation (RMSEP: 0.19 m) that is comparable to the vertical zonation of testate amoebae and other protists on freshwater tidal marshes and salt marshes.
Publication date: 27.09.2012
Editor-in-Chief: Krzysztof Wiąckowski
Janina Kaczanowska, Mauryla Kiersnowska, Hanna Fabczak, Szymon Kaczanowski, Andrzej Kaczanowski
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 91-111
https://doi.org/10.4467/16890027AP.12.008.0512During cell cycle of a ciliate Tetrahymena thermophila the divisions of micro- and macronucleus, cortical morphogenesis and cytokinesis are temporarily coordinated. Cortical morphogenesis begins with proliferation of the new ciliary basal bodies (BBs) within meridional cortical rows of ciliary BBs, and with the local proliferation of BBs, which form the new oral apparatus (OA2), positioned subequatorialy and destined for prospective posterior daughter cell (opisthe). Prior to cytokinesis, two prospective daughter cells are of equal size and show metamery of their cortical patterns. We studied effects of 20 μM roscovitine (an inhibitor of several cyclin-dependent kinases) on the cell cycle progression of T. thermophila. We showed that roscovitine delayed cell division, delayed or arrested macronuclear division and induced increase of cell size and the number of BBs in the cortical rows. The increase in the number of BBs in cortical rows induced cell elongation which was proportional to the increase in cell surface area. There was uncoupling between this BBs proliferation which is continued during prolonged cell cycle and delayed cytokinesis, what resulted in topological alteration of the respective positions of the OA2 and of the contractile vacuole pores (CVPs). In roscovitine treated cells, the new OA2 was positioned subequatorialy, but the fission zone was shifted posterior to the equatorial plane of the cell and positioned across and in the extreme cases behind of the new OA2. This resulted in the formation of a large proter and small size opisthe. The roscovitine treatment induced a formation of a plethora of phenotypes of postdividing cells. We found that irrespective of changes in divisional morphogenesis induced by roscovitine treatment, all mature BBs were associated with the cdc14-like phosphatase. Taken together all these data indicate that during cell cycle of T. thermophila the normal morphology of the daughter cells depends on the proper division of micro- and macronucleus and on temporal control of BBs proliferation along the longitudinal rows, during OA2 stomatogenesis and during selection of BBs involved in differentiation of apical BBs (couplets) and cell division.
Kenneth H. Nicholls
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 113-117
https://doi.org/10.4467/16890027AP.12.009.0513Zoelucasa sablensis n. gen et n. sp. is a small heterotrophic fl agellate housed within a pyriform lorica of relatively large imbricate, circular siliceous scales. It was found in near-shore benthic sand/seawater samples of both the Pacific and Atlantic Oceans (west and east coasts of Canada; salinity = 32–33 ppt). The median length and width of the lorica was 18 and 11 μm, respectively (n = 29). This taxon lacks chloroplasts and swims with a slow zig-zag motion controlled by a short (5–7 μm long), anteriorly-directed flagellum and a longer trailing flagellum, 15–20 μm in length. Its classification within the phylum Cercozoa (most likely, Class Imbricatea) is tentative, as there are no known morphological homologues (discoidal, overlapping siliceous plate-scales forming a test or lorica enclosing a heterotrophic flagellate). Further study of cultured and wild material, including a search for other possible non-flagellate (e.g. amoeboid?) life history stages, TEM examination of cell sections, and rDNA sequencing will most certainly provide more opportunities for a justifi able classifi cation, possibly including a new Order.
Esra Elif Aydin, Won Je Lee
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 119-137
https://doi.org/10.4467/16890027AP.12.010.0514This is the first study of free-living heterotrophic flagellates in intertidal sediments of Saros Bay, Aegean Sea (Turkey). In order to contribute to an understanding of the geographic distribution of free-living marine heterotrophic flagellates, we investigated the diversity of heterotrophic flagellates occurring in the bay from 25th June 2010 to 10th October 2010. Thirty eight species from 30 genera of heterotrophic flagellates and one unidentifi ed taxon are reported with uninterpreted records based on light-microscopy. The records consist of one apusomonad, one cercomonad, two choanofl agellates, two cryptomonads, 12 euglenids, one heteroloboseid, one kathablepharid, three kinetoplastids, six stramenopiles, two thaumatomonads and seven of uncertain affinities. All of the morphospecies described here was previously reported elsewhere and appear to be cosmopolitan.
Luisa Baessolo, Leonardo David Fernández, Jaime Zapata, Ralf Meisterfeld
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 139-154
https://doi.org/10.4467/16890027AP.12.011.0515We investigate for the first time the species composition and community structure of lobose thecamoebians (Arcellinida) inhabiting an unpopulated and pristine island from the southeastern Pacific. Results revealed low alpha diversity and a high proportion of cosmopolitan species. One genus, four species and two subspecies were identified for the first time for southwestern South America. Further, four morphotypes were not identifi ed to species level, and one could not be identifi ed to species or genera level. They are probably endemics of this poorly studied and remote zone. These results were consistent with the moderate endemicity hypothesis of microbial biogeography. We hypothesized that the low diversity of species recorded on the island is due to selective colonization-extinction dynamics, processes that determines the low species richness of insular macro-organisms. However, this hypothesis needs to be evaluated in the future. Statistical analysis showed that testate amoebae were distributed in two discrete communities in the island. The first consisted of organisms inhabiting habitats located within a forest and the second by organisms inhabiting habitats located outside the forest. The suggested primary factor differentiating these both communities was the availability of appropriate habitat for the different species of testate amoebae.
Andrey N. Tsyganov, Stijn Temmerman, Pieter Ledeganck, Louis Beyens
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 155-167
https://doi.org/10.4467/16890027AP.12.012.0516Understanding the spatial distribution of soil protozoa under the snow cover is important for estimation of ecosystem responses to climate change and interpretation of results of field experiments. This work explores spatial patterns of soil testate amoebae under the snow cover at the plot scale (the range of metres) in arctic tundra (Qeqertarsuaq/Disko Island, West Greenland). To explain spatial patterns in abundance, species diversity and assemblage composition of testate amoebae, we measured microtopography, snow depth and substrate density. The results indicate that the abundance of active testate amoebae under the snow cover was quite low. The empty shell assemblage was characterised by the presence of linear spatial trends in the species composition across the site, whereas no patterns were detected within the plot. The distribution of the abundance and the species diversity were unstructured. The linear trends in the species composition corresponded to the site microtopography and were controlled by the topography-related soil moisture. Snow depth also affected the linear trends presumably by controlling soil temperatures. Overall, the results suggest that population processes do not generate spatial patterns in protozoan assemblages at the plot scale so that protozoan distribution can be considered random at macroscopically homogeneous plots.
Ľudovít Cagáň, Anna Plačková, Peter Bokor
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 169-177
https://doi.org/10.4467/16890027AP.12.013.0517Ostrinia nubilalis populations from Slovakia, Romania, Austria, Serbia and Germany were collected in the autumn when the insects were in the larval stage. These insects were then established as laboratory populations. The number of pupae and adults that developed was always higher in the Nosema pyrausta non-inoculated (uninfected) populations than in the populations treated by the pathogen N. pyrausta (infected). Significant differences were also found among the populations from different countries. Infected females laid significantly fewer eggs compared to uninfected females. The average time for pupal eclosion or adult emergence was not signifi cantly different between the uninfected and infected populations of O. nubilalis. However, it was found that the infected females laid their eggs significantly sooner as compared to the uninfected females (37.383 days compared to 40.089 days). Under the same conditions, populations from colder regions developed faster than those from warmer regions. The place of origin of the population did not significantly influence larval weight, larval length or pupal weight. However, larvae infected with N. pyrausta spores had signifi cantly lower weight (average 0.0797 g) than uninfected larvae (0.0901 g). With regard to pupal weight, the difference between the infected and uninfected individuals was not signifi cant. It was confi rmed that N. pyrausta from one European country can infect and infl uence host larvae originating in other countries. Although there have been several statistically significant interactions with regard to the country of origin and N. pyrausta infection, it was not believed that N. pyrausta from one country would have specific effects on the mortality, developmental rate and larval or pupal weight of O. nubilalis populations from different countries.
Biplob Kr. Modak, Ranatosh Kr. Adhikari, Saugata Basu, Durga P. Haldar
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 179-186
https://doi.org/10.4467/16890027AP.12.014.0518This paper deals with the morphology and life history of two new species of septate greganines (Apicomplexa: Conoidasida: Gregarinidae) of the genus Unilobus Théodoridès, Desportes & Jolivet, 1984, obtained from two tenebrionid beetles of West Bengal, India.These are Unilobus gonocephali n. sp. from Gonocephalum sp. (Insecta: Coleoptera: Tenebrionidae) and Unilobus scleroni n. sp. from Scleron irregulate (Insecta: Coleoptera: Tenebrionidae). Total length of U. gonocephali varies from 200–467 μm. Gametocysts spherical, 410 μm in average diameter, dehisces through 7–9 sporoducts. U. scleroni is comparatively smaller, total length varies from 61–232 μm. Gametocyst spherical with average diameter 350 μm, dehices through 10 to 12 sporoducts. The two new species share traits which define the genus such as the absence of epimerite, expanded protomerite and late association. These two described species are not only different from the previously described species, but also oocysts (= spores) entirely different from each other in characters like measurements, number of sporoduct and in host range. This communication also confi rmed the validity of the genus Unilobus Théodoridès, Desportes & Jolivet, 1984 and its placement under the family Gregarinidae Labbé, 1899.
Janina Kaczanowska, Mauryla Kiersnowska, Hanna Fabczak, Szymon Kaczanowski, Andrzej Kaczanowski
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 91-111
https://doi.org/10.4467/16890027AP.12.008.0512During cell cycle of a ciliate Tetrahymena thermophila the divisions of micro- and macronucleus, cortical morphogenesis and cytokinesis are temporarily coordinated. Cortical morphogenesis begins with proliferation of the new ciliary basal bodies (BBs) within meridional cortical rows of ciliary BBs, and with the local proliferation of BBs, which form the new oral apparatus (OA2), positioned subequatorialy and destined for prospective posterior daughter cell (opisthe). Prior to cytokinesis, two prospective daughter cells are of equal size and show metamery of their cortical patterns. We studied effects of 20 μM roscovitine (an inhibitor of several cyclin-dependent kinases) on the cell cycle progression of T. thermophila. We showed that roscovitine delayed cell division, delayed or arrested macronuclear division and induced increase of cell size and the number of BBs in the cortical rows. The increase in the number of BBs in cortical rows induced cell elongation which was proportional to the increase in cell surface area. There was uncoupling between this BBs proliferation which is continued during prolonged cell cycle and delayed cytokinesis, what resulted in topological alteration of the respective positions of the OA2 and of the contractile vacuole pores (CVPs). In roscovitine treated cells, the new OA2 was positioned subequatorialy, but the fission zone was shifted posterior to the equatorial plane of the cell and positioned across and in the extreme cases behind of the new OA2. This resulted in the formation of a large proter and small size opisthe. The roscovitine treatment induced a formation of a plethora of phenotypes of postdividing cells. We found that irrespective of changes in divisional morphogenesis induced by roscovitine treatment, all mature BBs were associated with the cdc14-like phosphatase. Taken together all these data indicate that during cell cycle of T. thermophila the normal morphology of the daughter cells depends on the proper division of micro- and macronucleus and on temporal control of BBs proliferation along the longitudinal rows, during OA2 stomatogenesis and during selection of BBs involved in differentiation of apical BBs (couplets) and cell division.
Kenneth H. Nicholls
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 113-117
https://doi.org/10.4467/16890027AP.12.009.0513Zoelucasa sablensis n. gen et n. sp. is a small heterotrophic fl agellate housed within a pyriform lorica of relatively large imbricate, circular siliceous scales. It was found in near-shore benthic sand/seawater samples of both the Pacific and Atlantic Oceans (west and east coasts of Canada; salinity = 32–33 ppt). The median length and width of the lorica was 18 and 11 μm, respectively (n = 29). This taxon lacks chloroplasts and swims with a slow zig-zag motion controlled by a short (5–7 μm long), anteriorly-directed flagellum and a longer trailing flagellum, 15–20 μm in length. Its classification within the phylum Cercozoa (most likely, Class Imbricatea) is tentative, as there are no known morphological homologues (discoidal, overlapping siliceous plate-scales forming a test or lorica enclosing a heterotrophic flagellate). Further study of cultured and wild material, including a search for other possible non-flagellate (e.g. amoeboid?) life history stages, TEM examination of cell sections, and rDNA sequencing will most certainly provide more opportunities for a justifi able classifi cation, possibly including a new Order.
Esra Elif Aydin, Won Je Lee
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 119-137
https://doi.org/10.4467/16890027AP.12.010.0514This is the first study of free-living heterotrophic flagellates in intertidal sediments of Saros Bay, Aegean Sea (Turkey). In order to contribute to an understanding of the geographic distribution of free-living marine heterotrophic flagellates, we investigated the diversity of heterotrophic flagellates occurring in the bay from 25th June 2010 to 10th October 2010. Thirty eight species from 30 genera of heterotrophic flagellates and one unidentifi ed taxon are reported with uninterpreted records based on light-microscopy. The records consist of one apusomonad, one cercomonad, two choanofl agellates, two cryptomonads, 12 euglenids, one heteroloboseid, one kathablepharid, three kinetoplastids, six stramenopiles, two thaumatomonads and seven of uncertain affinities. All of the morphospecies described here was previously reported elsewhere and appear to be cosmopolitan.
Luisa Baessolo, Leonardo David Fernández, Jaime Zapata, Ralf Meisterfeld
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 139-154
https://doi.org/10.4467/16890027AP.12.011.0515We investigate for the first time the species composition and community structure of lobose thecamoebians (Arcellinida) inhabiting an unpopulated and pristine island from the southeastern Pacific. Results revealed low alpha diversity and a high proportion of cosmopolitan species. One genus, four species and two subspecies were identified for the first time for southwestern South America. Further, four morphotypes were not identifi ed to species level, and one could not be identifi ed to species or genera level. They are probably endemics of this poorly studied and remote zone. These results were consistent with the moderate endemicity hypothesis of microbial biogeography. We hypothesized that the low diversity of species recorded on the island is due to selective colonization-extinction dynamics, processes that determines the low species richness of insular macro-organisms. However, this hypothesis needs to be evaluated in the future. Statistical analysis showed that testate amoebae were distributed in two discrete communities in the island. The first consisted of organisms inhabiting habitats located within a forest and the second by organisms inhabiting habitats located outside the forest. The suggested primary factor differentiating these both communities was the availability of appropriate habitat for the different species of testate amoebae.
Andrey N. Tsyganov, Stijn Temmerman, Pieter Ledeganck, Louis Beyens
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 155-167
https://doi.org/10.4467/16890027AP.12.012.0516Understanding the spatial distribution of soil protozoa under the snow cover is important for estimation of ecosystem responses to climate change and interpretation of results of field experiments. This work explores spatial patterns of soil testate amoebae under the snow cover at the plot scale (the range of metres) in arctic tundra (Qeqertarsuaq/Disko Island, West Greenland). To explain spatial patterns in abundance, species diversity and assemblage composition of testate amoebae, we measured microtopography, snow depth and substrate density. The results indicate that the abundance of active testate amoebae under the snow cover was quite low. The empty shell assemblage was characterised by the presence of linear spatial trends in the species composition across the site, whereas no patterns were detected within the plot. The distribution of the abundance and the species diversity were unstructured. The linear trends in the species composition corresponded to the site microtopography and were controlled by the topography-related soil moisture. Snow depth also affected the linear trends presumably by controlling soil temperatures. Overall, the results suggest that population processes do not generate spatial patterns in protozoan assemblages at the plot scale so that protozoan distribution can be considered random at macroscopically homogeneous plots.
Ľudovít Cagáň, Anna Plačková, Peter Bokor
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 169-177
https://doi.org/10.4467/16890027AP.12.013.0517Ostrinia nubilalis populations from Slovakia, Romania, Austria, Serbia and Germany were collected in the autumn when the insects were in the larval stage. These insects were then established as laboratory populations. The number of pupae and adults that developed was always higher in the Nosema pyrausta non-inoculated (uninfected) populations than in the populations treated by the pathogen N. pyrausta (infected). Significant differences were also found among the populations from different countries. Infected females laid significantly fewer eggs compared to uninfected females. The average time for pupal eclosion or adult emergence was not signifi cantly different between the uninfected and infected populations of O. nubilalis. However, it was found that the infected females laid their eggs significantly sooner as compared to the uninfected females (37.383 days compared to 40.089 days). Under the same conditions, populations from colder regions developed faster than those from warmer regions. The place of origin of the population did not significantly influence larval weight, larval length or pupal weight. However, larvae infected with N. pyrausta spores had signifi cantly lower weight (average 0.0797 g) than uninfected larvae (0.0901 g). With regard to pupal weight, the difference between the infected and uninfected individuals was not signifi cant. It was confi rmed that N. pyrausta from one European country can infect and infl uence host larvae originating in other countries. Although there have been several statistically significant interactions with regard to the country of origin and N. pyrausta infection, it was not believed that N. pyrausta from one country would have specific effects on the mortality, developmental rate and larval or pupal weight of O. nubilalis populations from different countries.
Biplob Kr. Modak, Ranatosh Kr. Adhikari, Saugata Basu, Durga P. Haldar
Acta Protozoologica, Volume 51, Issue 2, 2012, pp. 179-186
https://doi.org/10.4467/16890027AP.12.014.0518This paper deals with the morphology and life history of two new species of septate greganines (Apicomplexa: Conoidasida: Gregarinidae) of the genus Unilobus Théodoridès, Desportes & Jolivet, 1984, obtained from two tenebrionid beetles of West Bengal, India.These are Unilobus gonocephali n. sp. from Gonocephalum sp. (Insecta: Coleoptera: Tenebrionidae) and Unilobus scleroni n. sp. from Scleron irregulate (Insecta: Coleoptera: Tenebrionidae). Total length of U. gonocephali varies from 200–467 μm. Gametocysts spherical, 410 μm in average diameter, dehisces through 7–9 sporoducts. U. scleroni is comparatively smaller, total length varies from 61–232 μm. Gametocyst spherical with average diameter 350 μm, dehices through 10 to 12 sporoducts. The two new species share traits which define the genus such as the absence of epimerite, expanded protomerite and late association. These two described species are not only different from the previously described species, but also oocysts (= spores) entirely different from each other in characters like measurements, number of sporoduct and in host range. This communication also confi rmed the validity of the genus Unilobus Théodoridès, Desportes & Jolivet, 1984 and its placement under the family Gregarinidae Labbé, 1899.
Publication date: 04.06.2012
Editor-in-Chief: Krzysztof Wiąckowski
Sabine Agatha, Paul Simon
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 1-19
https://doi.org/10.4467/16890027AP.12.001.0384Tintinnids (Ciliophora: Spirotricha: Tintinnina) are occasionally the dominant ciliates in the marine plankton. The tintinnid loricae are minute artworks fascinating scientists for more than 230 years, but their chemical composition remained unclear, viz., chitinous or proteinaceous substances were discussed. Since sedimenting loricae contribute to the flux of elements and organic compounds in the oceans, knowledge about their nature is necessary in assessing their ecological role. Previous techniques and new methods, e.g. enzymatic digestion and high-resolution transmission electron microscopy, are applied in the present study. A chitinous nature of the loricae is rejected by the Van-Wisselingh test and failure of chitinase digestion. Only proteins might show a resistance against strong hot bases (KOH at 160°C for ~ 40 min. in tintinnid loricae) similar to that of chitin. Actually, the presence of nitrogen in the EDX analyses and the digestion of at least some loricae by proteinase K strongly indicate a proteinaceous nature. Furthermore, the crystal lattice revealed by high-resolution TEM in Eutintinnus loricae is similar to the proteinaceous surface layer (S-layer) of archaea, and the striation recognizable in transverse sections of Eutintinnus loricae has a periodicity resembling that of the crystalline proteins in the extruded trichocysts of Paramecium and Frontonia. The proteolytic resistance of some loricae does not reject the idea of a proteinaceous nature, as proteins in S-layers of some archaea and in most naturally occurring prions show comparable reactions. The data from the present study and the literature indicate proteins in the loricae of thirteen genera. Differences in the proteolytic resistance and staining properties between genera and congeners are probably due to deviations in the protein composition and the additional substances, e.g. lipids, carbohydrates. At the present state of knowledge, correlations between lorica structure, wall texture, ultrastructure of the lorica forming granules, and the histochemical and enzymatic findings are not evident. Therefore, further studies are required to estimate the taxonomic significance of these features and the ecological role of sedimenting loricae.
Kenneth H. Nicholls
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 21-28
https://doi.org/10.4467/16890027AP.12.002.0385Several Ontario (Canada) populations of the “heliozoan-like” protist Belonocystis Rainer, 1968 were studied to help elucidate the taxonomic position of this genus relative to other rhizarian protists with fine pseudopodia. The Ontario material presently includes two distinct species – B. tubistella Rainer and B. quadrangularis n. sp., described here as a new species based on cell morphology and microstructure of the spiny investiture encasing its cell. The organic nature of the spiny structures of both species has been confirmed by their dissolution in 6% sodium hypochlorite solution. Median cell diameters of B. tubistella and B. quadrangularis were 10.5 μm and 7 μm, respectively. As revealed by transmission electron microscopy, the spine bases in B. tubistella consisted of a complex structure of four curved ribs interconnected by a membranous sheet replete with closely-appressed, large circular to elliptical pores, while in B. quadrangularis the spine bases consisted of a simple four-cornered “pyramid” of struts that supported the main shaft of the spine. These findings strengthen the status of the genus Belonocystis and it placement outside the realm of the Centrohelida and Rotosphaerida.
Ying Pan, Liqiong Li, Chen Shao, Xiaozhong Hu, Honggang Ma, Khaled A. S. Alrasheid
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 29-38
https://doi.org/10.4467/16890027AP.12.003.0386Euplotes balteatus (Dujardin, 1841) Kahl 1932, collected from coastal waters near Qingdao, northern China, was investigated using live observation and silver staining methods. An improved diagnosis and morphometric data are provided. Euplotes balteatus can be identified by the following combination of characters: 10 frontoventral cirri, 2 widely separated marginal cirri, 2 fine caudal cirri, 8 dorsal kineties and a double-eurystomus type silverline system. Its morphogenesis, which is similar to that of several congeners, can be summarized as follows: (1) the opisthe’s oral primordium appears de novo under the pellicle whereas the old oral apparatus is retained by the proter; (2) two groups of frontoventral transverse cirral anlagen, each with five streaks, occur de novo and then develop into the frontoventral and transverse cirri separately according to the formula of “3:3:3:3:2” from left to right; (3) the anlagen for the marginal cirri occur de novo near the parental oral apparatus; (4) migratory cirri of both dividers derive from the anlagen near the paroral membrane; (5) the dorsal kinety anlagen come from dedifferentiation of the parental structures in the mid-body region; (6) caudal cirri are formed at the posterior ends of the two rightmost dorsal kineties. In the light of the present findings, it was concluded that the Antarctic population of E. balteatus reported by Song and Wilbert (2002) was misidentified. A new species, Euplotes wilberti nov. spec., is established for this population.
Peter Vďačný, Eva Tirjaková
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 39-52
https://doi.org/10.4467/16890027AP.12.004.0387The present work describes the morphology and morphometry of a freshwater ciliate, Zosterodasys transversus, using live observation and protargol impregnation. The population from the River Ipeľ, Slovakia is designated as a neotype because (i) no type material is available from the species described by Kahl (1928); (ii) the neotype is consistent with Z. transversus as described by Kahl (1928); (iii) the neotype is from the same biogeographic region as Kahl’s (1928) populations; and (iv) there are several similar species (e.g., Z. agamalievi) whose identity is threatened by the species to be neotypified. The main features of Z. transversus are: (i) a body size of 120–240 × 50–115 μm in vivo; (ii) a broadly to narrowly obovate or elliptical body; (iii) a spherical to very narrowly ellipsoidal macronucleus with a single globular micronucleus nearby; (iv) several scattered contractile vacuoles; (v) an average of 82 ciliary rows, most of which are interrupted by a synhymenium incompletely encircling the body; and (vi) an average of 14 nematodesmal rods strengthening walls of the cyrtos. In the well-growing neotype population, a single cell of a mirror-image type was found. Most of the structures of this monster specimen are similar to those from ordinary cells, except for the double cytostome and cyrtos.
Anatoly Bobrov, Satoshi Shimano, Yuri A. Mazei
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 55-63
Two new species of Deharvengia and Assulina are described from samples in the mountain forests of Honshu Is. (Japan). Morphometric analysis showed low variability of their morphological characteristics with coefficients of variation ranging between 1.4 and 9.1% for the two new species. An amended description of the genus Deharvengia is provided
Denis V. Tikhonenkov, Alexander P. Mylnikov, Ying Chun Gong, Wei Song Feng, Yuri A. Mazei
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 65-79
We studied the diversity of heterotrophic flagellates from the sandy sediments of the Yangtze River, sandy and silty sediments of Donghu Lake, soil, moss and litter from the Luojiashan and Moshan hills as well as litter from the floodplain near Donghu Lake in April 2010. Sixty-seven heterotrophic flagellate species were identified by means of phase and interference contrast light microscopy and transmission electron microscopy. The majority of the observed flagellates were bacterivorous. Local species richness of river sediment communities was significantly lower than that of lake sediments and terrestrial habitats. The communities from the terrestrial habitats were more heterogeneous than those from freshwater sediments. Common species for the aquatic habitats were Rhynchomonas nasuta, Paraphysomonas sp., Neobodo designis, N. curvifilis, Bodo saltans and Spumella spp. In the soils only Spumella spp. was found in the majority of samples. Most characteristic taxa for the lake sediments were Helkesimastix faecicola, Petalomonas minuta, P. pusilla, Diphylleia rotans, Amastigomonas caudata. Amoeboflagellates such as Cercomonas angustus, C. granulifera, Paracercomonas crassicauda were specific for the terrestrial habitats. There were no specific taxa in the river sediments. The majority of the heterotrophic flagellates identified in this survey have been noted in China earlier. They are common (and usually predominant) for other regions in both freshwater and soil habitats.
Ján Jamriška, F. Javier López, David Modrý
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 81-85
A new species of isosporoid coccidia (Apicomplexa: Eimeriidae) is described from captive Himalayan Black Bulbul Hypsipetes leucocephalus (Passeriformes: Pycnonotidae). Sporulated oocysts of Isospora annthomassonae n. sp. are subspherical to slightly ellipsoidal 32.0 ± 1.5 × 29.4 ± 1.3 (30–35 × 27–31) μm. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are broadly ellipsoidal, 24.6 ± 1.4 × 12.9 ± 0.7 (22–28 × 12–14) μm, with Stieda and substiedal bodies. Sporocyst residuum is broadly ellipsoidal, 11.3 ± 0.8 × 9.5 ± 0.7 (9–13 × 8–11) μm, composed of hundreds of small granules. Sporozoites are elongate and slightly curved, each with two refractile bodies.
David M. Wilkinson
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 87-90
Sabine Agatha, Paul Simon
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 1-19
https://doi.org/10.4467/16890027AP.12.001.0384Tintinnids (Ciliophora: Spirotricha: Tintinnina) are occasionally the dominant ciliates in the marine plankton. The tintinnid loricae are minute artworks fascinating scientists for more than 230 years, but their chemical composition remained unclear, viz., chitinous or proteinaceous substances were discussed. Since sedimenting loricae contribute to the flux of elements and organic compounds in the oceans, knowledge about their nature is necessary in assessing their ecological role. Previous techniques and new methods, e.g. enzymatic digestion and high-resolution transmission electron microscopy, are applied in the present study. A chitinous nature of the loricae is rejected by the Van-Wisselingh test and failure of chitinase digestion. Only proteins might show a resistance against strong hot bases (KOH at 160°C for ~ 40 min. in tintinnid loricae) similar to that of chitin. Actually, the presence of nitrogen in the EDX analyses and the digestion of at least some loricae by proteinase K strongly indicate a proteinaceous nature. Furthermore, the crystal lattice revealed by high-resolution TEM in Eutintinnus loricae is similar to the proteinaceous surface layer (S-layer) of archaea, and the striation recognizable in transverse sections of Eutintinnus loricae has a periodicity resembling that of the crystalline proteins in the extruded trichocysts of Paramecium and Frontonia. The proteolytic resistance of some loricae does not reject the idea of a proteinaceous nature, as proteins in S-layers of some archaea and in most naturally occurring prions show comparable reactions. The data from the present study and the literature indicate proteins in the loricae of thirteen genera. Differences in the proteolytic resistance and staining properties between genera and congeners are probably due to deviations in the protein composition and the additional substances, e.g. lipids, carbohydrates. At the present state of knowledge, correlations between lorica structure, wall texture, ultrastructure of the lorica forming granules, and the histochemical and enzymatic findings are not evident. Therefore, further studies are required to estimate the taxonomic significance of these features and the ecological role of sedimenting loricae.
Kenneth H. Nicholls
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 21-28
https://doi.org/10.4467/16890027AP.12.002.0385Several Ontario (Canada) populations of the “heliozoan-like” protist Belonocystis Rainer, 1968 were studied to help elucidate the taxonomic position of this genus relative to other rhizarian protists with fine pseudopodia. The Ontario material presently includes two distinct species – B. tubistella Rainer and B. quadrangularis n. sp., described here as a new species based on cell morphology and microstructure of the spiny investiture encasing its cell. The organic nature of the spiny structures of both species has been confirmed by their dissolution in 6% sodium hypochlorite solution. Median cell diameters of B. tubistella and B. quadrangularis were 10.5 μm and 7 μm, respectively. As revealed by transmission electron microscopy, the spine bases in B. tubistella consisted of a complex structure of four curved ribs interconnected by a membranous sheet replete with closely-appressed, large circular to elliptical pores, while in B. quadrangularis the spine bases consisted of a simple four-cornered “pyramid” of struts that supported the main shaft of the spine. These findings strengthen the status of the genus Belonocystis and it placement outside the realm of the Centrohelida and Rotosphaerida.
Ying Pan, Liqiong Li, Chen Shao, Xiaozhong Hu, Honggang Ma, Khaled A. S. Alrasheid
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 29-38
https://doi.org/10.4467/16890027AP.12.003.0386Euplotes balteatus (Dujardin, 1841) Kahl 1932, collected from coastal waters near Qingdao, northern China, was investigated using live observation and silver staining methods. An improved diagnosis and morphometric data are provided. Euplotes balteatus can be identified by the following combination of characters: 10 frontoventral cirri, 2 widely separated marginal cirri, 2 fine caudal cirri, 8 dorsal kineties and a double-eurystomus type silverline system. Its morphogenesis, which is similar to that of several congeners, can be summarized as follows: (1) the opisthe’s oral primordium appears de novo under the pellicle whereas the old oral apparatus is retained by the proter; (2) two groups of frontoventral transverse cirral anlagen, each with five streaks, occur de novo and then develop into the frontoventral and transverse cirri separately according to the formula of “3:3:3:3:2” from left to right; (3) the anlagen for the marginal cirri occur de novo near the parental oral apparatus; (4) migratory cirri of both dividers derive from the anlagen near the paroral membrane; (5) the dorsal kinety anlagen come from dedifferentiation of the parental structures in the mid-body region; (6) caudal cirri are formed at the posterior ends of the two rightmost dorsal kineties. In the light of the present findings, it was concluded that the Antarctic population of E. balteatus reported by Song and Wilbert (2002) was misidentified. A new species, Euplotes wilberti nov. spec., is established for this population.
Peter Vďačný, Eva Tirjaková
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 39-52
https://doi.org/10.4467/16890027AP.12.004.0387The present work describes the morphology and morphometry of a freshwater ciliate, Zosterodasys transversus, using live observation and protargol impregnation. The population from the River Ipeľ, Slovakia is designated as a neotype because (i) no type material is available from the species described by Kahl (1928); (ii) the neotype is consistent with Z. transversus as described by Kahl (1928); (iii) the neotype is from the same biogeographic region as Kahl’s (1928) populations; and (iv) there are several similar species (e.g., Z. agamalievi) whose identity is threatened by the species to be neotypified. The main features of Z. transversus are: (i) a body size of 120–240 × 50–115 μm in vivo; (ii) a broadly to narrowly obovate or elliptical body; (iii) a spherical to very narrowly ellipsoidal macronucleus with a single globular micronucleus nearby; (iv) several scattered contractile vacuoles; (v) an average of 82 ciliary rows, most of which are interrupted by a synhymenium incompletely encircling the body; and (vi) an average of 14 nematodesmal rods strengthening walls of the cyrtos. In the well-growing neotype population, a single cell of a mirror-image type was found. Most of the structures of this monster specimen are similar to those from ordinary cells, except for the double cytostome and cyrtos.
Anatoly Bobrov, Satoshi Shimano, Yuri A. Mazei
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 55-63
Two new species of Deharvengia and Assulina are described from samples in the mountain forests of Honshu Is. (Japan). Morphometric analysis showed low variability of their morphological characteristics with coefficients of variation ranging between 1.4 and 9.1% for the two new species. An amended description of the genus Deharvengia is provided
Denis V. Tikhonenkov, Alexander P. Mylnikov, Ying Chun Gong, Wei Song Feng, Yuri A. Mazei
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 65-79
We studied the diversity of heterotrophic flagellates from the sandy sediments of the Yangtze River, sandy and silty sediments of Donghu Lake, soil, moss and litter from the Luojiashan and Moshan hills as well as litter from the floodplain near Donghu Lake in April 2010. Sixty-seven heterotrophic flagellate species were identified by means of phase and interference contrast light microscopy and transmission electron microscopy. The majority of the observed flagellates were bacterivorous. Local species richness of river sediment communities was significantly lower than that of lake sediments and terrestrial habitats. The communities from the terrestrial habitats were more heterogeneous than those from freshwater sediments. Common species for the aquatic habitats were Rhynchomonas nasuta, Paraphysomonas sp., Neobodo designis, N. curvifilis, Bodo saltans and Spumella spp. In the soils only Spumella spp. was found in the majority of samples. Most characteristic taxa for the lake sediments were Helkesimastix faecicola, Petalomonas minuta, P. pusilla, Diphylleia rotans, Amastigomonas caudata. Amoeboflagellates such as Cercomonas angustus, C. granulifera, Paracercomonas crassicauda were specific for the terrestrial habitats. There were no specific taxa in the river sediments. The majority of the heterotrophic flagellates identified in this survey have been noted in China earlier. They are common (and usually predominant) for other regions in both freshwater and soil habitats.
Ján Jamriška, F. Javier López, David Modrý
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 81-85
A new species of isosporoid coccidia (Apicomplexa: Eimeriidae) is described from captive Himalayan Black Bulbul Hypsipetes leucocephalus (Passeriformes: Pycnonotidae). Sporulated oocysts of Isospora annthomassonae n. sp. are subspherical to slightly ellipsoidal 32.0 ± 1.5 × 29.4 ± 1.3 (30–35 × 27–31) μm. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are broadly ellipsoidal, 24.6 ± 1.4 × 12.9 ± 0.7 (22–28 × 12–14) μm, with Stieda and substiedal bodies. Sporocyst residuum is broadly ellipsoidal, 11.3 ± 0.8 × 9.5 ± 0.7 (9–13 × 8–11) μm, composed of hundreds of small granules. Sporozoites are elongate and slightly curved, each with two refractile bodies.
David M. Wilkinson
Acta Protozoologica, Volume 51, Issue 1, 2012, pp. 87-90
Publication date: 2011
Editor-in-Chief: Krzysztof Wiąckowski
Chen Shao, Weibo Song, Khaled A. S. Al-Rasheid, Helmut Berger
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 263-287
https://doi.org/10.4467/16890027AP.11.025.0062The morphology, the infraciliature, and two stages of physiological reorganization of Hemigastrostyla elongata spec. nov.,isolated from the Yellow Sea near Qingdao (China), are described. The new species differs from the type H. stenocephala, inter alia, by the length of the dorsal bristles and the position of the pretransverse ventral cirri; from H. enigmatica by the number of caudal cirri; and from H. para-enigmatica spec. nov. – established for the H. enigmatica populations from the Yellow Sea – by the arrangement of the postoral ventral cirri and the cortical granulation. A key to the Hemigastrostyla species and some other 18-cirri hypotrichs is provided. Hemigastrostyla szaboi is fixed as type species of Heterooxytricha gen. nov. because the type population lacks the extra cirri which are characteristic for Hemigastrostyla. In addition, Oxytricha geleii is assigned to this new genus, whose species have, like many oxytrichids, 18 frontal-ventraltransverse cirri, but a Gonostomum dorsal kinety pattern. The old, large, and difficult genus Oxytricha is briefly reviewed, mainly on the basis of the dorsal kinety pattern. Very likely, only species with the Oxytricha pattern belong to this genus. Oxytricha marcili and O. pseudofurcata, which have the Urosomoida kinety pattern (i.e. kinety 3 fragmentation lacking), are transferred to Urosomoida which is, inter alia, defined by a more or less distinctly reduced number of ventral and transverse cirri. Some other Oxytricha species with this kinety pattern (O. islandica, O. lanceolata, O. pseudosimilis, O. setigera) are not transferred to Urosomoida, but preliminarily classified as incertae sedis in Oxytricha, because they have the full set of 18 cirri. The available molecular data on O. lanceolata indicate that this type of 18-cirri hypotrichs likely needs a genus of its own because O. lanceolata does not cluster with O. granulifera, type of this genus. The marine Actinotricha saltans, classified for a very long time in Oxytricha, seems to be a non-dorsomarginalian hypotrich according to molecular data, justifying the reactivation of the old genus Actinotricha. Oxytricha shii has a multiple dorsal kinety 3 fragmentation, three dorsomarginal rows, and the undulating membranes arranged in the Cyrtohymena pattern, strongly indicating that it is a member of the subgenus Cyrtohymena (Cyrtohymenides). This brief review is a further step to unravel the complicated systematics of the old, but still little-known genus Oxytricha. The following new combinations are made in this paper: Cyrtohymena (Cyrtohymenides) shii (Shi et al., 1997) comb. nov.; Heterooxytricha szaboi (Wilbert and Song, 2005) comb. nov.; Heterooxytricha geleii (Wilbert, 1986) comb. nov.; Urosomoida marcili (Paiva and Silva-Neto, 2004) comb. nov.; Urosomoida pseudofurcata (Berger, 1999) comb. nov.
Jae-Ho Jung, Ye-Seul Baek, Sanghee Kim, Han-Gu Choi, Gi-Sik Min
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 289-300
https://doi.org/10.4467/16890027AP.11.026.0063In this study, a new marine urostylid ciliate, Metaurostylopsis antarctica nov. spec. collected from the Antarctic Ocean was investigated using morphological, morphometrical, and molecular methods. Metaurostylopsis antarctica nov. spec. is characterized as follows: slender to ellipsoid form in body shape; two types of cortical granules, ellipsoid large one (type I, yellow-green, 1.5 × 1 μm) in rows along dorsal kineties and cirri, circular small one (type II, colourless, 0.3 μm in diameter) scattered throughout whole body; 19–24 adoral membranelles, 4 frontal cirri, 2–5 frontoterminal cirri, 1 buccal and 2 transverse cirri; 3–5 midventral pairs, 10–15 cirri of midventral row; 1 right and 2 left marginal rows; 3 dorsal kineties; about 43 macronuclear nodules. This new species mainly differs from the congeners by the number of marginal rows (1 vs. 3 or more on right side; 2 vs. 3 or more on left side). In addition, proter’s oral primordium developed on the right side of the oral cavity (vs. in center of oral cavity), and the rightmost anlage splits into two parts, nam ely, the frontoterminal cirri and a transverse cirrus (vs. only frontoterminal cirri). Inter-specific dissimilarities of the SSU rRNA gene between the congeners range from 3.3 to 4.4%.
Xuming Pan, Chen Shao, Honggang Ma, Xinpeng Fan, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj, Xiaozhong Hu
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 301-310
https://doi.org/10.4467/16890027AP.11.027.0064The morphology and infraciliature of two marine scuticociliates, Pleuronema puytoraci Grolière and Detcheva, 1974, and Parauronema longum Song, 1995, collected from China, were investigated using live observation and protargol impregnation methods. Based on the data obtained for the China population, new information of the living morphology of Pleuronema puytoraci is documented and details of the complete infraciliature is available for the first time. The stomatogenesis of Parauronema longum is basically similar to that of its congeners and can be summarized as follows: membranelle 1, membranelle 2 and the scutica of the opisthe originate from the parental paroral membrane, whereas membranelle 3 of the opisthe develops from the parental scutica; the paroral membrane originates from the parental paroral membrane.
Karolina Lukášová, Jaroslav Holuša
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 311-318
https://doi.org/10.4467/16890027AP.11.028.0065Changes in Gregarina typographi Fuchs, 1915 (Eugregarinorida: Gregarinidae) infection levels were studied in a population of the bark beetle Ips typographus (L., 1758) (Coleoptera: Curculionidae), which lives in association with Norway spruce. Beetles were repeatedly collected from three logs of trap trees during 2009 and 2010 at one study site in the Czech Republic with a high level of G. typographi infection (seasonal mean of 15.7% in 2009 and 19.8% in 2010). Infection levels did not differ statistically between sexes, logs, and trap trees but did differ among sampling dates. During the beetle reproductive period, the infection levels nearly doubled in 2009 (from 10.7 to 19.8%) and more than tripled in 2010 (from 9.3 to 31.3%). We infer that the continuous increase in the G. typographi infection level within each of the two years resulted from transmission among beetles in nuptial chambers during the May–June reproductive and egg-laying period.
Tim Snelling, Eric Pinloche, Hilary J. Worgan, Jamie Newbold, Neil R. McEwan
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 319-326
https://doi.org/10.4467/16890027AP.11.029.0066Single cell morphotypes of the species Triadinium caudatum and Spirodinium equi, together with a representative of the genus Blepharocorys (Blepharocorys sp.) were used for phylogenetic analysis based on their 18S rRNA genes. Spirodinium equi clustered with sequences already described for the entodiniomorphs isolated from horses and the Blepharocorys sp. also grouped within the Entodiniomorphida clade, although both sequences were distinct from those described from rumen ciliates. Triadinium caudatum clustered within the Vestibuliferida, and most closely to that of Paraisotricha, only other member of this order which has been described in the horse. It was concluded that although members of the orders Entodiniomorphida and Vestibuliferida are present in the equine gut, and that they share an ancient linage with their rumen counterparts, they are ancestrally different groups.
Sónia Rocha, Graça Casal, Patrícia Matos, Edilson Rodrigues Matos, Mohamed A. Dkhil, Carlos Azevedo
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 327-338
https://doi.org/10.4467/16890027AP.11.030.0067A fish-infecting myxosporean was found in the urinary bladder of the teleostean Colomesus psittacus, collected from the Amazon River, Brazil. Specimens were sampled in three different periods: May and June, with water temperature ranging from 18–23ºC; August, with water temperature ranging from 24–28ºC; and November and December, with water temperature ranging from 29–32ºC. Upon observation, several fish displayed abnormal behaviour, consisting of erratic movements, and mortality was recorded among them. Necropsy of all sampled fishes revealed hypertrophy of the urinary bladder only among specimens previously displaying the irregular behaviour. Microscopic analysis of this organ confirmed the parasitic infection, resulting in the observation of spores floating free in the urine, and numerous plasmodia attached to the epithelium of the urinary bladder. Light and ultrastructural studies allowed recognition of the spores and plasmodia morphological characteristics. Coelozoic plasmodia were polysporic with varying organizational structure, according to the sampling period. Spores were equilaterally triangular with rounded ends in valvar view, measuring 8.8 ± 0.4 μm (n = 30) in length and 8.4 ± 0.5 μm (n = 30) in width, and displaying a ridge surface pattern. Two polar capsules were observed in the anterior end of the spores, measuring 3.1–3.2 μm in diameter. The spores were morphologically identified as belonging to the recently described genus Triangulamyxa. Further observation and comparison to the morphological features described for Triangulamyxa amazonica, the only other species within this genus, allowed us to conclude our parasite as a new species, herein named Triangulamyxa psittaca sp. nov. from the Amazon River, Brazil. Also, three different stages were distinguished in the plasmodium evolution, based on the observed morphological features at the three sampling periods. Fish sampled during May and June displayed small plasmodia (up to ~ 15–20 μm long), containing early stages of sporogenic development. Fish sampled during November and December presented larger plasmodia (up to ~ 850 μm long), which appeared flattened against and lining the urinary bladder epithelial cells and contained the later stages of sporogenic development, including some mature spores. Fish sampled during August presented plasmodia displaying intermediate morphological features between those observed in infected fish from the other sampling periods. Several immature and mature spores were among the different developmental stages. The parasite-host interface evolution is described throughout the different observed stages, with emphasis on the formation of septate junctions. Considering several previous reports, as well as the different environmental conditions during the sampling periods, the plasmodium development here described appears to be influenced by environmental factors, namely water temperature.
Toshimasa Kobayashi, Nobuyuki Nakano, Takaaki Muto, Yoshinari Endo
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 339-343
https://doi.org/10.4467/16890027AP.11.031.0068Suctorians of the genus Ephelota are stalked ciliates and ectocommensals of marine invertebrates and plants. Ephelota gigantea has long been known as a major nuisance to the cultured seaweed industries in the coastal area of northeastern Japan. However, little is known about its life history, so in situ growth experiments were performed in the vicinity of wakame (Undaria pinnatifida) long-line culture in Iwate Prefecture, and the development of swarmers was investigated in the laboratory. The stalk elongated first, followed by enlargement of body length and body width, with body width increasing linearly with time. Over 5–6 days, E. gigantea increased 4–5-fold by external budding. Such an experiment was carried out for the first time for E. gigantea and possibly for any Ephelota species. The information obtained is important not only in understanding the life history of this species but also for understanding the interactions with host organisms.
Chen Shao, Weibo Song, Khaled A. S. Al-Rasheid, Helmut Berger
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 263-287
https://doi.org/10.4467/16890027AP.11.025.0062The morphology, the infraciliature, and two stages of physiological reorganization of Hemigastrostyla elongata spec. nov.,isolated from the Yellow Sea near Qingdao (China), are described. The new species differs from the type H. stenocephala, inter alia, by the length of the dorsal bristles and the position of the pretransverse ventral cirri; from H. enigmatica by the number of caudal cirri; and from H. para-enigmatica spec. nov. – established for the H. enigmatica populations from the Yellow Sea – by the arrangement of the postoral ventral cirri and the cortical granulation. A key to the Hemigastrostyla species and some other 18-cirri hypotrichs is provided. Hemigastrostyla szaboi is fixed as type species of Heterooxytricha gen. nov. because the type population lacks the extra cirri which are characteristic for Hemigastrostyla. In addition, Oxytricha geleii is assigned to this new genus, whose species have, like many oxytrichids, 18 frontal-ventraltransverse cirri, but a Gonostomum dorsal kinety pattern. The old, large, and difficult genus Oxytricha is briefly reviewed, mainly on the basis of the dorsal kinety pattern. Very likely, only species with the Oxytricha pattern belong to this genus. Oxytricha marcili and O. pseudofurcata, which have the Urosomoida kinety pattern (i.e. kinety 3 fragmentation lacking), are transferred to Urosomoida which is, inter alia, defined by a more or less distinctly reduced number of ventral and transverse cirri. Some other Oxytricha species with this kinety pattern (O. islandica, O. lanceolata, O. pseudosimilis, O. setigera) are not transferred to Urosomoida, but preliminarily classified as incertae sedis in Oxytricha, because they have the full set of 18 cirri. The available molecular data on O. lanceolata indicate that this type of 18-cirri hypotrichs likely needs a genus of its own because O. lanceolata does not cluster with O. granulifera, type of this genus. The marine Actinotricha saltans, classified for a very long time in Oxytricha, seems to be a non-dorsomarginalian hypotrich according to molecular data, justifying the reactivation of the old genus Actinotricha. Oxytricha shii has a multiple dorsal kinety 3 fragmentation, three dorsomarginal rows, and the undulating membranes arranged in the Cyrtohymena pattern, strongly indicating that it is a member of the subgenus Cyrtohymena (Cyrtohymenides). This brief review is a further step to unravel the complicated systematics of the old, but still little-known genus Oxytricha. The following new combinations are made in this paper: Cyrtohymena (Cyrtohymenides) shii (Shi et al., 1997) comb. nov.; Heterooxytricha szaboi (Wilbert and Song, 2005) comb. nov.; Heterooxytricha geleii (Wilbert, 1986) comb. nov.; Urosomoida marcili (Paiva and Silva-Neto, 2004) comb. nov.; Urosomoida pseudofurcata (Berger, 1999) comb. nov.
Jae-Ho Jung, Ye-Seul Baek, Sanghee Kim, Han-Gu Choi, Gi-Sik Min
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 289-300
https://doi.org/10.4467/16890027AP.11.026.0063In this study, a new marine urostylid ciliate, Metaurostylopsis antarctica nov. spec. collected from the Antarctic Ocean was investigated using morphological, morphometrical, and molecular methods. Metaurostylopsis antarctica nov. spec. is characterized as follows: slender to ellipsoid form in body shape; two types of cortical granules, ellipsoid large one (type I, yellow-green, 1.5 × 1 μm) in rows along dorsal kineties and cirri, circular small one (type II, colourless, 0.3 μm in diameter) scattered throughout whole body; 19–24 adoral membranelles, 4 frontal cirri, 2–5 frontoterminal cirri, 1 buccal and 2 transverse cirri; 3–5 midventral pairs, 10–15 cirri of midventral row; 1 right and 2 left marginal rows; 3 dorsal kineties; about 43 macronuclear nodules. This new species mainly differs from the congeners by the number of marginal rows (1 vs. 3 or more on right side; 2 vs. 3 or more on left side). In addition, proter’s oral primordium developed on the right side of the oral cavity (vs. in center of oral cavity), and the rightmost anlage splits into two parts, nam ely, the frontoterminal cirri and a transverse cirrus (vs. only frontoterminal cirri). Inter-specific dissimilarities of the SSU rRNA gene between the congeners range from 3.3 to 4.4%.
Xuming Pan, Chen Shao, Honggang Ma, Xinpeng Fan, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj, Xiaozhong Hu
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 301-310
https://doi.org/10.4467/16890027AP.11.027.0064The morphology and infraciliature of two marine scuticociliates, Pleuronema puytoraci Grolière and Detcheva, 1974, and Parauronema longum Song, 1995, collected from China, were investigated using live observation and protargol impregnation methods. Based on the data obtained for the China population, new information of the living morphology of Pleuronema puytoraci is documented and details of the complete infraciliature is available for the first time. The stomatogenesis of Parauronema longum is basically similar to that of its congeners and can be summarized as follows: membranelle 1, membranelle 2 and the scutica of the opisthe originate from the parental paroral membrane, whereas membranelle 3 of the opisthe develops from the parental scutica; the paroral membrane originates from the parental paroral membrane.
Karolina Lukášová, Jaroslav Holuša
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 311-318
https://doi.org/10.4467/16890027AP.11.028.0065Changes in Gregarina typographi Fuchs, 1915 (Eugregarinorida: Gregarinidae) infection levels were studied in a population of the bark beetle Ips typographus (L., 1758) (Coleoptera: Curculionidae), which lives in association with Norway spruce. Beetles were repeatedly collected from three logs of trap trees during 2009 and 2010 at one study site in the Czech Republic with a high level of G. typographi infection (seasonal mean of 15.7% in 2009 and 19.8% in 2010). Infection levels did not differ statistically between sexes, logs, and trap trees but did differ among sampling dates. During the beetle reproductive period, the infection levels nearly doubled in 2009 (from 10.7 to 19.8%) and more than tripled in 2010 (from 9.3 to 31.3%). We infer that the continuous increase in the G. typographi infection level within each of the two years resulted from transmission among beetles in nuptial chambers during the May–June reproductive and egg-laying period.
Tim Snelling, Eric Pinloche, Hilary J. Worgan, Jamie Newbold, Neil R. McEwan
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 319-326
https://doi.org/10.4467/16890027AP.11.029.0066Single cell morphotypes of the species Triadinium caudatum and Spirodinium equi, together with a representative of the genus Blepharocorys (Blepharocorys sp.) were used for phylogenetic analysis based on their 18S rRNA genes. Spirodinium equi clustered with sequences already described for the entodiniomorphs isolated from horses and the Blepharocorys sp. also grouped within the Entodiniomorphida clade, although both sequences were distinct from those described from rumen ciliates. Triadinium caudatum clustered within the Vestibuliferida, and most closely to that of Paraisotricha, only other member of this order which has been described in the horse. It was concluded that although members of the orders Entodiniomorphida and Vestibuliferida are present in the equine gut, and that they share an ancient linage with their rumen counterparts, they are ancestrally different groups.
Sónia Rocha, Graça Casal, Patrícia Matos, Edilson Rodrigues Matos, Mohamed A. Dkhil, Carlos Azevedo
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 327-338
https://doi.org/10.4467/16890027AP.11.030.0067A fish-infecting myxosporean was found in the urinary bladder of the teleostean Colomesus psittacus, collected from the Amazon River, Brazil. Specimens were sampled in three different periods: May and June, with water temperature ranging from 18–23ºC; August, with water temperature ranging from 24–28ºC; and November and December, with water temperature ranging from 29–32ºC. Upon observation, several fish displayed abnormal behaviour, consisting of erratic movements, and mortality was recorded among them. Necropsy of all sampled fishes revealed hypertrophy of the urinary bladder only among specimens previously displaying the irregular behaviour. Microscopic analysis of this organ confirmed the parasitic infection, resulting in the observation of spores floating free in the urine, and numerous plasmodia attached to the epithelium of the urinary bladder. Light and ultrastructural studies allowed recognition of the spores and plasmodia morphological characteristics. Coelozoic plasmodia were polysporic with varying organizational structure, according to the sampling period. Spores were equilaterally triangular with rounded ends in valvar view, measuring 8.8 ± 0.4 μm (n = 30) in length and 8.4 ± 0.5 μm (n = 30) in width, and displaying a ridge surface pattern. Two polar capsules were observed in the anterior end of the spores, measuring 3.1–3.2 μm in diameter. The spores were morphologically identified as belonging to the recently described genus Triangulamyxa. Further observation and comparison to the morphological features described for Triangulamyxa amazonica, the only other species within this genus, allowed us to conclude our parasite as a new species, herein named Triangulamyxa psittaca sp. nov. from the Amazon River, Brazil. Also, three different stages were distinguished in the plasmodium evolution, based on the observed morphological features at the three sampling periods. Fish sampled during May and June displayed small plasmodia (up to ~ 15–20 μm long), containing early stages of sporogenic development. Fish sampled during November and December presented larger plasmodia (up to ~ 850 μm long), which appeared flattened against and lining the urinary bladder epithelial cells and contained the later stages of sporogenic development, including some mature spores. Fish sampled during August presented plasmodia displaying intermediate morphological features between those observed in infected fish from the other sampling periods. Several immature and mature spores were among the different developmental stages. The parasite-host interface evolution is described throughout the different observed stages, with emphasis on the formation of septate junctions. Considering several previous reports, as well as the different environmental conditions during the sampling periods, the plasmodium development here described appears to be influenced by environmental factors, namely water temperature.
Toshimasa Kobayashi, Nobuyuki Nakano, Takaaki Muto, Yoshinari Endo
Acta Protozoologica, Volume 50, Issue 4, 2011, pp. 339-343
https://doi.org/10.4467/16890027AP.11.031.0068Suctorians of the genus Ephelota are stalked ciliates and ectocommensals of marine invertebrates and plants. Ephelota gigantea has long been known as a major nuisance to the cultured seaweed industries in the coastal area of northeastern Japan. However, little is known about its life history, so in situ growth experiments were performed in the vicinity of wakame (Undaria pinnatifida) long-line culture in Iwate Prefecture, and the development of swarmers was investigated in the laboratory. The stalk elongated first, followed by enlargement of body length and body width, with body width increasing linearly with time. Over 5–6 days, E. gigantea increased 4–5-fold by external budding. Such an experiment was carried out for the first time for E. gigantea and possibly for any Ephelota species. The information obtained is important not only in understanding the life history of this species but also for understanding the interactions with host organisms.
Publication date: 2011
Editor-in-Chief: Krzysztof Wiąckowski
Fernando Gómez, Luis López-Medina, David Moreira
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 141-153
https://doi.org/10.4467/16890027AP.11.024.0024Amphidiniopsis is one of the most specious genera of sand-dwelling dinoflagellates. However, its systematic position and the affinities to other genera remain unresolved. We obtained the first SSU rDNA sequences of two species of Amphidiniopsis, A. hirsuta and A. swedmarkii collected from the French coasts of the English Channel. In the corresponding SSU rDNA phylogeny, the sand-dwelling Amphidiniopsis spp., Thecadinium dragescoi, Herdmania litoralis and the planktonic Archaeperidinium (= Protoperidinium) minutum formed a strongly supported clade (100% bootstrap support), with a Scrippsiella-like species occupying a basal position. This clade branched close to families of Peridiniales such as Calciodinellaceae (Scripssiella), Podolampadaceae (Podolampas, Roscoffia), Heterocapsaceae (Heterocapsa) and other peridinioids. The members of the clade of Amphidiniopsis are placed in the family Amphidiniopsidaceae, within
the Peridiniales.
Jan Słodki, Krzysztof Piotr Jasik, Małgorzata Kępa, Danuta Idzik, Robert Dariusz Wojtyczka
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 155-16
https://doi.org/10.4467/16890027AP.11.017.0017The objective of this study is to draw attention to Apicomplexa-caused diseases transmitted by ticks. We present ultimate and intermediate hosts of Apicomplexa, including man, as well as vectors transmitting these unicellular Protista. We describe symptoms of Apicomplexa-caused diseases and contemporary methods of diagnostics and therapy. It is noteworthy that the ticks and tick-transmitted pathogenes are distinctly increasing their distribution ranges. Besides, it is important that the ticks are adapted to use many different hosts, including birds, which increases the ticks’ expansion abilities.
Yuhong Qin, Zijian Qiu, Chen Shao, Alan Warren, Zhuo Shen
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 163-174
https://doi.org/10.4467/16890027AP.11.018.0018The morphology and morphogenesis of the hypotrich ciliate Urosoma macrostyla (Wrześniowski, 1866) Berger, 1999, collected from a puddle in Harbin, China, were investigated using live observation and protargol impregnation. Based on previous and present studies, an improved diagnosis of U. macrostyla is supplied. It differs from its congeners mainly by the body shape, no cortical granules and number of macronuclear nodules. The ontogenesis of U. macrostyla is typical for species with such a somatic ciliary pattern: the oral primordium develops hypoapokinetally and FVT-anlagen develop in 5-streaks and primary mode. However, a unique characteristic in morphogenetic process is reported: anlagen for both the left and right marginal cirri occur de novo to the right of the parental structure which has never been seen in other oxytrichids. This characteristic was considered an apomorphy (Berger 1999). This indicates that U. macrostyla possibly has a high phylogenetic position within the genus Urosoma, or perhaps it represents a distinct subgenus.
Wei He, Chen Shao, Xinbai Shi, Helmut Berger
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 175-203
https://doi.org/10.4467/16890027AP.11.019.0019In 1988, we found a large (250–400 × 80–150 μm in protargol preparations) Uroleptus-like hypotrich in a freshwater pond in Harbin, China. We studied the morphology of non-dividers and the cell division using protargol impregnation. Since we disregarded live observations and due to the lack of a modern revision of the uroleptids, a final identification was not possible. A detailed comparison with the most similar limnetic Uroleptus-like hypotrichs and with Rigidothrix goiseri revealed that the Chinese population is very likely identical with Uroleptus magnificus [basionym Holosticha (Paruroleptus) magnificus Kahl, 1932], a very rare species possibly confined to limnetic, stagnant water bodies of the holarctic region. Besides the large size, main features of U. cf. magnificus are: (i) about 80 adoral membranelles; (ii) three or four inconspicuous transverse cirri; (iii) 5–8 dorsomarginal kineties; (iv) the oral primordium originates de novo left of the postoral midventral cirri; (v) the frontal-ventral-transverse cirri anlagen of the proter and the opisthe originate via primary primordia; (vi) the left frontal cirrus of the proter originates from the middle portion of the disorganizing parental paroral; (vii) the parental endoral becomes the undulating membrane anlage for the proter; and (viii) the frontoterminal cirri originate in the plesiomorphic manner, that is, from the rearmost anlage. A compilation reveals that 59 species, subspecies, etc. have been described in or assigned to Uroleptus and Paruroleptus, but only about 50% of them seem to be true uroleptids. Many species of this predominantly limnetic group are little known.
Yuan Xu, Anton Esaulov, Xiaofeng Lin, Yuri A. Mazei, Xiaozhong Hu, Khaled A. S. Al-Rasheid, Alan Warren
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 205-218
https://doi.org/10.4467/16890027AP.11.020.0020The morphology and infraciliature of five trachelocercid ciliates: Tracheloraphis huangi spec. nov., T. colubis (Kahl, 1933) comb. nov., T. phoenicopterus (Cohn, 1866) Dragesco, 1960, T. oligostriata (Raikov, 1962) Foissner and Dragesco, 1996 and Trachelocerca incaudata Kahl, 1933, isolated from the intertidal zone of a beach at Qingdao, China, were studied in live and protargol impregnated specimens. Tracheloraphis huangi spec. nov. was distinguished from its congeners mainly by its single nuclear group composed of 25–30 round macronuclei and 29–37 somatic kineties. The poorly known T. colubis is redescribed including for the first time information on its infraciliature. An improved diagnosis is also provided. In light of its infraciliature, T. colubis is transferred to Tracheloraphis from the genus Trachelocerca. Additional data on other three species is supplied based on the Qingdao populations.
Xinpeng Fan, Xiaofeng Lin, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj, Alan Warren, Weibo Song
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 219-234
https://doi.org/10.4467/16890027AP.11.021.0021Eight marine scuticociliates, Pseudoplatynematum denticulatum (Kahl, 1933) nov. comb., Protocyclidium sinica nov. spec., Histiobalantium marinum Kahl, 1933, Porpostoma notata Möbius, 1888, Philaster hiatti Thompson, 1969, Parauronema longum Song, 1995, Uronemella parafilificum Gong et al., 2007, and Paranophrys magna Borror, 1972, collected from Chinese coastal waters, were investigated using live observations and silver impregnation methods. Investigations of a Chinese population of Platynematum denticulatum (Kahl, 1933) reveal that it has a highly strengthened pellicle and distinct spines and thus corresponds well with the definition of Pseudoplatynematum Bock, 1952. A new combination, Pseudoplatynematum denticulatum (Kahl, 1933) nov. comb., is therefore proposed and an improved species diagnosis is supplied. Protocyclidium sinica nov. spec. is characterized by: small body size with buccal field approximately 60% of body length; extrusomes present; 13 or 14 somatic kineties; somatic kinety 1 comprising approximately 24 densely arranged kinetids; somatic kinety n shortened posteriorly; single macronucleus. Additional information is documented on the morphology of six other species of scuticociliates based on the China populations.
Madlen Haentzsch, Detlef Bernhard, Thomas U. Berendonk, Ewa Przyboś, Martin Schlegel
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 235-238
https://doi.org/10.4467/16890027AP.11.022.0022The representatives of the genus Paramecium are well-studied ciliates and can be used in water quality assessment and the determinations of saprobic levels. For these applications, a clear and unambiguous identification of ciliate assemblages is essential, which is typically based on morphological characters requiring a sound taxonomic knowledge and experience in species determination including microscopic identification of both living and stained specimens. Therefore, we developed and applied specific PCR primers for the detection of species belonging to the genus Paramecium and the Paramecium aurelia complex. These primers were successfully tested with different Paramecium species including representatives of the P. aurelia complex as well as closely related species like Frontonia sp. and Tetrahymena sp. in both experimental and environmental samples. These primers can be used in a simultaneous approach achieving fast and reliable results with regard to determination of ciliate community and water assessment.
Alexander Kudryavtsev, Jan Pawlowski, Klaus Hausmann
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 239-253
https://doi.org/10.4467/16890027AP.11.023.0023A strain of marine amoeba has been isolated and studied from the bottom sediments of the Great Meteor Seamount (Atlantic Ocean, 29°36.29′N; 28°59.12′W; 267.4 m deep). This amoeba has a typical dactylopodiid morphotype, a coat of delicate, boat-shaped scales, and a Perkinsela-like organism (PLO), an obligatory, deeply-specialized kinetoplastid symbiont near the nucleus. These characters allow us to include this species into the genus Paramoeba. However, it differs from its only described species, P. eilhardi, in the structure of scales. P. atlantica n. sp. is established therefore to accommodate the studied strain. SSU rRNA gene sequence analysis suggests that P. atlantica belongs to the Dactylopodida, and is sister to a monophyletic clade of P. eilhardi and all Neoparamoeba spp., branching separately from P. eilhardi. Therefore, the genera Paramoeba and Neoparamoeba, currently defined based on the cell surface ultrastructure, might be paraphyletic and probably should be synonymized, as further evidence is accumulated. Based on the data available we emend the families Vexilliferidae and Paramoebidae to make them more consistent with the current phylogenetic schemes.
Fernando Gómez, Luis López-Medina, David Moreira
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 141-153
https://doi.org/10.4467/16890027AP.11.024.0024Amphidiniopsis is one of the most specious genera of sand-dwelling dinoflagellates. However, its systematic position and the affinities to other genera remain unresolved. We obtained the first SSU rDNA sequences of two species of Amphidiniopsis, A. hirsuta and A. swedmarkii collected from the French coasts of the English Channel. In the corresponding SSU rDNA phylogeny, the sand-dwelling Amphidiniopsis spp., Thecadinium dragescoi, Herdmania litoralis and the planktonic Archaeperidinium (= Protoperidinium) minutum formed a strongly supported clade (100% bootstrap support), with a Scrippsiella-like species occupying a basal position. This clade branched close to families of Peridiniales such as Calciodinellaceae (Scripssiella), Podolampadaceae (Podolampas, Roscoffia), Heterocapsaceae (Heterocapsa) and other peridinioids. The members of the clade of Amphidiniopsis are placed in the family Amphidiniopsidaceae, within
the Peridiniales.
Jan Słodki, Krzysztof Piotr Jasik, Małgorzata Kępa, Danuta Idzik, Robert Dariusz Wojtyczka
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 155-16
https://doi.org/10.4467/16890027AP.11.017.0017The objective of this study is to draw attention to Apicomplexa-caused diseases transmitted by ticks. We present ultimate and intermediate hosts of Apicomplexa, including man, as well as vectors transmitting these unicellular Protista. We describe symptoms of Apicomplexa-caused diseases and contemporary methods of diagnostics and therapy. It is noteworthy that the ticks and tick-transmitted pathogenes are distinctly increasing their distribution ranges. Besides, it is important that the ticks are adapted to use many different hosts, including birds, which increases the ticks’ expansion abilities.
Yuhong Qin, Zijian Qiu, Chen Shao, Alan Warren, Zhuo Shen
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 163-174
https://doi.org/10.4467/16890027AP.11.018.0018The morphology and morphogenesis of the hypotrich ciliate Urosoma macrostyla (Wrześniowski, 1866) Berger, 1999, collected from a puddle in Harbin, China, were investigated using live observation and protargol impregnation. Based on previous and present studies, an improved diagnosis of U. macrostyla is supplied. It differs from its congeners mainly by the body shape, no cortical granules and number of macronuclear nodules. The ontogenesis of U. macrostyla is typical for species with such a somatic ciliary pattern: the oral primordium develops hypoapokinetally and FVT-anlagen develop in 5-streaks and primary mode. However, a unique characteristic in morphogenetic process is reported: anlagen for both the left and right marginal cirri occur de novo to the right of the parental structure which has never been seen in other oxytrichids. This characteristic was considered an apomorphy (Berger 1999). This indicates that U. macrostyla possibly has a high phylogenetic position within the genus Urosoma, or perhaps it represents a distinct subgenus.
Wei He, Chen Shao, Xinbai Shi, Helmut Berger
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 175-203
https://doi.org/10.4467/16890027AP.11.019.0019In 1988, we found a large (250–400 × 80–150 μm in protargol preparations) Uroleptus-like hypotrich in a freshwater pond in Harbin, China. We studied the morphology of non-dividers and the cell division using protargol impregnation. Since we disregarded live observations and due to the lack of a modern revision of the uroleptids, a final identification was not possible. A detailed comparison with the most similar limnetic Uroleptus-like hypotrichs and with Rigidothrix goiseri revealed that the Chinese population is very likely identical with Uroleptus magnificus [basionym Holosticha (Paruroleptus) magnificus Kahl, 1932], a very rare species possibly confined to limnetic, stagnant water bodies of the holarctic region. Besides the large size, main features of U. cf. magnificus are: (i) about 80 adoral membranelles; (ii) three or four inconspicuous transverse cirri; (iii) 5–8 dorsomarginal kineties; (iv) the oral primordium originates de novo left of the postoral midventral cirri; (v) the frontal-ventral-transverse cirri anlagen of the proter and the opisthe originate via primary primordia; (vi) the left frontal cirrus of the proter originates from the middle portion of the disorganizing parental paroral; (vii) the parental endoral becomes the undulating membrane anlage for the proter; and (viii) the frontoterminal cirri originate in the plesiomorphic manner, that is, from the rearmost anlage. A compilation reveals that 59 species, subspecies, etc. have been described in or assigned to Uroleptus and Paruroleptus, but only about 50% of them seem to be true uroleptids. Many species of this predominantly limnetic group are little known.
Yuan Xu, Anton Esaulov, Xiaofeng Lin, Yuri A. Mazei, Xiaozhong Hu, Khaled A. S. Al-Rasheid, Alan Warren
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 205-218
https://doi.org/10.4467/16890027AP.11.020.0020The morphology and infraciliature of five trachelocercid ciliates: Tracheloraphis huangi spec. nov., T. colubis (Kahl, 1933) comb. nov., T. phoenicopterus (Cohn, 1866) Dragesco, 1960, T. oligostriata (Raikov, 1962) Foissner and Dragesco, 1996 and Trachelocerca incaudata Kahl, 1933, isolated from the intertidal zone of a beach at Qingdao, China, were studied in live and protargol impregnated specimens. Tracheloraphis huangi spec. nov. was distinguished from its congeners mainly by its single nuclear group composed of 25–30 round macronuclei and 29–37 somatic kineties. The poorly known T. colubis is redescribed including for the first time information on its infraciliature. An improved diagnosis is also provided. In light of its infraciliature, T. colubis is transferred to Tracheloraphis from the genus Trachelocerca. Additional data on other three species is supplied based on the Qingdao populations.
Xinpeng Fan, Xiaofeng Lin, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj, Alan Warren, Weibo Song
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 219-234
https://doi.org/10.4467/16890027AP.11.021.0021Eight marine scuticociliates, Pseudoplatynematum denticulatum (Kahl, 1933) nov. comb., Protocyclidium sinica nov. spec., Histiobalantium marinum Kahl, 1933, Porpostoma notata Möbius, 1888, Philaster hiatti Thompson, 1969, Parauronema longum Song, 1995, Uronemella parafilificum Gong et al., 2007, and Paranophrys magna Borror, 1972, collected from Chinese coastal waters, were investigated using live observations and silver impregnation methods. Investigations of a Chinese population of Platynematum denticulatum (Kahl, 1933) reveal that it has a highly strengthened pellicle and distinct spines and thus corresponds well with the definition of Pseudoplatynematum Bock, 1952. A new combination, Pseudoplatynematum denticulatum (Kahl, 1933) nov. comb., is therefore proposed and an improved species diagnosis is supplied. Protocyclidium sinica nov. spec. is characterized by: small body size with buccal field approximately 60% of body length; extrusomes present; 13 or 14 somatic kineties; somatic kinety 1 comprising approximately 24 densely arranged kinetids; somatic kinety n shortened posteriorly; single macronucleus. Additional information is documented on the morphology of six other species of scuticociliates based on the China populations.
Madlen Haentzsch, Detlef Bernhard, Thomas U. Berendonk, Ewa Przyboś, Martin Schlegel
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 235-238
https://doi.org/10.4467/16890027AP.11.022.0022The representatives of the genus Paramecium are well-studied ciliates and can be used in water quality assessment and the determinations of saprobic levels. For these applications, a clear and unambiguous identification of ciliate assemblages is essential, which is typically based on morphological characters requiring a sound taxonomic knowledge and experience in species determination including microscopic identification of both living and stained specimens. Therefore, we developed and applied specific PCR primers for the detection of species belonging to the genus Paramecium and the Paramecium aurelia complex. These primers were successfully tested with different Paramecium species including representatives of the P. aurelia complex as well as closely related species like Frontonia sp. and Tetrahymena sp. in both experimental and environmental samples. These primers can be used in a simultaneous approach achieving fast and reliable results with regard to determination of ciliate community and water assessment.
Alexander Kudryavtsev, Jan Pawlowski, Klaus Hausmann
Acta Protozoologica, Volume 50, Issue 3, 2011, pp. 239-253
https://doi.org/10.4467/16890027AP.11.023.0023A strain of marine amoeba has been isolated and studied from the bottom sediments of the Great Meteor Seamount (Atlantic Ocean, 29°36.29′N; 28°59.12′W; 267.4 m deep). This amoeba has a typical dactylopodiid morphotype, a coat of delicate, boat-shaped scales, and a Perkinsela-like organism (PLO), an obligatory, deeply-specialized kinetoplastid symbiont near the nucleus. These characters allow us to include this species into the genus Paramoeba. However, it differs from its only described species, P. eilhardi, in the structure of scales. P. atlantica n. sp. is established therefore to accommodate the studied strain. SSU rRNA gene sequence analysis suggests that P. atlantica belongs to the Dactylopodida, and is sister to a monophyletic clade of P. eilhardi and all Neoparamoeba spp., branching separately from P. eilhardi. Therefore, the genera Paramoeba and Neoparamoeba, currently defined based on the cell surface ultrastructure, might be paraphyletic and probably should be synonymized, as further evidence is accumulated. Based on the data available we emend the families Vexilliferidae and Paramoebidae to make them more consistent with the current phylogenetic schemes.
Publication date: 2011
Editor-in-Chief: Krzysztof Wiąckowski
Y Sogame, Hiroka Asami, Eiji Kinoshita, Tatsuomi Matsuoka
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 71-79
https://doi.org/10.4467/16890027AP.11.009.0009It has been suggested that encystment of Colpoda cucullus is mediated by intracellular Ca2+-activated signaling pathways involving an increase in the cAMP concentration. In the present study, cAMP enzyme immunoassay (EIA) and chemiluminescence detection for phosphorylated proteins using anti-phosphoserine antibody, anti-phosphothreonine antibody and biotinylated phosphate-binding tag molecules (Phos-tag) showed that the intracellular cAMP concentration in Colpoda cells was raised and the phosphorylation level of serine/threonine residues was elevated in many proteins prior to the cyst formation. Such encystment induction and protein phosphorylation were suppressed by the addition of an intracellular Ca2+ chelating reagent (BAPTA-AM) or the encystment inhibitor, chlorophyllin in all or most of these proteins, respectively. The phosphorylation level of some proteins was slightly elevated by the addition of IBMX, which tended to promote encystment induction, and tended to be slightly suppressed by the addition of H-89 (PKA inhibitor), which also suppressed encystment induction. These results suggest that Ca2+-activated signaling pathway involving cAMP/PKA-dependent protein phosphorylation may be responsible for the encystment induction of C. cucullus.
Arturo González-Robles, A. R. Cristóbal-Ramos, Monica González-Lázaro, M. Omaña-Molina, Adolfo Martínez-Palomo
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 81-87
https://doi.org/10.4467/16890027AP.11.010.0010Morphological differences in cap formation were found when trophozoites of different free-living amoebae were treated with the lectin Concanavalin A, which resulted in a rapid redistribution of certain surface components to form small clusters and membrane-folded structures of diverse sizes. Acanthamoeba castellanii, Acanthamoba polyphaga and Naegleria lovaniensis exhibited characteristic caps, however, in A. castellanii this structure was larger and included several folds of the plasma membrane; furthermore, some of these caps had vacuoles containing a fi bro granular content. In contrast, the caps formed by A. polyphaga and N. lovaniensis lacked vacuoles. Regarding Naegleria fowleri, the trophozoites did not produce a defi ned cap, and only small patches of lectin-bound surface receptor complexes were observed at one pole of the cell body. In the free-living amoebae studied, it was not possible to correlate the shape and size of cap with pathogenicity.
Atef Omar, Wilhelm Foissner
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 89-103
https://doi.org/10.4467/16890027AP.11.011.0011Using standard morphological methods, we describe two new Leptopharynx species, each discovered in a specific biogeographic region and habitat. Leptopharynx bromeliophilus nov. spec., a minute species (25 × 20 μm) discovered in tanks of bromeliads from Jamaica, is small-mouthed and has a slightly concave preoral region, an average of 27 basal bodies in kinety 4, and a total of 142 basal bodies on average. Leptopharynx australiensis nov. spec., a comparatively large species (40 × 25 μm) discovered in jungle soil of Australia, is large-mouthed and has a distinctly oblique preoral region, widely spaced kinetids in kinety 1, a total of 184 basal bodies on average, and the oral primordium is inside of a cortical fold thus appearing right of the posterior end of kinety 1. Four new features are recognized for distinguishing Leptopharynx species: (1) to have a monomorphic (producing either small- or large-mouthed cells) or polymorphic (producing microstomes and macrostomes) life cycle; (2) the spacing of the kinetids in kinety 1 as either ordinary or wide; (3) the shape (flat or concave) and angle (≤ 15° slightly oblique, ≥ 40° distinctly oblique) of the preoral region; and (4) the total number of basal bodies, which has proven statistically.
Xiangrui Chen, Jun Gong, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj, Weibo Song
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 105-119
https://doi.org/10.4467/16890027AP.11.012.0012The morphology and infraciliature of three marine cyrtophorid ciliates, Dysteria lanceolata Claparède and Lachmann, 1859, Lynchella nordica Jankowski, 1968 and Chlamydonyx paucidentatus Deroux, 1976, collected from the coastal waters of Qingdao, China, were investigated using live observations and the protargol impregnation method. D. lanceolata was oval in body outline, about 65 × 45 μm in vivo, with a subcaudally positioned podite, six to seven right kineties, two or three frontoventral kineties, and two ventral contractile vacuoles. The improved diagnosis for L. nordica and a key to all known Lynchella species are supplied. The rediscovery of C. paucidentatus enables us to accept its taxonomic identification (e.g., separation from a morphologically similar species Trochilioides recta). The genus Trochilioides Deroux, nov. gen., which was a nomen nudum according to ICZN (1999), is re-established.
Richard E. Fallon, Ueli Merz, Ros A. Lister, Andrew R. Wallace, Simon P. Hayes
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 121-132
https://doi.org/10.4467/16890027AP.11.013.0013Plasmodiophorid sporosori (aggregations of resting spores) reach their most complex form in Spongospora subterranea f. sp. subterranea, the biotrophic plant pathogen which causes the economically important disease powdery scab of potato (Solanum tuberosum). Resting spores are the perennation life cycle stage of plasmodiophorids, allowing them to survive for long periods and infect subsequent host generations. Light microscopy was used to measure resting spores and sporosori of Sp. subterranea, and enumerate resting spores in individual sporosori. Mean resting spore diameters differed for two sporosorus collections, being 4.0 μm (from New Zealand) and 4.3 μm (from Switzerland). Counts of resting spores in 4 μm thick serial sections of sporosori from one collection gave a mean of 667 (range 155 to 1,526) resting spores per sporosorus. Number of resting spores per sporosorus was closely related to sporosorus volume, and could be accurately estimated using the formula; number of resting spores = 0.0081 × sporosorus volume (assuming sporosori to be spheroids). Using this formula, mean numbers of resting spores in sporosori from 37 Sp. subterranea collections from field-grown potato tubers from 13 countries were determined to range from 199 to 713. Differences in numbers of resting spores between the collections were statistically significant (P < 0.05), and independent of country or host cultivar of origin, indicating that enumeration should be carried out for individual sporosorus collections to accurately quantify inoculum. Morphology, using scanning electron microscopy, also showed that between 2 and 51% (average 20%) of resting spores released zoospores after exposure to roots of host plants. The formula for resting spore enumeration validated in this study can be used to standardise Sp. subterranea resting spore inoculum for plant pathology studies, and possibly to assist determination of soil inoculum potential for disease risk evaluations.
Timothée Vergne, Ketsarin Kamyinkird, Marc Desquesnes, Sathaporn Jittapalapong
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 133-136
https://doi.org/10.4467/16890027AP.11.014.0014Trypanosoma evansi is a blood parasite principally transmitted by mechanical vectors (tabanids and stable flies) in large animals such as livestock. However, in other types of hosts, such as carnivores and rodents, oral transmission may be more important. In this experiment, attempts were made to infect rats and mice by the peroral route using infected blood, and ticks engorged on infected rats, in order to evaluate the potential role of ticks as passive vectors of trypanosomes. A strain of Trypanosoma evansi isolated from a cow in Thailand was grown in a rat and blood was collected at the peak of parasitaemia. In the first experiment, 5 rats and 5 mice were fed respectively with 1 ml and 0.5 ml of blood containing 107 Trypanosoma evansi/ml. In the second experiment, adult ticks belonging to the species Rhipicephalus sanguineus, which had fed on parasitaemic rats, were given as food to 3 healthy rats. For both experiments, the presence of parasites in the blood of the rats and mice was checked daily for 10 days, then every 2 days for the following 20 days. Within an average of 4.5 days post blood ingestion (from 4 to 5), 80% (CI95% 29–99) of the rats exhibited parasites by direct microscopic examination of the blood. Similarly, with an average of 4.7 days post ingestion (from 4 to 6), 60% (CI95% 15–95) of the mice exhibited blood parasites. After tick ingestion, no parasites were found in the blood of the rats fed with infected engorged ticks. Consequently, in this experiment, as in others, rats and mice appeared to be receptive by the oral route, but the possible role of ticks as a passive vector could not be demonstrated. Other models could be explored, involving the cattle tick (Rhipicephalus (Boophilus) microplus), to investigate the link from large to small animals.
Cleide D. Coelko, Bruno P. Berto, Daniel M. Neves, Vinícius M. de Oliveira, Walter Flausino, Carlos W. G. Lopes
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 137-140
https://doi.org/10.4467/16890027AP.11.015.0015This current study reports a new isosporoid (Apicomplexa: Eimeriidae) species parasitizing tropical mockingbirds Mimus gilvus recovered from illegal trade in Brazil. Isospora mimusi n. sp. oocysts are spherical to sub-spherical, 20.6 × 19.6 μm, with smooth, bilayered wall, ~1.2 μm. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are ovoidal, 13.4 × 9.8 μm. Stieda and substieda bodies are present. Sporocyst residuum composed of diffuse granules of various sizes, sporozoites have one refractile body.
Biplob Kr. Modak, Saugata Basu, Durga P. Haldar
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 141-153
https://doi.org/10.4467/16890027AP.11.016.0016Two new species of Phleobum (Apicomplexa: Eugregarinida: Hirmocystidae) are described from adult grasshoppers in Kalyani, India. Phleobum globuloepimeritum n. sp. is described from Oxya hyla hyla (Insecta: Orthoptera: Acrididae) and Phleobum elliptica n. sp. from Atractomorpha crenulata (Insecta: Orthoptera: Pyrgomorphidae). In P. globuloepimeritum, the trophozoites are solitary, orangecoloured, have a maximum length of 352 μm with a hyaline globular epimerite and the protomerite in satellite is characteristically flanged. The gametocyst is orange, orbicular, averaging 300 × 250 μm in size, dehiscing through a pore after 50 h. The oocysts are uniformly smooth, ellipsoidal, measuring 9 × 5 μm. In P. elliptica trophozoites are also solitary, orange-coloured, having a maximum length of 157 μm with triangular epimerites. The protomerite flange is typically a bowel-shaped collar. The gametocyst is yellow-orange, ellipsoidal, averaging 240 × 165 μm and dehisces through a pore after 72 h, releasing smooth-walled, ellipsoidal, uniformly shaped oocysts measuring 5 × 3 μm. The two new species share traits, which define the genus such as: gamonts in association, satellites with characteristic flange and gametocysts dehiscence through a single pore. The epimerite of P. globuloepimeritum is hyaline and globular, which is unique among members of the genus. The gametocyst of P. elliptica is notably ellipsoidal. Basing on observation on all the described and present two species, generic characters of the genus Phleobum have been redefined. The genus is also transferred from the family Didymophyidae to the family Hirmocystidae as the gametocysts in all the species of Phleobum dehisce through a pore.
Y Sogame, Hiroka Asami, Eiji Kinoshita, Tatsuomi Matsuoka
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 71-79
https://doi.org/10.4467/16890027AP.11.009.0009It has been suggested that encystment of Colpoda cucullus is mediated by intracellular Ca2+-activated signaling pathways involving an increase in the cAMP concentration. In the present study, cAMP enzyme immunoassay (EIA) and chemiluminescence detection for phosphorylated proteins using anti-phosphoserine antibody, anti-phosphothreonine antibody and biotinylated phosphate-binding tag molecules (Phos-tag) showed that the intracellular cAMP concentration in Colpoda cells was raised and the phosphorylation level of serine/threonine residues was elevated in many proteins prior to the cyst formation. Such encystment induction and protein phosphorylation were suppressed by the addition of an intracellular Ca2+ chelating reagent (BAPTA-AM) or the encystment inhibitor, chlorophyllin in all or most of these proteins, respectively. The phosphorylation level of some proteins was slightly elevated by the addition of IBMX, which tended to promote encystment induction, and tended to be slightly suppressed by the addition of H-89 (PKA inhibitor), which also suppressed encystment induction. These results suggest that Ca2+-activated signaling pathway involving cAMP/PKA-dependent protein phosphorylation may be responsible for the encystment induction of C. cucullus.
Arturo González-Robles, A. R. Cristóbal-Ramos, Monica González-Lázaro, M. Omaña-Molina, Adolfo Martínez-Palomo
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 81-87
https://doi.org/10.4467/16890027AP.11.010.0010Morphological differences in cap formation were found when trophozoites of different free-living amoebae were treated with the lectin Concanavalin A, which resulted in a rapid redistribution of certain surface components to form small clusters and membrane-folded structures of diverse sizes. Acanthamoeba castellanii, Acanthamoba polyphaga and Naegleria lovaniensis exhibited characteristic caps, however, in A. castellanii this structure was larger and included several folds of the plasma membrane; furthermore, some of these caps had vacuoles containing a fi bro granular content. In contrast, the caps formed by A. polyphaga and N. lovaniensis lacked vacuoles. Regarding Naegleria fowleri, the trophozoites did not produce a defi ned cap, and only small patches of lectin-bound surface receptor complexes were observed at one pole of the cell body. In the free-living amoebae studied, it was not possible to correlate the shape and size of cap with pathogenicity.
Atef Omar, Wilhelm Foissner
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 89-103
https://doi.org/10.4467/16890027AP.11.011.0011Using standard morphological methods, we describe two new Leptopharynx species, each discovered in a specific biogeographic region and habitat. Leptopharynx bromeliophilus nov. spec., a minute species (25 × 20 μm) discovered in tanks of bromeliads from Jamaica, is small-mouthed and has a slightly concave preoral region, an average of 27 basal bodies in kinety 4, and a total of 142 basal bodies on average. Leptopharynx australiensis nov. spec., a comparatively large species (40 × 25 μm) discovered in jungle soil of Australia, is large-mouthed and has a distinctly oblique preoral region, widely spaced kinetids in kinety 1, a total of 184 basal bodies on average, and the oral primordium is inside of a cortical fold thus appearing right of the posterior end of kinety 1. Four new features are recognized for distinguishing Leptopharynx species: (1) to have a monomorphic (producing either small- or large-mouthed cells) or polymorphic (producing microstomes and macrostomes) life cycle; (2) the spacing of the kinetids in kinety 1 as either ordinary or wide; (3) the shape (flat or concave) and angle (≤ 15° slightly oblique, ≥ 40° distinctly oblique) of the preoral region; and (4) the total number of basal bodies, which has proven statistically.
Xiangrui Chen, Jun Gong, Khaled A. S. Al-Rasheid, Saleh A. Al-Farraj, Weibo Song
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 105-119
https://doi.org/10.4467/16890027AP.11.012.0012The morphology and infraciliature of three marine cyrtophorid ciliates, Dysteria lanceolata Claparède and Lachmann, 1859, Lynchella nordica Jankowski, 1968 and Chlamydonyx paucidentatus Deroux, 1976, collected from the coastal waters of Qingdao, China, were investigated using live observations and the protargol impregnation method. D. lanceolata was oval in body outline, about 65 × 45 μm in vivo, with a subcaudally positioned podite, six to seven right kineties, two or three frontoventral kineties, and two ventral contractile vacuoles. The improved diagnosis for L. nordica and a key to all known Lynchella species are supplied. The rediscovery of C. paucidentatus enables us to accept its taxonomic identification (e.g., separation from a morphologically similar species Trochilioides recta). The genus Trochilioides Deroux, nov. gen., which was a nomen nudum according to ICZN (1999), is re-established.
Richard E. Fallon, Ueli Merz, Ros A. Lister, Andrew R. Wallace, Simon P. Hayes
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 121-132
https://doi.org/10.4467/16890027AP.11.013.0013Plasmodiophorid sporosori (aggregations of resting spores) reach their most complex form in Spongospora subterranea f. sp. subterranea, the biotrophic plant pathogen which causes the economically important disease powdery scab of potato (Solanum tuberosum). Resting spores are the perennation life cycle stage of plasmodiophorids, allowing them to survive for long periods and infect subsequent host generations. Light microscopy was used to measure resting spores and sporosori of Sp. subterranea, and enumerate resting spores in individual sporosori. Mean resting spore diameters differed for two sporosorus collections, being 4.0 μm (from New Zealand) and 4.3 μm (from Switzerland). Counts of resting spores in 4 μm thick serial sections of sporosori from one collection gave a mean of 667 (range 155 to 1,526) resting spores per sporosorus. Number of resting spores per sporosorus was closely related to sporosorus volume, and could be accurately estimated using the formula; number of resting spores = 0.0081 × sporosorus volume (assuming sporosori to be spheroids). Using this formula, mean numbers of resting spores in sporosori from 37 Sp. subterranea collections from field-grown potato tubers from 13 countries were determined to range from 199 to 713. Differences in numbers of resting spores between the collections were statistically significant (P < 0.05), and independent of country or host cultivar of origin, indicating that enumeration should be carried out for individual sporosorus collections to accurately quantify inoculum. Morphology, using scanning electron microscopy, also showed that between 2 and 51% (average 20%) of resting spores released zoospores after exposure to roots of host plants. The formula for resting spore enumeration validated in this study can be used to standardise Sp. subterranea resting spore inoculum for plant pathology studies, and possibly to assist determination of soil inoculum potential for disease risk evaluations.
Timothée Vergne, Ketsarin Kamyinkird, Marc Desquesnes, Sathaporn Jittapalapong
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 133-136
https://doi.org/10.4467/16890027AP.11.014.0014Trypanosoma evansi is a blood parasite principally transmitted by mechanical vectors (tabanids and stable flies) in large animals such as livestock. However, in other types of hosts, such as carnivores and rodents, oral transmission may be more important. In this experiment, attempts were made to infect rats and mice by the peroral route using infected blood, and ticks engorged on infected rats, in order to evaluate the potential role of ticks as passive vectors of trypanosomes. A strain of Trypanosoma evansi isolated from a cow in Thailand was grown in a rat and blood was collected at the peak of parasitaemia. In the first experiment, 5 rats and 5 mice were fed respectively with 1 ml and 0.5 ml of blood containing 107 Trypanosoma evansi/ml. In the second experiment, adult ticks belonging to the species Rhipicephalus sanguineus, which had fed on parasitaemic rats, were given as food to 3 healthy rats. For both experiments, the presence of parasites in the blood of the rats and mice was checked daily for 10 days, then every 2 days for the following 20 days. Within an average of 4.5 days post blood ingestion (from 4 to 5), 80% (CI95% 29–99) of the rats exhibited parasites by direct microscopic examination of the blood. Similarly, with an average of 4.7 days post ingestion (from 4 to 6), 60% (CI95% 15–95) of the mice exhibited blood parasites. After tick ingestion, no parasites were found in the blood of the rats fed with infected engorged ticks. Consequently, in this experiment, as in others, rats and mice appeared to be receptive by the oral route, but the possible role of ticks as a passive vector could not be demonstrated. Other models could be explored, involving the cattle tick (Rhipicephalus (Boophilus) microplus), to investigate the link from large to small animals.
Cleide D. Coelko, Bruno P. Berto, Daniel M. Neves, Vinícius M. de Oliveira, Walter Flausino, Carlos W. G. Lopes
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 137-140
https://doi.org/10.4467/16890027AP.11.015.0015This current study reports a new isosporoid (Apicomplexa: Eimeriidae) species parasitizing tropical mockingbirds Mimus gilvus recovered from illegal trade in Brazil. Isospora mimusi n. sp. oocysts are spherical to sub-spherical, 20.6 × 19.6 μm, with smooth, bilayered wall, ~1.2 μm. Micropyle, oocyst residuum and polar granule are absent. Sporocysts are ovoidal, 13.4 × 9.8 μm. Stieda and substieda bodies are present. Sporocyst residuum composed of diffuse granules of various sizes, sporozoites have one refractile body.
Biplob Kr. Modak, Saugata Basu, Durga P. Haldar
Acta Protozoologica, Volume 50, Issue 2, 2011, pp. 141-153
https://doi.org/10.4467/16890027AP.11.016.0016Two new species of Phleobum (Apicomplexa: Eugregarinida: Hirmocystidae) are described from adult grasshoppers in Kalyani, India. Phleobum globuloepimeritum n. sp. is described from Oxya hyla hyla (Insecta: Orthoptera: Acrididae) and Phleobum elliptica n. sp. from Atractomorpha crenulata (Insecta: Orthoptera: Pyrgomorphidae). In P. globuloepimeritum, the trophozoites are solitary, orangecoloured, have a maximum length of 352 μm with a hyaline globular epimerite and the protomerite in satellite is characteristically flanged. The gametocyst is orange, orbicular, averaging 300 × 250 μm in size, dehiscing through a pore after 50 h. The oocysts are uniformly smooth, ellipsoidal, measuring 9 × 5 μm. In P. elliptica trophozoites are also solitary, orange-coloured, having a maximum length of 157 μm with triangular epimerites. The protomerite flange is typically a bowel-shaped collar. The gametocyst is yellow-orange, ellipsoidal, averaging 240 × 165 μm and dehisces through a pore after 72 h, releasing smooth-walled, ellipsoidal, uniformly shaped oocysts measuring 5 × 3 μm. The two new species share traits, which define the genus such as: gamonts in association, satellites with characteristic flange and gametocysts dehiscence through a single pore. The epimerite of P. globuloepimeritum is hyaline and globular, which is unique among members of the genus. The gametocyst of P. elliptica is notably ellipsoidal. Basing on observation on all the described and present two species, generic characters of the genus Phleobum have been redefined. The genus is also transferred from the family Didymophyidae to the family Hirmocystidae as the gametocysts in all the species of Phleobum dehisce through a pore.
Publication date: 31.12.2010
Editor-in-Chief: Krzysztof Wiąckowski
Pamela A. Santibáñez A., Shiro Kohshima, Rodrigo A. Scheihing A, Ricardo Silva R, Jorge I. Jaramillo M, Pedro J. Labarca P, Gino Casassa R.
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 1-14
https://doi.org/10.4467/16890027AP.11.001.0001This study documents for the first time the presence of testate amoebae on glaciers. Three shallow firn cores of 10 m depth were obtained from the Mocho-Choshuenco and Osorno volcanoes, Southern Andes, Chile, in October and November, 2005. Euglyphid testate amoebae were detected in 28 samples that correspond to the spring-summer layers of the firn cores. Inspection of 454 collected individuals reveals the presence of four different taxa. Three of these taxa, Trinema lineare, Trinema enchelys and Puytoracia bergeri have previously been reported in ice-free environments. The fourth taxon corresponds to a new species Puytoracia jenswendti nov. sp. The observation of food content and reproductive activities in a significant fraction of specimens evidence that testate amoebae are competent to inhabit glaciers. The testate amoebae found in the firn cores display clear seasonal variations in abundance indicating that these records can provide a new and novel proxy as paleoindicator for firn/ice core dating and for estimation of past glacier mass balance.
O. Roger Anderson
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 15-22
https://doi.org/10.4467/16890027AP.11.002.0002Naked amoeba densities, sizes, biodiversity and carbon content were examined in relation to two particle size fractions (< 200 μm and > 200 μm) of suspended matter in the water column of the Hudson Estuary at a near-shore location south of the Tappan Zee, Palisades, New York. The densities varied markedly among the two particle fractions, and therefore the mean densities were not significantly different between the larger and smaller particle fractions. In contrast, the mean sizes and mean carbon content were statistically greater on larger size suspended particles compared to smaller size particles. There was a broader size range of amoebae on the larger particles, including very large Cochliopodium, Vannella, Mayorella, and Hartmannella species suggesting a larger biodiversity, also indicated by a larger diversity coefficient for the > 200-μm-particle fraction compared to the < 200-μm-particle fraction, 4.51 and 4.18, respectively. In conclusion, the size of suspended particulates in the water column of near-shore, estuarine habitats may have a significant influence on the composition of naked amoebae communities and their ecological roles, especially the organization of particle-associated microbial food webs.
Paul J. Bischoff, Thomas G. Horvath
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 23-31
https://doi.org/10.4467/16890027AP.11.003.0003Zebra mussels (Dreissena polymorpha) are bivalve mollusks that have invaded and altered the ecology of many North American lakes and rivers. To identify possible ecological effects of zebra mussels on naked amoebae, this study compared abundances of sediment and water column naked amoebae in shallow water zones of four lakes with and four lakes without zebra mussels. Additional data was collected on the density of macroflagellates. Although no statistically significant difference in naked amoebae density was found, higher ratios of sediment to water column naked amoebae abundances in zebra mussel lakes were observed due to increased naked amoebae abundances in the sediments. However, we did not observe a concomitant decrease in water column naked amoebae abundances. Flagellate abundances revealed no significant differences between the two lake types. Taken together, the data show that naked amoebae and flagellates thrive in shallow water zones of zebra mussel lakes and that the filter feeding activities of zebra mussels and reported reduced water column protists abundances may be offset by the flocculation of protists from the rich zebra mussel colonies.
Ivan Cometa, Scott Schatz, Wendy Trzyna, Andrew Rogerson
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 33-40
https://doi.org/10.4467/16890027AP.11.004.0004Amoebae feed on attached bacteria within, and below, bacterial biofilms where they experience reduced oxygen levels. The implications of this were examined by comparing the migration (an index of growth) of thirteen strains of Acanthamoeba and five species of naked amoebae grown under microaerophilic and aerobic conditions. All amoebae replicated well under both conditions and twelve isolates migrated significantly faster under low oxygen. Only one isolate, Vannella sp., migrated further (presumably grew faster) under aerobic conditions. The data show most amoebae prefer low oxygen as befits the biofilm habitat. Interestingly, the eleven acanthamoeba strains that replicated faster under microaerophilic conditions were all T4 genotypes and included four strains isolated from patients with amoeba keratitis (AK) infections. This genotype is most frequently found in AK cases and it is suggested that strains of Acanthamoeba capable of rapid growth in a biofilm of a poorly cleansed contact lens may enable amoebae to multiply and provide an infective dos e when placed onthe cornea.
Johan F. De Jonckheere, Jun Murase, Fred R. Opperdoes
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 41-48
https://doi.org/10.4467/16890027AP.11.005.0005An amoeba was isolated from a soil sample collected at the edge of a fumarole of the volcano Ceboruco in the state of Nayarit, Mexico. The trophozoites of this new isolate have eruptive pseudopodes and do not transform into flagellates. The strain forms cysts that have a double wall. This thermophilic amoeba grows at temperatures up to 50°C. Molecular phylogenetic analysis of the small subunit ribosomal DNA (SSU rDNA) places the amoeba into the Heterolobosea. The closest relatives are Paravahlkampfia spp. Like some other heterolobosean species, this new isolate has a group I intron in the SSU rDNA. Because of its position in the molecular phylogenetic tree, and because there is no species found in the literature with similar morphological and physiological characteristics, this isolate is described as a new genus and a new species, Fumarolamoeba ceborucoi gen. nov., sp. nov.
Daniele Corsaro
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 49-54
https://doi.org/10.4467/16890027AP.11.006.0006Strains of the genus Acanthamoeba are usually assigned to sequence types or genotypes according to pair-wise similarity values of the nuclear gene for the small subunit of ribosomal RNA. This classification system was established by comparing full or nearly full gene sequences, > 2000 bp. For practical reasons, diagnostic fragments of smaller lengths have been identified and used for rapid and economic identification of large number of strains. While the use of these small fragments in diagnostics applications remains valid when and only if the reference full sequence-type is available, we contest their use to identify and describe new genotypes. We report herein the case of a new genotype described on the basis of solely a small partial sequence and discuss the poor reliability of this fragment to correctly infer phylogenetic relationships, and its limits in the description of new genotypes of Acanthamoeba.
Iva Dyková
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 55-63
https://doi.org/10.4467/16890027AP.11.007.0007Five amoeba strains isolated from organs of fish were selected by morphology as possible members of the genus Vexillifera Schaeffer, 1926. Phylogenetic analyses of SSU rDNA sequences revealed that four of these strains form a best supported clade together with Vexillifera minutissima (strain CCAP 1590/3) and V. bacillipedes (sequence of the type culture was newly generated in this study). Comparison of trophozoite morphology and SSU rDNA sequences identified one of the five fish-isolated strains as closely related to V. bacillipedes, and characteristics of another three strains allowed to establish three new species: Vexillifera multispinosa, V. fluvialis and V. tasmaniana. The enlargement of dataset of Vexillifera SSU rDNA sequences enables us to doubt the identification of ATCC strain 50883 designated as V. armata. Since sequence of this strain branched in our analysis in a distant phylogenetic position within Korotnevela and Neoparamoeba clade, the Vexillifera origin of this sequence is called in question. The same applies to the newly generated sequence of the type strain of V. expectata, previously characterised by its morphology only.
Maillo-Bellón Pedro-Andrés, Maria Pilar Gracia-royo, Adam Marques
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 65-69
https://doi.org/10.4467/16890027AP.11.008.0008The ultrastructural characteristics of the sporogenesis of Myxobolus, which infect the brachial arches of Mugil cephalus, is presented. The prevalence of infection was 52.7%. The ultrastructural features of the Myxobolus species studied in general comply with known features of this genus. Based on the ultrastructural morphology and specificity to the host organ, we conclude that this species is Myxobolus ichkeulensis (Bahri and Marques 1996).
Pamela A. Santibáñez A., Shiro Kohshima, Rodrigo A. Scheihing A, Ricardo Silva R, Jorge I. Jaramillo M, Pedro J. Labarca P, Gino Casassa R.
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 1-14
https://doi.org/10.4467/16890027AP.11.001.0001This study documents for the first time the presence of testate amoebae on glaciers. Three shallow firn cores of 10 m depth were obtained from the Mocho-Choshuenco and Osorno volcanoes, Southern Andes, Chile, in October and November, 2005. Euglyphid testate amoebae were detected in 28 samples that correspond to the spring-summer layers of the firn cores. Inspection of 454 collected individuals reveals the presence of four different taxa. Three of these taxa, Trinema lineare, Trinema enchelys and Puytoracia bergeri have previously been reported in ice-free environments. The fourth taxon corresponds to a new species Puytoracia jenswendti nov. sp. The observation of food content and reproductive activities in a significant fraction of specimens evidence that testate amoebae are competent to inhabit glaciers. The testate amoebae found in the firn cores display clear seasonal variations in abundance indicating that these records can provide a new and novel proxy as paleoindicator for firn/ice core dating and for estimation of past glacier mass balance.
O. Roger Anderson
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 15-22
https://doi.org/10.4467/16890027AP.11.002.0002Naked amoeba densities, sizes, biodiversity and carbon content were examined in relation to two particle size fractions (< 200 μm and > 200 μm) of suspended matter in the water column of the Hudson Estuary at a near-shore location south of the Tappan Zee, Palisades, New York. The densities varied markedly among the two particle fractions, and therefore the mean densities were not significantly different between the larger and smaller particle fractions. In contrast, the mean sizes and mean carbon content were statistically greater on larger size suspended particles compared to smaller size particles. There was a broader size range of amoebae on the larger particles, including very large Cochliopodium, Vannella, Mayorella, and Hartmannella species suggesting a larger biodiversity, also indicated by a larger diversity coefficient for the > 200-μm-particle fraction compared to the < 200-μm-particle fraction, 4.51 and 4.18, respectively. In conclusion, the size of suspended particulates in the water column of near-shore, estuarine habitats may have a significant influence on the composition of naked amoebae communities and their ecological roles, especially the organization of particle-associated microbial food webs.
Paul J. Bischoff, Thomas G. Horvath
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 23-31
https://doi.org/10.4467/16890027AP.11.003.0003Zebra mussels (Dreissena polymorpha) are bivalve mollusks that have invaded and altered the ecology of many North American lakes and rivers. To identify possible ecological effects of zebra mussels on naked amoebae, this study compared abundances of sediment and water column naked amoebae in shallow water zones of four lakes with and four lakes without zebra mussels. Additional data was collected on the density of macroflagellates. Although no statistically significant difference in naked amoebae density was found, higher ratios of sediment to water column naked amoebae abundances in zebra mussel lakes were observed due to increased naked amoebae abundances in the sediments. However, we did not observe a concomitant decrease in water column naked amoebae abundances. Flagellate abundances revealed no significant differences between the two lake types. Taken together, the data show that naked amoebae and flagellates thrive in shallow water zones of zebra mussel lakes and that the filter feeding activities of zebra mussels and reported reduced water column protists abundances may be offset by the flocculation of protists from the rich zebra mussel colonies.
Ivan Cometa, Scott Schatz, Wendy Trzyna, Andrew Rogerson
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 33-40
https://doi.org/10.4467/16890027AP.11.004.0004Amoebae feed on attached bacteria within, and below, bacterial biofilms where they experience reduced oxygen levels. The implications of this were examined by comparing the migration (an index of growth) of thirteen strains of Acanthamoeba and five species of naked amoebae grown under microaerophilic and aerobic conditions. All amoebae replicated well under both conditions and twelve isolates migrated significantly faster under low oxygen. Only one isolate, Vannella sp., migrated further (presumably grew faster) under aerobic conditions. The data show most amoebae prefer low oxygen as befits the biofilm habitat. Interestingly, the eleven acanthamoeba strains that replicated faster under microaerophilic conditions were all T4 genotypes and included four strains isolated from patients with amoeba keratitis (AK) infections. This genotype is most frequently found in AK cases and it is suggested that strains of Acanthamoeba capable of rapid growth in a biofilm of a poorly cleansed contact lens may enable amoebae to multiply and provide an infective dos e when placed onthe cornea.
Johan F. De Jonckheere, Jun Murase, Fred R. Opperdoes
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 41-48
https://doi.org/10.4467/16890027AP.11.005.0005An amoeba was isolated from a soil sample collected at the edge of a fumarole of the volcano Ceboruco in the state of Nayarit, Mexico. The trophozoites of this new isolate have eruptive pseudopodes and do not transform into flagellates. The strain forms cysts that have a double wall. This thermophilic amoeba grows at temperatures up to 50°C. Molecular phylogenetic analysis of the small subunit ribosomal DNA (SSU rDNA) places the amoeba into the Heterolobosea. The closest relatives are Paravahlkampfia spp. Like some other heterolobosean species, this new isolate has a group I intron in the SSU rDNA. Because of its position in the molecular phylogenetic tree, and because there is no species found in the literature with similar morphological and physiological characteristics, this isolate is described as a new genus and a new species, Fumarolamoeba ceborucoi gen. nov., sp. nov.
Daniele Corsaro
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 49-54
https://doi.org/10.4467/16890027AP.11.006.0006Strains of the genus Acanthamoeba are usually assigned to sequence types or genotypes according to pair-wise similarity values of the nuclear gene for the small subunit of ribosomal RNA. This classification system was established by comparing full or nearly full gene sequences, > 2000 bp. For practical reasons, diagnostic fragments of smaller lengths have been identified and used for rapid and economic identification of large number of strains. While the use of these small fragments in diagnostics applications remains valid when and only if the reference full sequence-type is available, we contest their use to identify and describe new genotypes. We report herein the case of a new genotype described on the basis of solely a small partial sequence and discuss the poor reliability of this fragment to correctly infer phylogenetic relationships, and its limits in the description of new genotypes of Acanthamoeba.
Iva Dyková
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 55-63
https://doi.org/10.4467/16890027AP.11.007.0007Five amoeba strains isolated from organs of fish were selected by morphology as possible members of the genus Vexillifera Schaeffer, 1926. Phylogenetic analyses of SSU rDNA sequences revealed that four of these strains form a best supported clade together with Vexillifera minutissima (strain CCAP 1590/3) and V. bacillipedes (sequence of the type culture was newly generated in this study). Comparison of trophozoite morphology and SSU rDNA sequences identified one of the five fish-isolated strains as closely related to V. bacillipedes, and characteristics of another three strains allowed to establish three new species: Vexillifera multispinosa, V. fluvialis and V. tasmaniana. The enlargement of dataset of Vexillifera SSU rDNA sequences enables us to doubt the identification of ATCC strain 50883 designated as V. armata. Since sequence of this strain branched in our analysis in a distant phylogenetic position within Korotnevela and Neoparamoeba clade, the Vexillifera origin of this sequence is called in question. The same applies to the newly generated sequence of the type strain of V. expectata, previously characterised by its morphology only.
Maillo-Bellón Pedro-Andrés, Maria Pilar Gracia-royo, Adam Marques
Acta Protozoologica, Volume 50, Issue 1, 2011, pp. 65-69
https://doi.org/10.4467/16890027AP.11.008.0008The ultrastructural characteristics of the sporogenesis of Myxobolus, which infect the brachial arches of Mugil cephalus, is presented. The prevalence of infection was 52.7%. The ultrastructural features of the Myxobolus species studied in general comply with known features of this genus. Based on the ultrastructural morphology and specificity to the host organ, we conclude that this species is Myxobolus ichkeulensis (Bahri and Marques 1996).
Publication date: 2010
Editor-in-Chief: Krzysztof Wiąckowski
Almut Gerhardt, Asad Ud-Daula, Karl-Werner Schramm
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 271-280
This review summarizes the application of Tetrahymena spp. in ecotoxicology, in order to promote a more integrated, multi-level ecotoxicological assessment approach regarding the effects of chemical stressors on several biological levels (from molecule to ecosystem). Such a multi-level testing approach in one species facilitates the establishment of missing causal relationships between biochemical responses and ecological effects. The review illustrates that Tetrahymena spp. represent excellent ecotoxicological test species due to their important role in the microbial foodweb, wide distribution and abundance, sequenced genome in T. thermophila, large background knowledge and scientific publications in cellular biology, ecology and ecotoxicology. Several bioassays have already been developed on different biological organisation levels, such as enzyme assays (biochemical level), behavioral tests (individual level), population growth tests (population level) and microcosms (community level). Moreover, specific mode-of-action based assays are available (e.g. genotoxicity), or are in development (e.g. endocrine disruption and neurotoxicity). Tetrahymena spp. combine traits of (1) a single cell, thus might replace or complement specific cell-line testing approaches, with traits of (2) a whole organism and population, thus allowing to study complete metabolic pathways and its consequences on population growth and genetic adaptation. Assays involving Tetrahymena spp. might easily be adapted for a rapid multi-level in situ or ex situ toxicity biosensor test system for ecologically relevant risk assessment.
Eun Hye Lee, Ki Hong Kim
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 281-288
Complementary DNAs (cDNAs) of protein phosphatase 2C (PP2C) were cloned from two marine scuticociliates Uronema marinum and Miamiensis avidus. Both PP2C proteins showed structural characteristics of typical PP2C, such as highly conserved amino acid residues predicted for binding to phosphate and metal ions, 11 conserved PP2C motifs and 10 invariant residues. The phosphatase activity of recombinantly produced U. marinum PP2C (UmPP2C) was in proportion to the PP2C protein and Mg2+ concentrations, and was not sensitive to okadaic acid, but was inhibited by sodium fluoride, EDTA or Ca2+. The expression of UmPP2C was significantly up-regulated by exposure the ciliates with PMA suggesting that UmPP2C dephosphrylates proteins phosphorylated by protein kinases as in other eukaryotes and has a regulatory function against abrupt increase of protein phosphorylation triggered by strong stimulations.
Stephen N. Smith, Jamshaid A. Khan, Richard A. Armstrong, Bishal Mohindru, Mark Prince, John M. Whipps
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 289-300
Acanthamoeba polyphaga trophozoites bind yeast cells of Candida albicans isolates within a few hours, leaving few cells in suspension or still attached to trophozoite surfaces. The nature of yeast cell recognition, mediated by an acanthamoebal trophozoite mannose binding protein is confi rmed by experiments utilizing concentration dependent mannose hapten blocking. Similarly, acapsulate cells of Cryptococcus neoformans are also bound within a relatively short timescale. However, even after protracted incubation many capsulate cells of Cryptococcus remain in suspension, suggesting that the capsulate cell form of this species is not predated by acanthamoebal trophozoites.
Further aspects of the association of Acanthamoeba and fungi are apparent when studying their interaction with conidia of the biocontrol agent Coniothyrium minitans. Conidia which readily bind with increasing maturity of up to 42 days, were little endocytosed and even released. Cell and conidial surface mannose as determined by FITC-lectin binding, fl ow cytometry with associated ligand binding analysis and hapten blocking studies demonstrates the following phenomena. Candida isolates and acapsulate Cryptococcus expose most mannose, while capsulate Cryptococcus cells exhibit least exposure commensurate with yeast cellular binding or lack of trophozoites. Conidia of Coniothyrium, albeit in a localized fashion, also manifest surface mannose exposure but as shown by Bmax values, in decreasing amounts with increasing maturity. Contrastingly such conidia experience greater trophozoite binding with maturation, thereby questioning the primacy of a trophozoite mannose-binding-protein recognition model.
Pavel Široky, David Modrý
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 301-310
The genus Eimeria Schneider, 1875, comprises of > 1,000 described species, making it the most species-rich among coccidians. Within chelonian hosts, only 61 Eimeria spp. have been described to date, with the majority known from the New World. Yet, the Southeast Asia region has the highest turtle diversity in the world, from which only a few species have been discovered. Furthermore, the largest turtle family, Geoemydidae Theobald, 1868, has received little attention. In the past decade we examined samples from wild-caught geoemydid turtles from Southeast Asia and adjacent areas. Our work revealed considerable diversity of turtles’ coccidia and we describe six new species of Eimeria in this report. Eimeria surinensis sp. n. from Malayemys subtrijuga caught in Thailand possesses almost spherical oocysts (22.6 × 21.4), with spindle-shaped to ellipsoidal sporocysts pointed at both poles (13.4 × 6.9). Eimeria pangshurae sp. n. from Pangshura sylhetensis residing in India has ellipsoidal to spherical oocysts (16.5 × 13.2) and broadly-ellipsoidal to fl ask-shaped sporocysts (11.1 × 5.7), with a Stieda body frequently connected with two to four fi laments. Eimeria hynekprokopi sp. n. from Vietnamese Cuora galbinifrons has extremely thin-walled and fragile, elongated oocysts, and is a bit pointed at one pole (15.6 × 8.7), carrying ellipsoidal to broadly oval sporocysts (6.5 × 4.3). Eimeria zbatagura sp. n. from Batagur baska sampled in Singapore has tiny sub-spherical to broadly ellipsoidal oocysts (7.4 × 6.3 μm) with almost oval but relatively small sporocysts (5.5 × 3 μm). The broadly ellipsoidal, fragile oocysts of Eimeria petrasi sp. n. (22.9 × 18.6 μm) collected from Cyclemys dentata in the Philippines possess a wavy outer surface of the oocyst wall, and oval to ellipsoidal sporocysts (12.3 × 6.5 μm). Eimeria palawanensis sp. n. from Cyclemys dentata found in the Philippines has thin-walled and fragile spherical oocysts (14–17 μm wide), plus elongated, ellipsoidal sporocysts (12.6 × 5.8 μm). We also recorded Eimeria arakanensis Široky et Modry, 2006 from the new host species – Cuora fl avomarginata collected in China. Since many chelonians are critically endangered species, their parasite biodiversity will be lost following the collapse of their populations.
Anatoly Bobrov, Yuri A. Mazei, Alexei V. Tiunov
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 311-325
The composition (143 species and forms) of testate amoebae communities from 68 samples of soils and lake sediments from South Vietnam (Cat Tien National Park) was investigated. In most terrestrial habitats, hydrophilous, soil and even xerophilous testaceans were co-occurring. The likely reason for this phenomenon are sharp seasonal changes in hydrological regime including temporal overwetting or inundation. Typical members of soil communities were Plagiopyxis callida, Tracheleuglypha acolla, Euglypha cristata, E. tuberculata, Trinema complanatum. The fauna was composed mainly of eurybiont species. Less abundant but still common were moss-dwelling species from the genera Heleopera, Hyalosphenia, Nebela and Sphenoderia. Calciphilous species were also present, including Centropyxis plagiostoma, Geopyxella cf. sylvicola, Schwabia terricola, Plagiopyxis callida, P. intermedia v. cyrtostoma, Heleopera petricola v. humicola. Species from the genera Hoogenraadia, Planhoogenraadia, Apolimia were found in this region of South-East Asia for the first time. The variations in the species composition and diversity of testate amoebae in soils was likely caused by several mechanisms including local variations in hydrological regime, the differences in chemical and physical properties and decomposition rates of plant litter, and mineralogical features of soils. The fauna of lake sediments was very distinct with characteristic species Difflugia bacillariarum, Lesquereusia modesta, Arcella gibbosa, Euglypha acanthophora. In the relatively uniform lake sediments local microcommunities were rich in species but very similar in species composition (low beta-diversity). In contrast, in soil samples the micro-scale heterogeneity was usually very pronounced, though the alpha-diversity was lower than in lake sediments. The updated list of testate amoebae of Vietnam includes 237 taxa. Taxa with restricted geographical distribution form up to one tenth of the total species richness.
Liqiong Li, Qianqian Zhang, Khaled A. S. Al-Rasheid, Choon Bong Kwon, Mann Kyoon Shin
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 327-337
The largest known Aspidisca species, A. magna Kahl, 1932, was found from coastal waters near Qingdao (Tsingtao), northern China, and investigated using both the “wet” silver nitrate and protargol staining method. Based on the living observation and impregnated individuals, improved diagnosis and morphometric data are provided. As an additional contribution, the morphogenesis in Aspidisca magna during binary fission was revealed and summarized as follows: 1) the parental adoral zone of membranelles and paroral membranęare retained by the proter; 2) the oral primordium of the opisthe develops hypoapokinetally behind the posterior part of the adoral zone of membranelles; 3) five frontoventral-transverse cirral anlagen are formed de novo, initially as primary primordia, and develop into 3:3:2:2:1 cirri from left to right, respectively in both dividers; 4) the leftmost frontoventral cirrus is generated from an independently formed cirral anlage in both dividers. In the present work, Chinese and Korean populations of A. leptaspis Fresenius, 1865 were investigated respectively to support the importance of living characteristics in identification of Aspidisca species. The isolation of A. magna and A. leptaspis from other congeners are also firmly demonstrated by the SSU rRNA gene sequence alignments.
Santosh Kumar, Komal Kamra, Rai Sapra
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 339-364
The Silent Valley National Park in the state of Kerala, India, ranks high among the biodiversity hotspots of the world with 4.8 as the alpha diversity index. The Valley is surrounded by mountain ranges and has a diverse topography with a mosaic of varied habitats that have remained isolated from extraneous influences. The present report describes urostyloid ciliates from diverse ecozones within the core zone of the National Park. Six species of the urostyloids, including Anteholosticha angida n. sp. and Bakuella nilgiri n. sp., were found in soil samples. Anteholosticha angida n. sp. differs from its cogeners in having a unique combination of characters – presence of colourless cortical granules, ~ 53 macronuclear nodules, ~ 3 micronuclei, ciliature with 3–4 buccal cirri in a row and 4 dorsal kineties. Bakuella nilgiri n. sp. is characterized by the presence of colourless cortical granules, ~ 98 macronuclear nodules, 3–4 micronuclei, ciliature with 4–8 buccal cirri in a row and a mid-ventral complex comprising of ~ 21 cirral pairs and 2–10 cirri in 2–3 rows reaching up to the level of the 6–11 transverse cirri.
Fernando Gómez
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 365-372
The noctilucoid dinoflagellates have been investigated in the open waters of the Mediterranean Sea. Kofoidinium spp., Spatulodinium spp. and Scaphodinium mirabile were found in nearly all the stations. The genera Craspedotella, Leptodiscus, Petalodinium and Pomatodinium were recorded for the first time in the eastern Mediterranean basin. An undescribed small species of Kofoidinium (40–60 μm in diameter) with a pointed extension represented about 1/3 of the genus records. The monotypic character of the genus Spatulodinium needs to be reconsidered because numerous specimens differed from the type species. One of these undescribed species showed a distinctive hyposome and an extremely long tentacle (up to 1600 μm long). A leptodiscacean that showed an arrowhead-shaped contour is found for the first time in the Mediterranean Sea. There is a considerable diversity of noctilucaceans yet to be described.
Almut Gerhardt, Asad Ud-Daula, Karl-Werner Schramm
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 271-280
This review summarizes the application of Tetrahymena spp. in ecotoxicology, in order to promote a more integrated, multi-level ecotoxicological assessment approach regarding the effects of chemical stressors on several biological levels (from molecule to ecosystem). Such a multi-level testing approach in one species facilitates the establishment of missing causal relationships between biochemical responses and ecological effects. The review illustrates that Tetrahymena spp. represent excellent ecotoxicological test species due to their important role in the microbial foodweb, wide distribution and abundance, sequenced genome in T. thermophila, large background knowledge and scientific publications in cellular biology, ecology and ecotoxicology. Several bioassays have already been developed on different biological organisation levels, such as enzyme assays (biochemical level), behavioral tests (individual level), population growth tests (population level) and microcosms (community level). Moreover, specific mode-of-action based assays are available (e.g. genotoxicity), or are in development (e.g. endocrine disruption and neurotoxicity). Tetrahymena spp. combine traits of (1) a single cell, thus might replace or complement specific cell-line testing approaches, with traits of (2) a whole organism and population, thus allowing to study complete metabolic pathways and its consequences on population growth and genetic adaptation. Assays involving Tetrahymena spp. might easily be adapted for a rapid multi-level in situ or ex situ toxicity biosensor test system for ecologically relevant risk assessment.
Eun Hye Lee, Ki Hong Kim
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 281-288
Complementary DNAs (cDNAs) of protein phosphatase 2C (PP2C) were cloned from two marine scuticociliates Uronema marinum and Miamiensis avidus. Both PP2C proteins showed structural characteristics of typical PP2C, such as highly conserved amino acid residues predicted for binding to phosphate and metal ions, 11 conserved PP2C motifs and 10 invariant residues. The phosphatase activity of recombinantly produced U. marinum PP2C (UmPP2C) was in proportion to the PP2C protein and Mg2+ concentrations, and was not sensitive to okadaic acid, but was inhibited by sodium fluoride, EDTA or Ca2+. The expression of UmPP2C was significantly up-regulated by exposure the ciliates with PMA suggesting that UmPP2C dephosphrylates proteins phosphorylated by protein kinases as in other eukaryotes and has a regulatory function against abrupt increase of protein phosphorylation triggered by strong stimulations.
Stephen N. Smith, Jamshaid A. Khan, Richard A. Armstrong, Bishal Mohindru, Mark Prince, John M. Whipps
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 289-300
Acanthamoeba polyphaga trophozoites bind yeast cells of Candida albicans isolates within a few hours, leaving few cells in suspension or still attached to trophozoite surfaces. The nature of yeast cell recognition, mediated by an acanthamoebal trophozoite mannose binding protein is confi rmed by experiments utilizing concentration dependent mannose hapten blocking. Similarly, acapsulate cells of Cryptococcus neoformans are also bound within a relatively short timescale. However, even after protracted incubation many capsulate cells of Cryptococcus remain in suspension, suggesting that the capsulate cell form of this species is not predated by acanthamoebal trophozoites.
Further aspects of the association of Acanthamoeba and fungi are apparent when studying their interaction with conidia of the biocontrol agent Coniothyrium minitans. Conidia which readily bind with increasing maturity of up to 42 days, were little endocytosed and even released. Cell and conidial surface mannose as determined by FITC-lectin binding, fl ow cytometry with associated ligand binding analysis and hapten blocking studies demonstrates the following phenomena. Candida isolates and acapsulate Cryptococcus expose most mannose, while capsulate Cryptococcus cells exhibit least exposure commensurate with yeast cellular binding or lack of trophozoites. Conidia of Coniothyrium, albeit in a localized fashion, also manifest surface mannose exposure but as shown by Bmax values, in decreasing amounts with increasing maturity. Contrastingly such conidia experience greater trophozoite binding with maturation, thereby questioning the primacy of a trophozoite mannose-binding-protein recognition model.
Pavel Široky, David Modrý
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 301-310
The genus Eimeria Schneider, 1875, comprises of > 1,000 described species, making it the most species-rich among coccidians. Within chelonian hosts, only 61 Eimeria spp. have been described to date, with the majority known from the New World. Yet, the Southeast Asia region has the highest turtle diversity in the world, from which only a few species have been discovered. Furthermore, the largest turtle family, Geoemydidae Theobald, 1868, has received little attention. In the past decade we examined samples from wild-caught geoemydid turtles from Southeast Asia and adjacent areas. Our work revealed considerable diversity of turtles’ coccidia and we describe six new species of Eimeria in this report. Eimeria surinensis sp. n. from Malayemys subtrijuga caught in Thailand possesses almost spherical oocysts (22.6 × 21.4), with spindle-shaped to ellipsoidal sporocysts pointed at both poles (13.4 × 6.9). Eimeria pangshurae sp. n. from Pangshura sylhetensis residing in India has ellipsoidal to spherical oocysts (16.5 × 13.2) and broadly-ellipsoidal to fl ask-shaped sporocysts (11.1 × 5.7), with a Stieda body frequently connected with two to four fi laments. Eimeria hynekprokopi sp. n. from Vietnamese Cuora galbinifrons has extremely thin-walled and fragile, elongated oocysts, and is a bit pointed at one pole (15.6 × 8.7), carrying ellipsoidal to broadly oval sporocysts (6.5 × 4.3). Eimeria zbatagura sp. n. from Batagur baska sampled in Singapore has tiny sub-spherical to broadly ellipsoidal oocysts (7.4 × 6.3 μm) with almost oval but relatively small sporocysts (5.5 × 3 μm). The broadly ellipsoidal, fragile oocysts of Eimeria petrasi sp. n. (22.9 × 18.6 μm) collected from Cyclemys dentata in the Philippines possess a wavy outer surface of the oocyst wall, and oval to ellipsoidal sporocysts (12.3 × 6.5 μm). Eimeria palawanensis sp. n. from Cyclemys dentata found in the Philippines has thin-walled and fragile spherical oocysts (14–17 μm wide), plus elongated, ellipsoidal sporocysts (12.6 × 5.8 μm). We also recorded Eimeria arakanensis Široky et Modry, 2006 from the new host species – Cuora fl avomarginata collected in China. Since many chelonians are critically endangered species, their parasite biodiversity will be lost following the collapse of their populations.
Anatoly Bobrov, Yuri A. Mazei, Alexei V. Tiunov
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 311-325
The composition (143 species and forms) of testate amoebae communities from 68 samples of soils and lake sediments from South Vietnam (Cat Tien National Park) was investigated. In most terrestrial habitats, hydrophilous, soil and even xerophilous testaceans were co-occurring. The likely reason for this phenomenon are sharp seasonal changes in hydrological regime including temporal overwetting or inundation. Typical members of soil communities were Plagiopyxis callida, Tracheleuglypha acolla, Euglypha cristata, E. tuberculata, Trinema complanatum. The fauna was composed mainly of eurybiont species. Less abundant but still common were moss-dwelling species from the genera Heleopera, Hyalosphenia, Nebela and Sphenoderia. Calciphilous species were also present, including Centropyxis plagiostoma, Geopyxella cf. sylvicola, Schwabia terricola, Plagiopyxis callida, P. intermedia v. cyrtostoma, Heleopera petricola v. humicola. Species from the genera Hoogenraadia, Planhoogenraadia, Apolimia were found in this region of South-East Asia for the first time. The variations in the species composition and diversity of testate amoebae in soils was likely caused by several mechanisms including local variations in hydrological regime, the differences in chemical and physical properties and decomposition rates of plant litter, and mineralogical features of soils. The fauna of lake sediments was very distinct with characteristic species Difflugia bacillariarum, Lesquereusia modesta, Arcella gibbosa, Euglypha acanthophora. In the relatively uniform lake sediments local microcommunities were rich in species but very similar in species composition (low beta-diversity). In contrast, in soil samples the micro-scale heterogeneity was usually very pronounced, though the alpha-diversity was lower than in lake sediments. The updated list of testate amoebae of Vietnam includes 237 taxa. Taxa with restricted geographical distribution form up to one tenth of the total species richness.
Liqiong Li, Qianqian Zhang, Khaled A. S. Al-Rasheid, Choon Bong Kwon, Mann Kyoon Shin
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 327-337
The largest known Aspidisca species, A. magna Kahl, 1932, was found from coastal waters near Qingdao (Tsingtao), northern China, and investigated using both the “wet” silver nitrate and protargol staining method. Based on the living observation and impregnated individuals, improved diagnosis and morphometric data are provided. As an additional contribution, the morphogenesis in Aspidisca magna during binary fission was revealed and summarized as follows: 1) the parental adoral zone of membranelles and paroral membranęare retained by the proter; 2) the oral primordium of the opisthe develops hypoapokinetally behind the posterior part of the adoral zone of membranelles; 3) five frontoventral-transverse cirral anlagen are formed de novo, initially as primary primordia, and develop into 3:3:2:2:1 cirri from left to right, respectively in both dividers; 4) the leftmost frontoventral cirrus is generated from an independently formed cirral anlage in both dividers. In the present work, Chinese and Korean populations of A. leptaspis Fresenius, 1865 were investigated respectively to support the importance of living characteristics in identification of Aspidisca species. The isolation of A. magna and A. leptaspis from other congeners are also firmly demonstrated by the SSU rRNA gene sequence alignments.
Santosh Kumar, Komal Kamra, Rai Sapra
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 339-364
The Silent Valley National Park in the state of Kerala, India, ranks high among the biodiversity hotspots of the world with 4.8 as the alpha diversity index. The Valley is surrounded by mountain ranges and has a diverse topography with a mosaic of varied habitats that have remained isolated from extraneous influences. The present report describes urostyloid ciliates from diverse ecozones within the core zone of the National Park. Six species of the urostyloids, including Anteholosticha angida n. sp. and Bakuella nilgiri n. sp., were found in soil samples. Anteholosticha angida n. sp. differs from its cogeners in having a unique combination of characters – presence of colourless cortical granules, ~ 53 macronuclear nodules, ~ 3 micronuclei, ciliature with 3–4 buccal cirri in a row and 4 dorsal kineties. Bakuella nilgiri n. sp. is characterized by the presence of colourless cortical granules, ~ 98 macronuclear nodules, 3–4 micronuclei, ciliature with 4–8 buccal cirri in a row and a mid-ventral complex comprising of ~ 21 cirral pairs and 2–10 cirri in 2–3 rows reaching up to the level of the 6–11 transverse cirri.
Fernando Gómez
Acta Protozoologica, Volume 49, Issue 4, 2010, pp. 365-372
The noctilucoid dinoflagellates have been investigated in the open waters of the Mediterranean Sea. Kofoidinium spp., Spatulodinium spp. and Scaphodinium mirabile were found in nearly all the stations. The genera Craspedotella, Leptodiscus, Petalodinium and Pomatodinium were recorded for the first time in the eastern Mediterranean basin. An undescribed small species of Kofoidinium (40–60 μm in diameter) with a pointed extension represented about 1/3 of the genus records. The monotypic character of the genus Spatulodinium needs to be reconsidered because numerous specimens differed from the type species. One of these undescribed species showed a distinctive hyposome and an extremely long tentacle (up to 1600 μm long). A leptodiscacean that showed an arrowhead-shaped contour is found for the first time in the Mediterranean Sea. There is a considerable diversity of noctilucaceans yet to be described.
Publication date: 30.06.2010
Editor-in-Chief: Krzysztof Wiąckowski
Markus Thamm, Stephanie L. Schmidt, Detlef Bernhard
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 149-157
Representatives of the genus Stentor (Stentoridae, Heterotrichea) are striking ciliates in environmentalwater samples because of their size (up to 4 mm) and their trumpet-like shape. Important for species identification are the following main characteristics: (1) the presence or absence of endosymbiotic algae (zoochlorellae); (2) the colour of the pigmented cortical granules, and (3) the shape of the macronucleus. The complete small subunit rDNA (SSU rDNA) of 19 further representatives of the genus Stentor was sequenced to examine the phylogenetic relationships within this genus and to determine the taxonomic value of these main characteristics. The detailed phylogenetic analyses yielded a separation of all species possessing a single compact macronucleus from those species with an “elongated” macronucleus (moniliform or vermiform). The data also indicate that the uptake of algae as well as the loss of pigmentation happened independently in different lineages. Furthermore, a high level of intraspecific variation within several species was found. Thus, S. muelleri and S. (sp.) cf. katashimai appear to represent distinct species and S. multiformis is composed of a species complex.
Wilhelm Foissner
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 159-193
Bromeliothrix metopoides was discovered in tank bromeliads from Central and South America. Pure cultures could be established in various media stimulating growth of its food, i.e. bacteria and heterotrophic flagellates of the genus Polytomella. The new ciliate was investigated in the light- and scanning electron microscope, with various silver impregnation techniques, and with molecular methods, using the small-subunit rDNA. The morphology and its changes during the life cycle are documented by 167 figures and a detailed morphometry. Bromeliothrix metopoides is about 27–55 × 22–36 μm in size and has a complex life cycle with Metopus-shaped, bacteriophagous theronts and trophonts (microstomes) and obovate, flagellate-feeding macrostomes having a large, triangular oral apparatus. The thin-walled
Liqiong Li, Jie Huang, Weibo Song, Mann Kyoon Shin, Khaled A. S. Al-Rasheid, Helmut Berger
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 195-212
The morphology, the infraciliature, some stages of cell division and physiological reorganization, and the SSU rRNA gene sequence of the little-known marine 18-cirri hypotrich Tachysoma rigescens (Kahl, 1932) Borror, 1972 [basionym Oxytricha (Tachysoma) rigescens], isolated from mariculture waters near Qingdao, China, were investigated. This rare species is characterized, inter alia, by narrowly spaced, small, colourless cortical granules and several conspicuous ring-shaped structures in the cytoplasm. The caudal cirri and the simple dorsal kinety pattern (three bipolar kineties) are probably plesiomorphic traits within the Hypotricha, the composition of the adoral zone of the proter from new and parental membranelles, as well as the presence of two ‘extra’ cirri behind the right marginal row strongly suggest a misclassification in Tachysoma. The SSU rRNA gene sequence data indicate that T. rigescens branches off rather basally in the Hypotricha tree, which supports the hypothesis that the 18-cirri pattern occurred very early, probably already in the last common ancestor of the Hypotricha. A detailed survey of the early branching 18-cirri hypotrichs and similar taxa (e.g. Trachelostyla pediculiformis, Hemigastrostyla enigmatica, Protogastrostyla pulchra) reveals that for T. rigescens a new genus (Apogastrostyla gen. nov.) has to be established, because there are important differences, inter alia, in the dorsal infraciliature. Besides the type species, A. rigescens comb. nov., which seems to be confined to the northern hemisphere according to the sparse faunistic data, a second marine species, A. szaboi comb. nov. (basionym Hemigastrostyla szaboi), so far only twice recorded from the Antarctic region, can be included. The Chinese population is fixed as neotype to define the species objectively, because no type material of A. rigescens is present and the original type locality is not known. The species name Tachysoma multinucleate is emended: Tachysoma multinucleatum nom. corr.
Sabine Agatha
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 213-234
Tintinnopsis parvula Jörgensen, 1912 has apparently a cosmopolitan distribution in the pelagial of marine and brackish coastal waters. The species is redescribed based on material from the Irish Sea off the Isle of Man, using live observation, protargol impregnation, and scanning electron microscopy. The agglomerated and stiff lorica measures 38–60 × 24–31 μm and is composed of a usually broadly obovate bowl and a slightly narrowed cylindroidal collar with an inner diameter of ~ 20 μm. The somatic ciliary pattern is of the most complex type, viz., it comprises a ventral, dorsal, and posterior kinety as well as a right, left, and lateral ciliary field. The left ciliary field comprises four kineties, the lateral field about ten kineties, and the right field five kineties. The oral primordium develops apparently apokinetally posterior to the lateral ciliary field and generates ~ 15 collar membranelles and one buccal membranelle. Two further populations were studied: one from the North Sea off the Island of Sylt, the other from brackish polder basins at the German North Sea coast; they match the Irish Sea specimens in all main features. The loricae formed in almost particle-free cultures have a thin wall composed of an irregular network of fibres and very few attached or interwoven particles. This matrix type differs from the other three types found in congeners. Hence, the matrix ultrastructure might represent a promising feature for a reliable subdivision of the species-rich genus Tintinnopsis Stein, 1867 in the future.
Morphology and Ecology in Tintinnid Ciliates of the Marine Plankton: Correlates of Lorica Dimensions
John R. Dolan
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 235-244
Tintinnid ciliates, characterized by the possession of a lorica into which the ciliate cell can contract, are a common component of the marine microzooplankton. Lorica architecture and size range widely and classically distinguishes species. Here relationships between ecological parameters and lorica dimensions (lorica oral diameter (LOD), lorica length (LL) and lorica volume (LV) are examined using data from literature reports. The relationships between lorica dimensions and reproductive potential, using maximum reported growth rates of natural populations (n = 52 species) are assessed. Susceptibility to copepod predation and lorica dimensions are considered based on reports of clearance rates of Acartia species feeding on tintinnid ciliates (n = 7 species). Diet and lorica dimension is analyzed using data on mean maximum food size contained in field-caught cells (n = 20 species), and preferred food size based on prey size associated with maximal reported clearance rates (n = 15 species). Overall, LOD is closely related to most of the ecological parameters. Maximum growth rate is related to LOD with smaller LODs corresponding to higher growth rates, in contrast to LL and LV. Maximum prey size is positively related to both LOD and LL but more tightly with LOD. Preferred prey size is positively related to LOD and LV but more tightly related to LOD. Clearance rates of Acartia species feeding on tintinnids are significantly related only to LOD with small LODs corresponding to lower copepod feeding rates. Relationships excluding data on species of Tintinnopsis, the species-rich genus which generally dominates coastal communities, are also examined and show similar trends. In tintinnids, LOD, known to be a conservative and relatively reliable species characteristic, appears related to a wide range of ecological characteristics.
Iva Dyková, Martin Kostka, Hana Pecková
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 245-251
As a result of light microscopical, ultrastructural and molecular study of three amoeba strains isolated from organs of three freshwater fish hosts, Stenamoeba amazonica sp. n. and S. limacina sp. n. are described as new amoeba species. The mutual comparison of isolated strains has extended the knowledge of morphological diversity within the genus Stenamoeba Smirnov, Nassonova, Chao et Cavalier-Smith, 2007. Molecular data obtained for these strains have complemented the phylogenetic tree that so far has contained only one nominal species within the single-genus Stenamoeba clade.
Linda Basson
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 253-265
During parasitological surveys in Tasmania (Australia), four introduced fish species were investigated for the presence of trichodinid ectoparasites. Five trichodinid species were found on the skin, fins and gills of two of these fishes, i.e. the tench Tinca tinca Linnaeus, 1758 and the red fin perch Perca fluviatillis Linnaeus, 1758. Four trichodinids are known species for which comparative descriptions are provided, i.e. Trichodina acuta Lom, 1961, T. esocis Lom, 1961, T. lepsii Lom, 1962 and Trichodinella epizootica (Raabe 1950) Šrámek- Hušek, 1953. A fifth species, i.e. Trichodina tunnae sp. n. is described as a new species from the red fin perch. All species are described using silver impregnated and hematoxylin stained specimens.
Markus Thamm, Stephanie L. Schmidt, Detlef Bernhard
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 149-157
Representatives of the genus Stentor (Stentoridae, Heterotrichea) are striking ciliates in environmentalwater samples because of their size (up to 4 mm) and their trumpet-like shape. Important for species identification are the following main characteristics: (1) the presence or absence of endosymbiotic algae (zoochlorellae); (2) the colour of the pigmented cortical granules, and (3) the shape of the macronucleus. The complete small subunit rDNA (SSU rDNA) of 19 further representatives of the genus Stentor was sequenced to examine the phylogenetic relationships within this genus and to determine the taxonomic value of these main characteristics. The detailed phylogenetic analyses yielded a separation of all species possessing a single compact macronucleus from those species with an “elongated” macronucleus (moniliform or vermiform). The data also indicate that the uptake of algae as well as the loss of pigmentation happened independently in different lineages. Furthermore, a high level of intraspecific variation within several species was found. Thus, S. muelleri and S. (sp.) cf. katashimai appear to represent distinct species and S. multiformis is composed of a species complex.
Wilhelm Foissner
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 159-193
Bromeliothrix metopoides was discovered in tank bromeliads from Central and South America. Pure cultures could be established in various media stimulating growth of its food, i.e. bacteria and heterotrophic flagellates of the genus Polytomella. The new ciliate was investigated in the light- and scanning electron microscope, with various silver impregnation techniques, and with molecular methods, using the small-subunit rDNA. The morphology and its changes during the life cycle are documented by 167 figures and a detailed morphometry. Bromeliothrix metopoides is about 27–55 × 22–36 μm in size and has a complex life cycle with Metopus-shaped, bacteriophagous theronts and trophonts (microstomes) and obovate, flagellate-feeding macrostomes having a large, triangular oral apparatus. The thin-walled
Liqiong Li, Jie Huang, Weibo Song, Mann Kyoon Shin, Khaled A. S. Al-Rasheid, Helmut Berger
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 195-212
The morphology, the infraciliature, some stages of cell division and physiological reorganization, and the SSU rRNA gene sequence of the little-known marine 18-cirri hypotrich Tachysoma rigescens (Kahl, 1932) Borror, 1972 [basionym Oxytricha (Tachysoma) rigescens], isolated from mariculture waters near Qingdao, China, were investigated. This rare species is characterized, inter alia, by narrowly spaced, small, colourless cortical granules and several conspicuous ring-shaped structures in the cytoplasm. The caudal cirri and the simple dorsal kinety pattern (three bipolar kineties) are probably plesiomorphic traits within the Hypotricha, the composition of the adoral zone of the proter from new and parental membranelles, as well as the presence of two ‘extra’ cirri behind the right marginal row strongly suggest a misclassification in Tachysoma. The SSU rRNA gene sequence data indicate that T. rigescens branches off rather basally in the Hypotricha tree, which supports the hypothesis that the 18-cirri pattern occurred very early, probably already in the last common ancestor of the Hypotricha. A detailed survey of the early branching 18-cirri hypotrichs and similar taxa (e.g. Trachelostyla pediculiformis, Hemigastrostyla enigmatica, Protogastrostyla pulchra) reveals that for T. rigescens a new genus (Apogastrostyla gen. nov.) has to be established, because there are important differences, inter alia, in the dorsal infraciliature. Besides the type species, A. rigescens comb. nov., which seems to be confined to the northern hemisphere according to the sparse faunistic data, a second marine species, A. szaboi comb. nov. (basionym Hemigastrostyla szaboi), so far only twice recorded from the Antarctic region, can be included. The Chinese population is fixed as neotype to define the species objectively, because no type material of A. rigescens is present and the original type locality is not known. The species name Tachysoma multinucleate is emended: Tachysoma multinucleatum nom. corr.
Sabine Agatha
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 213-234
Tintinnopsis parvula Jörgensen, 1912 has apparently a cosmopolitan distribution in the pelagial of marine and brackish coastal waters. The species is redescribed based on material from the Irish Sea off the Isle of Man, using live observation, protargol impregnation, and scanning electron microscopy. The agglomerated and stiff lorica measures 38–60 × 24–31 μm and is composed of a usually broadly obovate bowl and a slightly narrowed cylindroidal collar with an inner diameter of ~ 20 μm. The somatic ciliary pattern is of the most complex type, viz., it comprises a ventral, dorsal, and posterior kinety as well as a right, left, and lateral ciliary field. The left ciliary field comprises four kineties, the lateral field about ten kineties, and the right field five kineties. The oral primordium develops apparently apokinetally posterior to the lateral ciliary field and generates ~ 15 collar membranelles and one buccal membranelle. Two further populations were studied: one from the North Sea off the Island of Sylt, the other from brackish polder basins at the German North Sea coast; they match the Irish Sea specimens in all main features. The loricae formed in almost particle-free cultures have a thin wall composed of an irregular network of fibres and very few attached or interwoven particles. This matrix type differs from the other three types found in congeners. Hence, the matrix ultrastructure might represent a promising feature for a reliable subdivision of the species-rich genus Tintinnopsis Stein, 1867 in the future.
Morphology and Ecology in Tintinnid Ciliates of the Marine Plankton: Correlates of Lorica Dimensions
John R. Dolan
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 235-244
Tintinnid ciliates, characterized by the possession of a lorica into which the ciliate cell can contract, are a common component of the marine microzooplankton. Lorica architecture and size range widely and classically distinguishes species. Here relationships between ecological parameters and lorica dimensions (lorica oral diameter (LOD), lorica length (LL) and lorica volume (LV) are examined using data from literature reports. The relationships between lorica dimensions and reproductive potential, using maximum reported growth rates of natural populations (n = 52 species) are assessed. Susceptibility to copepod predation and lorica dimensions are considered based on reports of clearance rates of Acartia species feeding on tintinnid ciliates (n = 7 species). Diet and lorica dimension is analyzed using data on mean maximum food size contained in field-caught cells (n = 20 species), and preferred food size based on prey size associated with maximal reported clearance rates (n = 15 species). Overall, LOD is closely related to most of the ecological parameters. Maximum growth rate is related to LOD with smaller LODs corresponding to higher growth rates, in contrast to LL and LV. Maximum prey size is positively related to both LOD and LL but more tightly with LOD. Preferred prey size is positively related to LOD and LV but more tightly related to LOD. Clearance rates of Acartia species feeding on tintinnids are significantly related only to LOD with small LODs corresponding to lower copepod feeding rates. Relationships excluding data on species of Tintinnopsis, the species-rich genus which generally dominates coastal communities, are also examined and show similar trends. In tintinnids, LOD, known to be a conservative and relatively reliable species characteristic, appears related to a wide range of ecological characteristics.
Iva Dyková, Martin Kostka, Hana Pecková
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 245-251
As a result of light microscopical, ultrastructural and molecular study of three amoeba strains isolated from organs of three freshwater fish hosts, Stenamoeba amazonica sp. n. and S. limacina sp. n. are described as new amoeba species. The mutual comparison of isolated strains has extended the knowledge of morphological diversity within the genus Stenamoeba Smirnov, Nassonova, Chao et Cavalier-Smith, 2007. Molecular data obtained for these strains have complemented the phylogenetic tree that so far has contained only one nominal species within the single-genus Stenamoeba clade.
Linda Basson
Acta Protozoologica, Volume 49, Issue 3, 2010, pp. 253-265
During parasitological surveys in Tasmania (Australia), four introduced fish species were investigated for the presence of trichodinid ectoparasites. Five trichodinid species were found on the skin, fins and gills of two of these fishes, i.e. the tench Tinca tinca Linnaeus, 1758 and the red fin perch Perca fluviatillis Linnaeus, 1758. Four trichodinids are known species for which comparative descriptions are provided, i.e. Trichodina acuta Lom, 1961, T. esocis Lom, 1961, T. lepsii Lom, 1962 and Trichodinella epizootica (Raabe 1950) Šrámek- Hušek, 1953. A fifth species, i.e. Trichodina tunnae sp. n. is described as a new species from the red fin perch. All species are described using silver impregnated and hematoxylin stained specimens.
Publication date: 2010
Editor-in-Chief: Krzysztof Wiąckowski
Wilhelm Foissner, Xinbai Shi, Ruiqing Wang, Alan Warren
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 87-105
We investigated the status of various Neokeronopsis populations, using protargol-impregnated type material, a new Chinese population, and literature data. This resulted not only in the recognition of a new species, Neokeronopsis asiatica, but also in upgrading Afrokeronopsis from subgenus to genus level. The genera Neokeronopsis and Afrokeronopsis differ mainly in the buccal depression (absent vs. present) and in the midventral cirri between proter and opisthe, which are either retained (Afrokeronopsis) or transformed into cirral anlagen (Neokeronopsis). Neokeronopsis asiatica nov. spec. differs from N. spectabilis (Kahl, 1932) by the following features: body size (~ 300 × 120 μm vs. 400 × 170 μm); posterior body end (acute with distinct indentation at site of caudal cirri vs. broadly rounded and without or indistinct indentation); posterior end of marginal rows (ending at different vs. same or similar level); dorsal kinety 1 (continuous vs. fragmented); and the size of the bases of the adoral membranelles (largest membranelles on average 18 μm vs. 29 μm wide). Improved diagnoses are provided for the family Neokeronopsidae and the genera contained therein, viz., Neokeronopsis, Afrokeronopsis, and Pattersoniella. Our study shows the importance of depositing type and voucher material in recognized repositories. Only this will allow future researchers to restudy the populations, for the sake of improved taxonomic and biogeographic knowledge.
Joy Ann G. Petronio, Windell L. Rivera
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 107-113
Paraphysomonas vestita is a unicellular, colorless, silica-scaled chrysophyte that plays an important ecological role in freshwater microbial communities as a consumer of prokaryotic and eukaryotic prey. There is little biogeographical information for this minute protist despite its significant role in aquatic food webs. In addition, the phylogenetic relationship of P. vestita to other taxa is unclear as P. vestita may be polyphyletic or a cryptic species complex. In this study, a clonal isolate from a freshwater sample of Laguna de Bay, Philippines was subjected to morphological study by electron microscopy and its small subunit ribosomal RNA (SSU rRNA) gene was sequenced. Morphological studies showed that the isolate possesses two unequal flagella emerging from the anterior part of the cell. Negative staining revealed the structure of the scales which consist of a baseplate with slightly thickened rim. The narrowing spine arises from the center of the baseplate. These results agree with previously studied isolates of P. vestita. The 18S rRNA gene sequence of the isolate had a very high similarity (99%) to P. vestita strain PV10. Phylogenetic analysis also showed that the isolate clustered with other Paraphysomonas sequences with high bootstrap support. Phylogenetic studies confirmed that P. vestita may be polyphyletic. No studies on the ultrastructure and phylogeny of a silica-scaled chrysophyte isolated in the Philippines have been reported so far. Results from this study may contribute to further ultrastructural and phylogenetic studies on aquatic flagellates and specifically to a revision of this potentially polyphyletic species.
Carlos Azevedo, Débora K. S. Marques, Graça Casal, Cristiane M. C. Amaral, Edinael V. Silva, Patrícia Matos, Edilson Rodrigues Matos
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 115-120
Ultrastructural analyses of fish-infecting myxosporean Henneguya piaractus that is found in the gill lamellae of the freshwater teleost Piaractus mesopotamicus (Characidae) and collected from the Paraguai River, Brazil were described. The parasite occurs within large whitish spherical to ellipsoidal polysporic cysts (up to 2.5 mm long) delimited by a layer of fibroblasts generally connected with some capillaries on the gill epithelium. No external morphological signs of disease were visible in the infected fishes. The tailed spores measured 61.5 ± 0.91 (60.2–62.6) μm in total length and ellipsoidal spore body 21.1 ± 0.62 (20.6–21.9) μm long, 6.7 ± 0.40 (6.2–7.3) μm wide and 2.5 ± 0.54 (2.0–3.1) μm thick. The spore wall was about 97 nm of thickness and consisted of a thin electron-dense exospore and a thick electron-lucent endospore with about 85 nm of thickness. The tailed spores were composed of two equal–sized shell valves adhering together along the straight suture line each having in continuity a equal caudal tapering tail measuring 40.5 ± 1.02 (38.7–43.1) μm in length. Two symmetric polar capsules measured 9.8 ± 0.28 (9.3–10.1) μm long and 1.9 ± 0.37 (1.4–2.4) μm wide, each having a polar filament with 10–11 (rarely 12) coils
Thomas E. McQuistion, Samuel Galewsky, Angelo P. Capparella, Fredrick Rebling
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 121-124
A new species of Isospora is described from the fecal contents of the white-chinned woodcreeper, Dendrocincla merula merula from Guyana and Dendrocincla merula barletti from Peru. Sporulated oocysts are subspherical to ovoid, 19.2 × 16.5 (15–23 × 14.5–19) μm, with a smooth, colorless, bilayered wall. The average shape index is 1.2. No micropyle or oocyst residuum are present, but the oocysts contain one polar granule. Sporocysts are ovoid, 12.9 × 8.3 (12–14 × 7–10) μm, average shape index of 1.7 with a smooth, single layered wall and composed of a small, knoblike Stieda body and a slightly larger, bubble shaped substieda body. The two sporocysts each contain a compact residuum composed of coarse, non-uniform granules and four randomly arranged, vermiform sporozoites each with a terminal refractile body and a centrally located nucleus. DNA sequences representing ITS-1 and ITS-4 regions of the 5.8S rDNA gene from the two isolates were amplified and compared. In addition to the two isolates showing similar morphological characteristics, they also had identical nucleotide sequences for the ITS-1 and ITS-4 regions of the 5.8S ribosomal gene.
Jaroslav Weiser, Peter Belton, Zdenek Zizka, Jaroslav Holusa
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 125-131
The type species of the genus Duboscqia Perez, 1908 (Opisthokonta, Microspora), D. legeri is a pathogen of termites. It was found again in Zootermopsis angusticollis in British Columbia and the material is used for emendation of data on ultrastructures of this old genus. The sporogony of this microsporidian ends with 16 oval spores closed in sporophorous vesicles. The isofilar polar filament coiled in 13 coils, the arched anchoring disc and the polaroplast with tightly packed lamellae are typical for the ultrastructures of uninucleate spores. The sporophorous vesicle is persistent. The microsporidian infects cyst-like lobes of the fat body hanging free in the body cavity. Relations to other related genera are discussed.
György Csaba, Eszter Lajkó, Éva Pállinger
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 133-138
Presence, uptake and production of serotonin and its effect on the production of other hormones were studied using immunocytochemical flow cytometric method. In a serotonin (10–12 M) containing medium up to 15 min. serotonin level does not elevate in the cells, but after 30 min. there is a significant elevation which remains till 4 h. In cells starved in salt solution the elevation is higher which calls attention to the effect of (starvation) stress. Using four enzyme blockers tryptophane hydroxylase inhibitor PCPA decreased (in serotonincontaining medium) and MAO B blocker deprenyl increased serotonin content, while serotonin reuptake inhibitor fluoxetine and MAO-A blocker clorgyline were ineffective. Extremely low concentrations of serotonin (10–15 M in case of histamine and 10–18 M in case of ACTH and T3) in the milieu was sufficient for increasing hormone (ACTH, T3, histamine) levels inside the cells. In conclusion; serotonin can be taken up by the cells and can be produced by induction, as Tetrahymena has enzymes for building it up and decomposing it. For synthesizing serotonin; basic molecules from outside are not needed. Serotonin in a minute amount can induce production of different hormones.
Micah Dunthorn, Jere H. Lipps, Thorsten Stoeck
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 139-144
Three putative ciliate fossils were described from the Neoproterozoic Doushantuo Formation in China: Eotintinnopsis, Wujiangella, and Yonyangella. The identity of these fossils is important for our understanding of the origins and early morphological evolution within ciliate clades. Here we compare the homology of the fossil characteristics with those in their proposed ciliate relatives. Eotintinnopsis resembles a tintinnid, but its feathery tentacle-like apical structure is probably not homologous within any known ciliate. Wujiangella presents homology issues with the size and distribution of its putative somatic cilia. Yonyangella appears to be a suctorian with its tentaclelike structures, but the presence and size of its putative somatic cilia pose homology issues. We suggest that these three fossils are likely to be taphonomically and diagenetically distorted and altered acritarchs. These alterations include secondary mineral encrustations on the interiors of vesicles, the crushing, folding and other distortions of the vesicles, the bending and crushing of the acritarch spines, and the preservation of organic material in and outside of the cysts. The earliest known ciliate fossil remains a tintinnid that occurs in the Ordovician of Kazakhstan.
Catherine Elizabeth Egan, Neil R. McEwan, Tim Snelling
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 145-147
The time of onset of survival of ciliate protozoa in the equine hindgut in new born foals was investigated. Daily faecal samples were collected from 6 new-born foals and studied under a microscope for examples of ciliates within the samples. The results of this study show that ciliates are first seen in faecal samples from the foal on day 5 post partum although these appeared to be voided and were assumed to be non-viable. However, by the following day the ciliates collected seen in the faecal samples appeared to be intact and were assumed to be viable. This observation is 5 days earlier than ciliates have previously been observed in faeces collected from the digestive tract of newborn foals.
Wilhelm Foissner, Xinbai Shi, Ruiqing Wang, Alan Warren
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 87-105
We investigated the status of various Neokeronopsis populations, using protargol-impregnated type material, a new Chinese population, and literature data. This resulted not only in the recognition of a new species, Neokeronopsis asiatica, but also in upgrading Afrokeronopsis from subgenus to genus level. The genera Neokeronopsis and Afrokeronopsis differ mainly in the buccal depression (absent vs. present) and in the midventral cirri between proter and opisthe, which are either retained (Afrokeronopsis) or transformed into cirral anlagen (Neokeronopsis). Neokeronopsis asiatica nov. spec. differs from N. spectabilis (Kahl, 1932) by the following features: body size (~ 300 × 120 μm vs. 400 × 170 μm); posterior body end (acute with distinct indentation at site of caudal cirri vs. broadly rounded and without or indistinct indentation); posterior end of marginal rows (ending at different vs. same or similar level); dorsal kinety 1 (continuous vs. fragmented); and the size of the bases of the adoral membranelles (largest membranelles on average 18 μm vs. 29 μm wide). Improved diagnoses are provided for the family Neokeronopsidae and the genera contained therein, viz., Neokeronopsis, Afrokeronopsis, and Pattersoniella. Our study shows the importance of depositing type and voucher material in recognized repositories. Only this will allow future researchers to restudy the populations, for the sake of improved taxonomic and biogeographic knowledge.
Joy Ann G. Petronio, Windell L. Rivera
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 107-113
Paraphysomonas vestita is a unicellular, colorless, silica-scaled chrysophyte that plays an important ecological role in freshwater microbial communities as a consumer of prokaryotic and eukaryotic prey. There is little biogeographical information for this minute protist despite its significant role in aquatic food webs. In addition, the phylogenetic relationship of P. vestita to other taxa is unclear as P. vestita may be polyphyletic or a cryptic species complex. In this study, a clonal isolate from a freshwater sample of Laguna de Bay, Philippines was subjected to morphological study by electron microscopy and its small subunit ribosomal RNA (SSU rRNA) gene was sequenced. Morphological studies showed that the isolate possesses two unequal flagella emerging from the anterior part of the cell. Negative staining revealed the structure of the scales which consist of a baseplate with slightly thickened rim. The narrowing spine arises from the center of the baseplate. These results agree with previously studied isolates of P. vestita. The 18S rRNA gene sequence of the isolate had a very high similarity (99%) to P. vestita strain PV10. Phylogenetic analysis also showed that the isolate clustered with other Paraphysomonas sequences with high bootstrap support. Phylogenetic studies confirmed that P. vestita may be polyphyletic. No studies on the ultrastructure and phylogeny of a silica-scaled chrysophyte isolated in the Philippines have been reported so far. Results from this study may contribute to further ultrastructural and phylogenetic studies on aquatic flagellates and specifically to a revision of this potentially polyphyletic species.
Carlos Azevedo, Débora K. S. Marques, Graça Casal, Cristiane M. C. Amaral, Edinael V. Silva, Patrícia Matos, Edilson Rodrigues Matos
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 115-120
Ultrastructural analyses of fish-infecting myxosporean Henneguya piaractus that is found in the gill lamellae of the freshwater teleost Piaractus mesopotamicus (Characidae) and collected from the Paraguai River, Brazil were described. The parasite occurs within large whitish spherical to ellipsoidal polysporic cysts (up to 2.5 mm long) delimited by a layer of fibroblasts generally connected with some capillaries on the gill epithelium. No external morphological signs of disease were visible in the infected fishes. The tailed spores measured 61.5 ± 0.91 (60.2–62.6) μm in total length and ellipsoidal spore body 21.1 ± 0.62 (20.6–21.9) μm long, 6.7 ± 0.40 (6.2–7.3) μm wide and 2.5 ± 0.54 (2.0–3.1) μm thick. The spore wall was about 97 nm of thickness and consisted of a thin electron-dense exospore and a thick electron-lucent endospore with about 85 nm of thickness. The tailed spores were composed of two equal–sized shell valves adhering together along the straight suture line each having in continuity a equal caudal tapering tail measuring 40.5 ± 1.02 (38.7–43.1) μm in length. Two symmetric polar capsules measured 9.8 ± 0.28 (9.3–10.1) μm long and 1.9 ± 0.37 (1.4–2.4) μm wide, each having a polar filament with 10–11 (rarely 12) coils
Thomas E. McQuistion, Samuel Galewsky, Angelo P. Capparella, Fredrick Rebling
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 121-124
A new species of Isospora is described from the fecal contents of the white-chinned woodcreeper, Dendrocincla merula merula from Guyana and Dendrocincla merula barletti from Peru. Sporulated oocysts are subspherical to ovoid, 19.2 × 16.5 (15–23 × 14.5–19) μm, with a smooth, colorless, bilayered wall. The average shape index is 1.2. No micropyle or oocyst residuum are present, but the oocysts contain one polar granule. Sporocysts are ovoid, 12.9 × 8.3 (12–14 × 7–10) μm, average shape index of 1.7 with a smooth, single layered wall and composed of a small, knoblike Stieda body and a slightly larger, bubble shaped substieda body. The two sporocysts each contain a compact residuum composed of coarse, non-uniform granules and four randomly arranged, vermiform sporozoites each with a terminal refractile body and a centrally located nucleus. DNA sequences representing ITS-1 and ITS-4 regions of the 5.8S rDNA gene from the two isolates were amplified and compared. In addition to the two isolates showing similar morphological characteristics, they also had identical nucleotide sequences for the ITS-1 and ITS-4 regions of the 5.8S ribosomal gene.
Jaroslav Weiser, Peter Belton, Zdenek Zizka, Jaroslav Holusa
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 125-131
The type species of the genus Duboscqia Perez, 1908 (Opisthokonta, Microspora), D. legeri is a pathogen of termites. It was found again in Zootermopsis angusticollis in British Columbia and the material is used for emendation of data on ultrastructures of this old genus. The sporogony of this microsporidian ends with 16 oval spores closed in sporophorous vesicles. The isofilar polar filament coiled in 13 coils, the arched anchoring disc and the polaroplast with tightly packed lamellae are typical for the ultrastructures of uninucleate spores. The sporophorous vesicle is persistent. The microsporidian infects cyst-like lobes of the fat body hanging free in the body cavity. Relations to other related genera are discussed.
György Csaba, Eszter Lajkó, Éva Pállinger
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 133-138
Presence, uptake and production of serotonin and its effect on the production of other hormones were studied using immunocytochemical flow cytometric method. In a serotonin (10–12 M) containing medium up to 15 min. serotonin level does not elevate in the cells, but after 30 min. there is a significant elevation which remains till 4 h. In cells starved in salt solution the elevation is higher which calls attention to the effect of (starvation) stress. Using four enzyme blockers tryptophane hydroxylase inhibitor PCPA decreased (in serotonincontaining medium) and MAO B blocker deprenyl increased serotonin content, while serotonin reuptake inhibitor fluoxetine and MAO-A blocker clorgyline were ineffective. Extremely low concentrations of serotonin (10–15 M in case of histamine and 10–18 M in case of ACTH and T3) in the milieu was sufficient for increasing hormone (ACTH, T3, histamine) levels inside the cells. In conclusion; serotonin can be taken up by the cells and can be produced by induction, as Tetrahymena has enzymes for building it up and decomposing it. For synthesizing serotonin; basic molecules from outside are not needed. Serotonin in a minute amount can induce production of different hormones.
Micah Dunthorn, Jere H. Lipps, Thorsten Stoeck
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 139-144
Three putative ciliate fossils were described from the Neoproterozoic Doushantuo Formation in China: Eotintinnopsis, Wujiangella, and Yonyangella. The identity of these fossils is important for our understanding of the origins and early morphological evolution within ciliate clades. Here we compare the homology of the fossil characteristics with those in their proposed ciliate relatives. Eotintinnopsis resembles a tintinnid, but its feathery tentacle-like apical structure is probably not homologous within any known ciliate. Wujiangella presents homology issues with the size and distribution of its putative somatic cilia. Yonyangella appears to be a suctorian with its tentaclelike structures, but the presence and size of its putative somatic cilia pose homology issues. We suggest that these three fossils are likely to be taphonomically and diagenetically distorted and altered acritarchs. These alterations include secondary mineral encrustations on the interiors of vesicles, the crushing, folding and other distortions of the vesicles, the bending and crushing of the acritarch spines, and the preservation of organic material in and outside of the cysts. The earliest known ciliate fossil remains a tintinnid that occurs in the Ordovician of Kazakhstan.
Catherine Elizabeth Egan, Neil R. McEwan, Tim Snelling
Acta Protozoologica, Volume 49, Issue 2, 2010, pp. 145-147
The time of onset of survival of ciliate protozoa in the equine hindgut in new born foals was investigated. Daily faecal samples were collected from 6 new-born foals and studied under a microscope for examples of ciliates within the samples. The results of this study show that ciliates are first seen in faecal samples from the foal on day 5 post partum although these appeared to be voided and were assumed to be non-viable. However, by the following day the ciliates collected seen in the faecal samples appeared to be intact and were assumed to be viable. This observation is 5 days earlier than ciliates have previously been observed in faeces collected from the digestive tract of newborn foals.
Publication date: 2010
Editor-in-Chief: Krzysztof Wiąckowski
O. Roger Anderson
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 1-8
Naked amoebae are among the most abundant soil protists, especially in highly productive soils. Their capacity to produce cysts during unfavorable growth periods, especially drying, enhances their survivability as resting stages and promotes dispersal by wind and air currents. However, the dynamics of their cycles of encystment and active growth are poorly documented. Using a recently developed culture observation method, including a dried preparation stage to detect encysted amoebae, data are presented on the ratios of active and encysted stages of naked amoebae based on field samples from diverse terrestrial sites differing in plant cover and moisture content during spring and summer months 2008 at a location in northeastern U.S.A. Percentage of encysted amoebae varied between 32% and 100% depending on locale and moisture content. Carbon content of the cysts (estimated from recently excysted individuals) relative to trophic stages varied between 22% and 100% at these same locales. Laboratory experimental studies of winter soil samples, that were cultured at 25oC to promote amoeba community growth, indicated that a dynamic relationship exists between active and encysted stages during proliferation with varying ratios depending on the moisture content and qualities of the soil at the collection site, thus suggesting a revised model as presented here of the encystment-excystment cycle for populations during a growth succession.
David Modrý
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 1-1
The Biology of the Coccidia (Apicomplexa) of Snakes of the World: A Scholarly Handbook for Identification and Treatment, Donald W. Duszynski and Steve J. Upton, 430 pages, Illustrated. CreateSpace Inc., a DBA of On-Demand publishing LLC, an Amazon.com Company, Price $70.00 USD (https://createspace.com/3388533). ISBN: 1448617995.
Wendy Trzyna, Margaret W. Mbugua, Andrew Rogerson
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 9-15
The aim of this study was to determine the prevalence of Acanthamoeba in the domestic water supply in Huntington, West Virginia (U.S.A.) and the factors that may contribute to their presence or absence. One hundred sixty-two one liter tap water samples were collected over eight months. Amoebae in the samples (cysts or trophozoites) were harvested by passively filtering onto 5 μm pore size filters and enriching for amoebae on non-nutrient amoeba saline agar plates seeded with Escherichia coli for cultivation. Thirteen percent of all samples were positive for amoebae and 9.3% were positive for the amoeba of interest, Acanthamoeba. Chlorine levels were determined for samples at the time of collection, yielding a mean level of 1.56 mg l–1 chlorine in the distribution system ca. 8 kilometers from the water treatment plant. Cysts and trophozoites of Acanthamoeba clonal isolates were found to tolerate up to 50 mg l–1 and 4 mg l–1 chlorine respectively. This study showed that Acanthamoeba were present in the domestic water supply in Huntington, WV and although no attempt was made to count cells in liter samples, their frequency of occurrence (9.3%) and failure to be present in all replicates, suggests they were present at background levels of perhaps a few cells per five liters. This is only the second U.S. study to consider amoebae in tap water and is unique since the source water was river water. Acanthamoeba trophozoites and cysts were able to withstand levels of chlorine higher than those typically found in tap water suggesting they may be present in either form in the distribution system. Acanthamoeba are opportunistic pathogens capable of causing eye infections and their presence in tap water is a potential risk factor for susceptible individuals, particularly contact lens wearers who may use tap water to clean lenses and storage cases.
Valentyna Krashevska, Mark Maraun, Stefan Scheu
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 17-28
We investigated changes in diversity and density of testate amoebae in epiphytes of trees in tropical montane rain forests of southern Ecuador. Local – microscale [height on tree trunk of 0 (base of tree trunk), 1 and 2 m; TH I, TH II and TH III, respectively] and regional – macroscale (forests at 1000, 2000 and 3000 m) changes were investigated. At the macroscale diversity and density of testate amoebae peaked at 2000 m. At the microscale diversity reached a maximum at TH I, whereas density reached a maximum at TH III. The percentage of empty shells at the macroscale was at a maximum at 2000 m and at the microscale at TH I, whereas the percentage of live cells was at a maximum at 3000 m and at TH III. The diversity of testate amoebae in epiphytes found in the present study was high (113 species). However, only two to nine species were dominant representing 54–85 percent of total living testate amoebae. The results suggest significant variations in density and diversity of testate amoebae at both the micro- and macroscale. However, for testate amoebae density the macroscale appears most important whereas changes in diversity are more pronounced at the microscale
Robert K. Booth, Blaze Meyers
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 29-35
Testate amoebae are routinely used as paleoenvironmental indicators. However, considerable variability occurs in test morphology, even within commonly identified taxa. Relationships between morphological variability and environmental conditions might be useful in paleohydrological studies of peatlands, assuming good preservation of characteristics. Hyalosphenia papilio is a common taxon, well preserved in Sphagnum peatlands, that displays variability in the number of pores on the broad side of the test. We assessed whether variability in pore number was related to substrate moisture by comparing the abundance of individuals with different numbers of pores to measured water-table depths at 67 sites in North America. Results indicated that the abundance of individuals with higher numbers of pores increased in wetter conditions. Individuals with 2 pores were relatively widespread, although they dominated drier habitats. Transfer functions developed with and without pore-number quantification suggest that when communities contain abundant individuals with greater than 2 pores, water-table depth reconstructions can be improved by including pore-number information. Results have implications for peatland paleohydrological studies and suggest that greater exploitation of morphological variability could improve testate amoeba-based reconstructions of past environmental change.
Milcho Todorov
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 37-43
A new sphagnicolous species of the genus Nebela isolated from wet Sphagnum mosses gathered at Vitosha Mountain (Bulgaria) is described. Shell ultrastructure and morphological variability of Nebela golemanskyi sp. nov. are investigated using scanning electron microscopy. The newly described species is characterized by its almost uncompressed shell and by its large, rounded, voluminous and hollow structural elements (idiosomes). The analysis of the variation coefficients shows that the studied population is too homogeneous and all measured morphological characters are feebly variable (CV range from 3.28% to 5.02%). Size frequency distribution analysis indicates that N. golemanskyi is size-polymorphic species, characterized by not well-expressed main-size class in favour of many subsidiary classes. A biometrical and morphological comparison between N. golemanskyi and N. speciosa is made.
Hongbo Pan, Jie Huang, Xiaozhong Hu, Xinpeng Fan, Khaled A. S. Al-Rasheid, Weibo Song
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 45-59
The morphology, infraciliature, and silverline system of three marine scuticociliates, Uronema marinum Dujardin, 1841, U. heteromarinum nov. spec. and Pleuronema setigerum Calkins, 1902, isolated from coastal waters off Qingdao, China, were investigated using living observation and silver impregnation methods. Due to the great confusion in the species definition of the well-known species U. marinum, we have documented a detailed discussion/comparison and believe that most of the confusion is due to the fact that at least 2 closely-related sibling morphotypes exist which are often not recognized. Based on the data available, U. marinum is strictly defined as follows: marine Uronema ca. 30 × 10 μm in size, with truncated apical frontal plate and smooth pellicle, extrusomes inconspicuous, cytostome located equatorially, 12–14 somatic kineties and one contractile vacuole pore near posterior end of kinety 2. Uronema heteromarinum nov. spec. resembles U. marinum but can be distinguished morphologically by its notched pellicle with conspicuous extrusomes and reticulate ridges, the 15–16 somatic kineties, widely separated membranelle 1 and membranelle 2, as well as the subequatorially positioned cytostome. Based on the Qingdao population, an improved diagnosis for the poorly known Pleuronema setigerum is: marine slender oval-shaped form, in vivo about 40–50 × 15–20 μm; 3–5 preoral kineties and 14–22 somatic kineties; membranelle 1 and 3 three-rowed, and posterior end of M2a ring-like. The small subunit (SSU) rRNA gene for all three organisms were sequenced and analyzed with standard methods.
Helene Peters, Liesl L. van As, Linda Basson
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 61-74
Mantoscyphidians occur in high numbers on the gills of South African Haliotis and limpet species. This provided the ideal opportunity to study asexual and sexual reproduction, for the first time in different African Mantoscyphidia Jankowski, 1985 populations. Descriptions of the reproductive processes found in scyphidiid peritrichs were until now, mostly based on line drawings. Scanning electronand light microscopy contributed uniquely, in providing detail information regarding binary fission, telotroch formation and conjugation. Mantoscyphidia spadiceae Botes, Basson and Van As, 2001 shed the most light on binary fission. Micronuclear division occurred first with the plane of fission already evident and macronuclear cleavage ended just before final separation took place. Fission is not complete until a small string of pellicle that joins the daughter cells finally separates. Information on telotroch development was gathered from M. branchi Van As, Basson and Van As, 1998 and M. spadiceae populations. Telotrochs were between 36.7 and 38.6% shorter than live, extended mantoscyphidians and their swimming action resembled mobiline peritrichs. Mantoscyphidia branchi populations also proved to be most useful for conjugation studies. Conjugation included three progamic nuclear divisions and preceded synkaryon formation and two metagamic nuclear divisions. The process required 24 hours to be completed.
Irma V. Issi, Yuri S. Tokarev, Vladimir N. Voronin, Elena V. Seliverstova, Olga A. Pavlova, Vyacheslav V. Dolgikh
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 75-84
The ultrastructure and molecular phylogeny of a new microsporidium Mrazekia macrocyclopis sp.n., a parasite of the copepod Macrocyclops albidus (Jur.) in North-West of Russia are described. All stages of its life cycle are diplokaryotic. Fresh spores are rod-shaped and 7.3–10.5 × 1.6–2.3 μm in size. Spore ultrastructure is typical of Mrazekia. The polar tube consists of the anterior clavate manubrium followed by a thin filament arranged in 3.5–4.5 nearly vertical coils. Spores are enclosed in individual sporophorous vesicles. SSU rDNA sequence analysis showed attribution of the new species to a cluster of microsporidia infecting insects (Cystosporogenes, Endoreticulatus), microsrustaceans (Glugoides), vertebrates (Vittaforma) and ciliates (Euplotespora) nested within the clade IV sensu Vossbrinck, Debrunner- Vossbrinck (2005). Mrazekia macrocyclopis is not therefore closely related to Bacillidium vesiculoformis, another microsporidium with rod-shaped spores, and the polyphyletic nature of the family of Mrazekiidae is obvious.
O. Roger Anderson
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 1-8
Naked amoebae are among the most abundant soil protists, especially in highly productive soils. Their capacity to produce cysts during unfavorable growth periods, especially drying, enhances their survivability as resting stages and promotes dispersal by wind and air currents. However, the dynamics of their cycles of encystment and active growth are poorly documented. Using a recently developed culture observation method, including a dried preparation stage to detect encysted amoebae, data are presented on the ratios of active and encysted stages of naked amoebae based on field samples from diverse terrestrial sites differing in plant cover and moisture content during spring and summer months 2008 at a location in northeastern U.S.A. Percentage of encysted amoebae varied between 32% and 100% depending on locale and moisture content. Carbon content of the cysts (estimated from recently excysted individuals) relative to trophic stages varied between 22% and 100% at these same locales. Laboratory experimental studies of winter soil samples, that were cultured at 25oC to promote amoeba community growth, indicated that a dynamic relationship exists between active and encysted stages during proliferation with varying ratios depending on the moisture content and qualities of the soil at the collection site, thus suggesting a revised model as presented here of the encystment-excystment cycle for populations during a growth succession.
David Modrý
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 1-1
The Biology of the Coccidia (Apicomplexa) of Snakes of the World: A Scholarly Handbook for Identification and Treatment, Donald W. Duszynski and Steve J. Upton, 430 pages, Illustrated. CreateSpace Inc., a DBA of On-Demand publishing LLC, an Amazon.com Company, Price $70.00 USD (https://createspace.com/3388533). ISBN: 1448617995.
Wendy Trzyna, Margaret W. Mbugua, Andrew Rogerson
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 9-15
The aim of this study was to determine the prevalence of Acanthamoeba in the domestic water supply in Huntington, West Virginia (U.S.A.) and the factors that may contribute to their presence or absence. One hundred sixty-two one liter tap water samples were collected over eight months. Amoebae in the samples (cysts or trophozoites) were harvested by passively filtering onto 5 μm pore size filters and enriching for amoebae on non-nutrient amoeba saline agar plates seeded with Escherichia coli for cultivation. Thirteen percent of all samples were positive for amoebae and 9.3% were positive for the amoeba of interest, Acanthamoeba. Chlorine levels were determined for samples at the time of collection, yielding a mean level of 1.56 mg l–1 chlorine in the distribution system ca. 8 kilometers from the water treatment plant. Cysts and trophozoites of Acanthamoeba clonal isolates were found to tolerate up to 50 mg l–1 and 4 mg l–1 chlorine respectively. This study showed that Acanthamoeba were present in the domestic water supply in Huntington, WV and although no attempt was made to count cells in liter samples, their frequency of occurrence (9.3%) and failure to be present in all replicates, suggests they were present at background levels of perhaps a few cells per five liters. This is only the second U.S. study to consider amoebae in tap water and is unique since the source water was river water. Acanthamoeba trophozoites and cysts were able to withstand levels of chlorine higher than those typically found in tap water suggesting they may be present in either form in the distribution system. Acanthamoeba are opportunistic pathogens capable of causing eye infections and their presence in tap water is a potential risk factor for susceptible individuals, particularly contact lens wearers who may use tap water to clean lenses and storage cases.
Valentyna Krashevska, Mark Maraun, Stefan Scheu
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 17-28
We investigated changes in diversity and density of testate amoebae in epiphytes of trees in tropical montane rain forests of southern Ecuador. Local – microscale [height on tree trunk of 0 (base of tree trunk), 1 and 2 m; TH I, TH II and TH III, respectively] and regional – macroscale (forests at 1000, 2000 and 3000 m) changes were investigated. At the macroscale diversity and density of testate amoebae peaked at 2000 m. At the microscale diversity reached a maximum at TH I, whereas density reached a maximum at TH III. The percentage of empty shells at the macroscale was at a maximum at 2000 m and at the microscale at TH I, whereas the percentage of live cells was at a maximum at 3000 m and at TH III. The diversity of testate amoebae in epiphytes found in the present study was high (113 species). However, only two to nine species were dominant representing 54–85 percent of total living testate amoebae. The results suggest significant variations in density and diversity of testate amoebae at both the micro- and macroscale. However, for testate amoebae density the macroscale appears most important whereas changes in diversity are more pronounced at the microscale
Robert K. Booth, Blaze Meyers
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 29-35
Testate amoebae are routinely used as paleoenvironmental indicators. However, considerable variability occurs in test morphology, even within commonly identified taxa. Relationships between morphological variability and environmental conditions might be useful in paleohydrological studies of peatlands, assuming good preservation of characteristics. Hyalosphenia papilio is a common taxon, well preserved in Sphagnum peatlands, that displays variability in the number of pores on the broad side of the test. We assessed whether variability in pore number was related to substrate moisture by comparing the abundance of individuals with different numbers of pores to measured water-table depths at 67 sites in North America. Results indicated that the abundance of individuals with higher numbers of pores increased in wetter conditions. Individuals with 2 pores were relatively widespread, although they dominated drier habitats. Transfer functions developed with and without pore-number quantification suggest that when communities contain abundant individuals with greater than 2 pores, water-table depth reconstructions can be improved by including pore-number information. Results have implications for peatland paleohydrological studies and suggest that greater exploitation of morphological variability could improve testate amoeba-based reconstructions of past environmental change.
Milcho Todorov
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 37-43
A new sphagnicolous species of the genus Nebela isolated from wet Sphagnum mosses gathered at Vitosha Mountain (Bulgaria) is described. Shell ultrastructure and morphological variability of Nebela golemanskyi sp. nov. are investigated using scanning electron microscopy. The newly described species is characterized by its almost uncompressed shell and by its large, rounded, voluminous and hollow structural elements (idiosomes). The analysis of the variation coefficients shows that the studied population is too homogeneous and all measured morphological characters are feebly variable (CV range from 3.28% to 5.02%). Size frequency distribution analysis indicates that N. golemanskyi is size-polymorphic species, characterized by not well-expressed main-size class in favour of many subsidiary classes. A biometrical and morphological comparison between N. golemanskyi and N. speciosa is made.
Hongbo Pan, Jie Huang, Xiaozhong Hu, Xinpeng Fan, Khaled A. S. Al-Rasheid, Weibo Song
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 45-59
The morphology, infraciliature, and silverline system of three marine scuticociliates, Uronema marinum Dujardin, 1841, U. heteromarinum nov. spec. and Pleuronema setigerum Calkins, 1902, isolated from coastal waters off Qingdao, China, were investigated using living observation and silver impregnation methods. Due to the great confusion in the species definition of the well-known species U. marinum, we have documented a detailed discussion/comparison and believe that most of the confusion is due to the fact that at least 2 closely-related sibling morphotypes exist which are often not recognized. Based on the data available, U. marinum is strictly defined as follows: marine Uronema ca. 30 × 10 μm in size, with truncated apical frontal plate and smooth pellicle, extrusomes inconspicuous, cytostome located equatorially, 12–14 somatic kineties and one contractile vacuole pore near posterior end of kinety 2. Uronema heteromarinum nov. spec. resembles U. marinum but can be distinguished morphologically by its notched pellicle with conspicuous extrusomes and reticulate ridges, the 15–16 somatic kineties, widely separated membranelle 1 and membranelle 2, as well as the subequatorially positioned cytostome. Based on the Qingdao population, an improved diagnosis for the poorly known Pleuronema setigerum is: marine slender oval-shaped form, in vivo about 40–50 × 15–20 μm; 3–5 preoral kineties and 14–22 somatic kineties; membranelle 1 and 3 three-rowed, and posterior end of M2a ring-like. The small subunit (SSU) rRNA gene for all three organisms were sequenced and analyzed with standard methods.
Helene Peters, Liesl L. van As, Linda Basson
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 61-74
Mantoscyphidians occur in high numbers on the gills of South African Haliotis and limpet species. This provided the ideal opportunity to study asexual and sexual reproduction, for the first time in different African Mantoscyphidia Jankowski, 1985 populations. Descriptions of the reproductive processes found in scyphidiid peritrichs were until now, mostly based on line drawings. Scanning electronand light microscopy contributed uniquely, in providing detail information regarding binary fission, telotroch formation and conjugation. Mantoscyphidia spadiceae Botes, Basson and Van As, 2001 shed the most light on binary fission. Micronuclear division occurred first with the plane of fission already evident and macronuclear cleavage ended just before final separation took place. Fission is not complete until a small string of pellicle that joins the daughter cells finally separates. Information on telotroch development was gathered from M. branchi Van As, Basson and Van As, 1998 and M. spadiceae populations. Telotrochs were between 36.7 and 38.6% shorter than live, extended mantoscyphidians and their swimming action resembled mobiline peritrichs. Mantoscyphidia branchi populations also proved to be most useful for conjugation studies. Conjugation included three progamic nuclear divisions and preceded synkaryon formation and two metagamic nuclear divisions. The process required 24 hours to be completed.
Irma V. Issi, Yuri S. Tokarev, Vladimir N. Voronin, Elena V. Seliverstova, Olga A. Pavlova, Vyacheslav V. Dolgikh
Acta Protozoologica, Volume 49, Issue 1 , 2010, pp. 75-84
The ultrastructure and molecular phylogeny of a new microsporidium Mrazekia macrocyclopis sp.n., a parasite of the copepod Macrocyclops albidus (Jur.) in North-West of Russia are described. All stages of its life cycle are diplokaryotic. Fresh spores are rod-shaped and 7.3–10.5 × 1.6–2.3 μm in size. Spore ultrastructure is typical of Mrazekia. The polar tube consists of the anterior clavate manubrium followed by a thin filament arranged in 3.5–4.5 nearly vertical coils. Spores are enclosed in individual sporophorous vesicles. SSU rDNA sequence analysis showed attribution of the new species to a cluster of microsporidia infecting insects (Cystosporogenes, Endoreticulatus), microsrustaceans (Glugoides), vertebrates (Vittaforma) and ciliates (Euplotespora) nested within the clade IV sensu Vossbrinck, Debrunner- Vossbrinck (2005). Mrazekia macrocyclopis is not therefore closely related to Bacillidium vesiculoformis, another microsporidium with rod-shaped spores, and the polyphyletic nature of the family of Mrazekiidae is obvious.
Publication date: 2009
Editor-in-Chief: Krzysztof Wiąckowski
Alexander Kudryavtsev, Klaus Hausmann
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 91-96
Thecamoeba aesculea n. sp. was isolated and described from the surface of the bark of Aesculus hippocastanum and from terrestrial mosses growing on it. This amoeba is superficially similar to Thecamoeba sphaeronucleolus, but comparison of the newly isolated strain with the photographs and video records of the type strain of this species reveals differences which show that the two strains do not belong to the same morphospecies. The data obtained indicate the necessity of further comparative studies on the diversity of thecamoebian ‘morphospecies’ to outline clearer borders between them.
Áron Keve Kiss, Júlia Katalin Török, Éva Ács, Keve Tihamér Kiss
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 97-110
Three new, minute testate amoeban species smaller than 15 μm, including one new genus, are described from the plankton of the River Danube (Hungary) using high resolution video micrography. Pseudodifflugia klarae nov. spec. is characterised by an oval/pyriform, rigid, slightly compressed, scarcely or densely agglutinated test with a length of 8–14 μm. Its aperture is irregular in outline and inconspicuous; the nucleus contains one nucleolus and a few bent rods in the nucleoplasm. Bereczkya nov. gen., an incertae sedis cercozoan, has a minute spherical cell enclosed in a thin, rigid, more or less agglutinated organic test that is filled entirely by the cytoplasm. Its test bears an irregular and inconspicuous aperture. A collar-like ectoplasmic rim is situated in the aperture, from which a pseudopodial stem with filopodia is erected. The nucleus is slightly irregular, without a central nucleolus, but it contains rod-shaped granules in the nucleoplasm. Bereczkya minuta nov. spec. (test length: 3.5–8 μm, the diameter of the ectoplasmic rim: 0.8–2.3 μm) has a spherical test with asymmetric swellings and depressions, agglutinated with refractile mineral and other flat or irregularly-shaped xenosomes that may sometimes be almost entirely absent. Paramphitrema muelleri nov. spec. has a tubular or lemon-like test (length: 13–17 μm), which tapers towards the rigid apertures. The test is rigid, agglutinated and ism circular in cross section. The nucleus is vesicular. Thin filopodia, as well as 1–2 thick, straight, unbranched, tubular pseudopodia are produced.
Martin Mrva
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 111-117
Lieberkuehnia wageneri Claparède et Lachmann, 1859, a poorly known freshwater foraminiferan, was re-discovered after 38 years in a moss sample from an oak-hornbeam forest in Malé Karpaty Mts. (Western Slovakia). The species was taxonomically revised, re-described using light microscopical observations, and its occurrence and ecology were reviewed. Its locomotive form is typical with membranous and flexible ovoid test having a single terminal aperture from which a broad pseudopodial network emerges on a pseudopodial peduncle. Additional data and details are described, illustrated and discussed. Lieberkuehnia wageneri is known from various freshwater, soil and marine habitats in Western and Middle Europe, suggesting a high ecological tolerance and wide distribution. It is hoped that the observations reported in this paper will aid the identification of this species based on the locomotive morphology at the light microscopical level.
Willem H. De Smet
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 119-126
A new testate amoeba Scutiglypha cabrolae sp. n. is described from a small lake located in the caldera of Licancabur volcano, central Andes, at 5916 m above sea level. Its morphology was investigated using light and scanning electron microscopy. The main characteristics of the new species are: thick-set ovate test, length/width ratio 1.4; relatively small size, mean length × width: 69 × 48 μm; 3–4 rows of apertural plates, apertural plates of first row lozenge-shaped, oral margin with median tooth and (5)–6 lateral toothlets; body-plates scutiform, broad, with weakly crenulated oral and aboral margin.
Daniel J. G. Lahr, Sônia G. B. C. Lopes
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 127-142
The taxonomic identity in microbial eukaryotes remains an impediment to discussing ecology, biogeography and phylogeny, mainly due to a lack of standards in organism descriptions and few comparative works. The lobose testate amoebae (Arcellinida) present an ideal study system, as progress is severely hindered due to taxonomic confusion. In the present survey, we have examined the morphology, biometry and ecology of 2400 individuals in the genus Arcella Ehrenberg, 1832, collected from the Tiete River in Sao Paulo, Brazil. We then contrasted these new data with 26 previously described species, varieties and forms, looking for consistencies and trying to establish distinct entities. Using a combination of morphology and multivariate statistics we were able to determine 4 distinct taxa (Arcella hemisphaerica, Arcella discoides, Arcella gibbosa and Arcella brasiliensis), each of them encompassing a number of other non-distinct nominal taxa. We describe in detail each of the 4 taxa with notes on ecology and biogeography, and list the indistinguishable names in an effort to make identification and taxonomy in the testate amoebae a more objective and precise exercise by clarifying the taxonomic identity.
Milcho Todorov
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 143-151
Shell ultra-structure and morphometrical variability of Nebela tenella were investigated using scanning electron microscopy (SEM). N. tenella was isolated from two widely separated populations, one from Switzerland and another from Canada. The shell’s structural elements were similar to those of the other nebelids, but N. tenella has a characteristic peculiarity – always present depressions on the shell surface, which makes an uneven outline of the shell. Moreover, light microscopy and SEM study showed that the collar of the N. tenella represents a turned-over continuation of the neck, which is covered by the same idiosomes as on the shell body. The biometrical analysis showed that the majority of the basic characters of N. tenella vary moderately and give continuous series of transition forms. According to the shell depth and the ratio depth/width both populations were significantly different of each other. Variation coefficients showed that the variability of the characters differs in both populations and the Swiss population is more stable than the Canadian one. All new obtained data for N. tenella raise the question whether the shell’s size, cross section and ultramorphology are reliable enough as characters for the differentiation of N. tenella and N. griseola, and whether they are two distinct species or should just be considered as ecophenotypic variation within one species?
Nicolas P. Dolapsakis, Athena Economou-Amilli
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 153-170
Genus Amphidinium Claparède et Lachmann (Gymnodiniales, Dinophyceae) sensu lato has recently undergone a reappraisal using extended microscopical methods and genetic comparisons, with the type species and morphologically similar species used for the redescription of the genus Amphidinium sensu stricto. Within the latter concept of the genus, the new species Amphidinium thermaeum is established using light and scanning electron microscopy in combination with LSU rDNA phylogeny. This species was isolated from the Thermaikos Gulf in Greece, and its description is largely based on observations of cultured material. The main diacritic features distinguishing A. thermaeum from related taxa were: shape, size and plasticity of the cell, position of distal and proximal cingulum ends, site of longitudinal flagellar insertion, sulcal course, pusule details, plastid characteristics, and mode of cell division. Genetic phylogeny applying Bayesian Inference, Maximum Likelihood, and Neighbor-Joining analyses, places A. thermaeum in an independent position within the Amphidinium sensu stricto monophyletic group, and the new species is closely related to its small and morphologically similar siblings (A. massartii, A. klebsii, A. trulla, A. gibbosum, A. carterae).
Daode Ji, Joong Ki Choi, Alan Warren, Weibo Song, Henglong Xu
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 171-183
Three marine peritrichous ciliates, Zoothamnium alrasheidi spec. nov., Z. marinum Kahl, 1933 and Z. vermicola Precht, 1935, were isolated from littoral areas near Qingdao, China. The living morphology, infraciliature and silverline system were studied in living and silver-impregnated specimens. Zoothamnium alrasheidi is distinguished from its congeners by the giant, leaf-shaped colony, the differentiation of zooids, the structure of the infundibular polykineties and in having 57–75 silverlines between the oral area and the trochal band and 24–42 between the trochal band and the scopula. Zoothamnium marinum and Z. vermicola are reported for the first time in over 70 years. Each was identified by its zooid shape and size, colony shape, the branching pattern of its stalk and its marine habitat. As a result of the present study, additional features for characterizing these species now include the structure of infundibular polykinety 3 and the number of silverlines between the aboral trochal band and (a) the scopula, and (b) the peristomial lip. Redescriptions and improved diagnoses of both species are supplied based on the Chinese populations.
Mohamad Ahmad Ali
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 185-190
Ortholinea africanus Abdel-Ghaffar et al., 2008 is re-described using light and scanning electron microscopy (SEM) to reveal the external ornamentation of the spores. Present spores matched the original description in morphology but were larger in all dimensions. They measured 9.6 ± 0.8 (8.1–10.9) μm in length, 9.5 ± 0.6 (8.8–10.9) μm in width and 8.9 ± 0.4 (8.6–9.1) μm in thickness. Polar capsules were 3.9 ± 0.3 (3.0–4.3) μm in length with polar filaments turned 4–6 turns. The pattern of polar filament coils was different in each of the polar capsules. In the same spore, one capsule contained oblique filament turns to the longitudinal axis of the capsule, while the other capsule contained perpendicular turns. SEM revealed completely different shell ridge patterns than those described by light microscopy in the original description. This emphasizes the necessity of SEM in the reliable description of any myxosporean genera with external shell ornamentation like Ortholinea and Chloromyxum. The present species is considered the first (purely) freshwater Ortholineadescribed from a proper freshwater host. Three different methods of isolation and preparation of coelozoic spores for SEM were evaluated. The best combination was using a syringe filter holder with a membrane filter of 5 μm pore nucleopore filters.
Alexander Kudryavtsev, Klaus Hausmann
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 91-96
Thecamoeba aesculea n. sp. was isolated and described from the surface of the bark of Aesculus hippocastanum and from terrestrial mosses growing on it. This amoeba is superficially similar to Thecamoeba sphaeronucleolus, but comparison of the newly isolated strain with the photographs and video records of the type strain of this species reveals differences which show that the two strains do not belong to the same morphospecies. The data obtained indicate the necessity of further comparative studies on the diversity of thecamoebian ‘morphospecies’ to outline clearer borders between them.
Áron Keve Kiss, Júlia Katalin Török, Éva Ács, Keve Tihamér Kiss
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 97-110
Three new, minute testate amoeban species smaller than 15 μm, including one new genus, are described from the plankton of the River Danube (Hungary) using high resolution video micrography. Pseudodifflugia klarae nov. spec. is characterised by an oval/pyriform, rigid, slightly compressed, scarcely or densely agglutinated test with a length of 8–14 μm. Its aperture is irregular in outline and inconspicuous; the nucleus contains one nucleolus and a few bent rods in the nucleoplasm. Bereczkya nov. gen., an incertae sedis cercozoan, has a minute spherical cell enclosed in a thin, rigid, more or less agglutinated organic test that is filled entirely by the cytoplasm. Its test bears an irregular and inconspicuous aperture. A collar-like ectoplasmic rim is situated in the aperture, from which a pseudopodial stem with filopodia is erected. The nucleus is slightly irregular, without a central nucleolus, but it contains rod-shaped granules in the nucleoplasm. Bereczkya minuta nov. spec. (test length: 3.5–8 μm, the diameter of the ectoplasmic rim: 0.8–2.3 μm) has a spherical test with asymmetric swellings and depressions, agglutinated with refractile mineral and other flat or irregularly-shaped xenosomes that may sometimes be almost entirely absent. Paramphitrema muelleri nov. spec. has a tubular or lemon-like test (length: 13–17 μm), which tapers towards the rigid apertures. The test is rigid, agglutinated and ism circular in cross section. The nucleus is vesicular. Thin filopodia, as well as 1–2 thick, straight, unbranched, tubular pseudopodia are produced.
Martin Mrva
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 111-117
Lieberkuehnia wageneri Claparède et Lachmann, 1859, a poorly known freshwater foraminiferan, was re-discovered after 38 years in a moss sample from an oak-hornbeam forest in Malé Karpaty Mts. (Western Slovakia). The species was taxonomically revised, re-described using light microscopical observations, and its occurrence and ecology were reviewed. Its locomotive form is typical with membranous and flexible ovoid test having a single terminal aperture from which a broad pseudopodial network emerges on a pseudopodial peduncle. Additional data and details are described, illustrated and discussed. Lieberkuehnia wageneri is known from various freshwater, soil and marine habitats in Western and Middle Europe, suggesting a high ecological tolerance and wide distribution. It is hoped that the observations reported in this paper will aid the identification of this species based on the locomotive morphology at the light microscopical level.
Willem H. De Smet
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 119-126
A new testate amoeba Scutiglypha cabrolae sp. n. is described from a small lake located in the caldera of Licancabur volcano, central Andes, at 5916 m above sea level. Its morphology was investigated using light and scanning electron microscopy. The main characteristics of the new species are: thick-set ovate test, length/width ratio 1.4; relatively small size, mean length × width: 69 × 48 μm; 3–4 rows of apertural plates, apertural plates of first row lozenge-shaped, oral margin with median tooth and (5)–6 lateral toothlets; body-plates scutiform, broad, with weakly crenulated oral and aboral margin.
Daniel J. G. Lahr, Sônia G. B. C. Lopes
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 127-142
The taxonomic identity in microbial eukaryotes remains an impediment to discussing ecology, biogeography and phylogeny, mainly due to a lack of standards in organism descriptions and few comparative works. The lobose testate amoebae (Arcellinida) present an ideal study system, as progress is severely hindered due to taxonomic confusion. In the present survey, we have examined the morphology, biometry and ecology of 2400 individuals in the genus Arcella Ehrenberg, 1832, collected from the Tiete River in Sao Paulo, Brazil. We then contrasted these new data with 26 previously described species, varieties and forms, looking for consistencies and trying to establish distinct entities. Using a combination of morphology and multivariate statistics we were able to determine 4 distinct taxa (Arcella hemisphaerica, Arcella discoides, Arcella gibbosa and Arcella brasiliensis), each of them encompassing a number of other non-distinct nominal taxa. We describe in detail each of the 4 taxa with notes on ecology and biogeography, and list the indistinguishable names in an effort to make identification and taxonomy in the testate amoebae a more objective and precise exercise by clarifying the taxonomic identity.
Milcho Todorov
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 143-151
Shell ultra-structure and morphometrical variability of Nebela tenella were investigated using scanning electron microscopy (SEM). N. tenella was isolated from two widely separated populations, one from Switzerland and another from Canada. The shell’s structural elements were similar to those of the other nebelids, but N. tenella has a characteristic peculiarity – always present depressions on the shell surface, which makes an uneven outline of the shell. Moreover, light microscopy and SEM study showed that the collar of the N. tenella represents a turned-over continuation of the neck, which is covered by the same idiosomes as on the shell body. The biometrical analysis showed that the majority of the basic characters of N. tenella vary moderately and give continuous series of transition forms. According to the shell depth and the ratio depth/width both populations were significantly different of each other. Variation coefficients showed that the variability of the characters differs in both populations and the Swiss population is more stable than the Canadian one. All new obtained data for N. tenella raise the question whether the shell’s size, cross section and ultramorphology are reliable enough as characters for the differentiation of N. tenella and N. griseola, and whether they are two distinct species or should just be considered as ecophenotypic variation within one species?
Nicolas P. Dolapsakis, Athena Economou-Amilli
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 153-170
Genus Amphidinium Claparède et Lachmann (Gymnodiniales, Dinophyceae) sensu lato has recently undergone a reappraisal using extended microscopical methods and genetic comparisons, with the type species and morphologically similar species used for the redescription of the genus Amphidinium sensu stricto. Within the latter concept of the genus, the new species Amphidinium thermaeum is established using light and scanning electron microscopy in combination with LSU rDNA phylogeny. This species was isolated from the Thermaikos Gulf in Greece, and its description is largely based on observations of cultured material. The main diacritic features distinguishing A. thermaeum from related taxa were: shape, size and plasticity of the cell, position of distal and proximal cingulum ends, site of longitudinal flagellar insertion, sulcal course, pusule details, plastid characteristics, and mode of cell division. Genetic phylogeny applying Bayesian Inference, Maximum Likelihood, and Neighbor-Joining analyses, places A. thermaeum in an independent position within the Amphidinium sensu stricto monophyletic group, and the new species is closely related to its small and morphologically similar siblings (A. massartii, A. klebsii, A. trulla, A. gibbosum, A. carterae).
Daode Ji, Joong Ki Choi, Alan Warren, Weibo Song, Henglong Xu
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 171-183
Three marine peritrichous ciliates, Zoothamnium alrasheidi spec. nov., Z. marinum Kahl, 1933 and Z. vermicola Precht, 1935, were isolated from littoral areas near Qingdao, China. The living morphology, infraciliature and silverline system were studied in living and silver-impregnated specimens. Zoothamnium alrasheidi is distinguished from its congeners by the giant, leaf-shaped colony, the differentiation of zooids, the structure of the infundibular polykineties and in having 57–75 silverlines between the oral area and the trochal band and 24–42 between the trochal band and the scopula. Zoothamnium marinum and Z. vermicola are reported for the first time in over 70 years. Each was identified by its zooid shape and size, colony shape, the branching pattern of its stalk and its marine habitat. As a result of the present study, additional features for characterizing these species now include the structure of infundibular polykinety 3 and the number of silverlines between the aboral trochal band and (a) the scopula, and (b) the peristomial lip. Redescriptions and improved diagnoses of both species are supplied based on the Chinese populations.
Mohamad Ahmad Ali
Acta Protozoologica, Volume 48, Issue 2, 2009, pp. 185-190
Ortholinea africanus Abdel-Ghaffar et al., 2008 is re-described using light and scanning electron microscopy (SEM) to reveal the external ornamentation of the spores. Present spores matched the original description in morphology but were larger in all dimensions. They measured 9.6 ± 0.8 (8.1–10.9) μm in length, 9.5 ± 0.6 (8.8–10.9) μm in width and 8.9 ± 0.4 (8.6–9.1) μm in thickness. Polar capsules were 3.9 ± 0.3 (3.0–4.3) μm in length with polar filaments turned 4–6 turns. The pattern of polar filament coils was different in each of the polar capsules. In the same spore, one capsule contained oblique filament turns to the longitudinal axis of the capsule, while the other capsule contained perpendicular turns. SEM revealed completely different shell ridge patterns than those described by light microscopy in the original description. This emphasizes the necessity of SEM in the reliable description of any myxosporean genera with external shell ornamentation like Ortholinea and Chloromyxum. The present species is considered the first (purely) freshwater Ortholineadescribed from a proper freshwater host. Three different methods of isolation and preparation of coelozoic spores for SEM were evaluated. The best combination was using a syringe filter holder with a membrane filter of 5 μm pore nucleopore filters.
Publication date: 2009
Editor-in-Chief: Krzysztof Wiąckowski
Regina Gabilondo, Wilhelm Foissner
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 1-24
Fuscheriid haptorids are characterized by meridionally extending ciliary rows clearly separated from the dikinetidal circumoral kinety; a two- or three-rowed dorsal brush; and oral basket rods (nematodesmata) originating from both, the circumoral dikinetids and from some oralized monokinetids in the anterior portion of the ciliary rows. Using standard morphological methods, we describe four new fuscheriid taxa, each discovered in a specific biogeographic region. Fuscheriides tibetensis nov. gen., nov. spec. has rod-shaped extrusomes and two dorsal brush rows. It is a small (~ 80 × 10 μm), slender ciliate with only seven ciliary rows, and was discovered in grassland soil of southern Tibet, about 4600 m above sea-level. Aciculoplites ethiopiensis nov. gen., nov. spec. has acicular extrusomes and two dorsal brush rows. It is a middle-sized (~ 100 × 30 μm), oblong ciliate with about 22 ciliary rows, and was discovered in floodplain soil from a lake in Ethiopia. Fuscheria uluruensis nov. spec., which we discovered in mud and aeolic soil from pools on top of the Ayers Rock in the red centre of Australia, is unique in having the macronucleus split into about 12 oblong nodules. The nodules originate post-divisionally via the branching macronucleus strand, as in multinucleate spathidiids. Fuscheria nodosa salisburgensis nov. sspec., which was discovered in mud and soil of a meadow pool in Salzburg (Austria), has a long, tortuous macronucleus and about 45 ciliary rows. The resting cyst has an escape apparatus absent from the cyst of F. uluruensis, indicating that Fuscheria is non-monophyletic.
Julia Walochnik, Janez Mulec
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 25-33
This is the first report on the diversity of small free-living amoebae (FLA) in carbonate precipitating habitats in karst caves. Of 11 samples from nine different habitats in four Slovenian karst caves ten samples were positive for FLA, four strains were successfully isolated and transferred to clonal monoxenic cultures, including Acanthamoeba castellanii genotype T4, Echinamoeba silvestris, Hartmannella vermiformis, and a new vahlkampfiid amoeba Allovahlkampfia spelaea gen. nov., sp. nov. The latter was isolated from a stromatolitic stalagmite, a typical biogenic speleothem. Echinamoeba silvestris was identified from an aerophytic algal community and Acanthamoeba and Hartmannella were isolated from a cave pool with floating calcite rafts. The grazing of FLA on bacteria may help in creating conditions that enhance carbonate precipitation.
Maillo-Bellón Pedro-Andrés
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 35-39
Spore variability of Ceratomyxa appendiculata Thélohan, 1892, found in the gallbladder of black angler-fish, Lophius budegassa from NE Spain were studied by light microscopy and, for the first time, by scanning electron microscopy. More than 18,000 spores of C. appendiculata were examined, classified and quantified. Of this, 98.31% were bivalvular normal spores, the rest were abnormal spores (1.63% were trivalvular spores and 0.06% were tetravalvular spores). The monthly evolution of these spores was followed for ten months. Differences among the proportions of trivalvular spores in different months were significant. Percentage of trivalvular spores ranged from 9.90% (May) to 0.00% (December). The highest percentage of tetravalvular spores was reached in november (0.39%). Some polysporous trophozoites can produce simultaneously normal and abnormal spores.
Rolf Michel, Bärbel Hauröder, Lothar Zöller
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 41-49
Among a population of Thecamoeba quadrilineata (Thecamoebidae) isolated from moss samples some trophozoites harboured intracellular aggregates of round-oval parasites which turned out to be spores with a real nucleus. These organisms were supposed to be fungal endoparasites beginning their development within the nucleus of the host invaded by young parasitic stages after the host amoeba had engulfed free spores from the environment. The complete developmental cycle was studied by electron microscopy, showing the intranuclear growth of freshly invaded young stages into large spore forming parasites differentiating into a great number of spores – all within the border of the host’s nuclear membrane. These spores were not released into the environment until the death and decay of the host amoeba, where they could be ingested as infective stages by hitherto not infected thecamoebae. Host range studies with various free-living amoebae (FLA) showed that T. striata and T. terricola were as permissive to infection as the original host T. quadrilineata. Sappinia was only susceptible to a certain extent and therefore not considered as possible natural host. Remarkably, this observation shows that both nuclei of the bi-nucleate amoeba became simultaneously infected. The present morphological description corresponds to early observations with fungal intranuclear parasites called Nucleophaga Dangeard, 1887. However, genetic and phylogenetic studies have to corroborate the supposed fungal nature.
Adam Cieślak, Svetlana Kišidayová, Małgorzata Szumacher-Strabel
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 51-61
The effects of linoleic acid supplementation on protozoa counts, fermentation parameters and fatty-acid composition of Entodinium caudatum and Diploplastron affine were examined in in vitro cultures. Entodinium caudatum (EC) and Diploplastron affine (DA) were isolated from the rumen of sheep (Slovak Merino breed) and cultivated anaerobically in the presence of bacteria in caudatum-type medium. To test the effect of soluble linoleic acid (LA) on protozoan growth, both ciliate species were supplemented with LA (1.51 μg/L) on the day of dilution over a 30-day period. Twenty-four-hour fermentation parameters were examined on both ciliate cultures and their respective bacterial fractions. Ciliate counts of both EC and DA cultures were not significantly affected by supplemented LA. The major impact of the soluble form of LA supplement was found in the bacterial fractions of both ciliate cultures. LA supplementation had a greater effect on fermentation parameters and fatty-acid contents in the EC experimental groups than in the DA groups. Our results suggest that experimental rumen ciliates and their associated bacterial populations had different metabolic responses to the tested form and concentration of supplemented LA.
Marta Palusińska-Szysz, Anna Turska-Szewczuk, Magdalena Karaś, Ryszard Russa, Wincenty J. Drożański
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 63-72
The cellular fatty acid composition of Acanthamoeba castellanii, a unicellular bacteriovorous organism, was reinvestigated. Lipids from amoebae grown axenically in proteose peptone-yeast extract-glucose medium were extracted with chloroform–methanol and separated by silicic acid column chromatography into non-polar and polar fractions. The fatty acid composition of the lipids and the double-bond position of the unsaturated acids have been determined by capillary gas chromatography-mass spectrometry (GC-MS) of their corresponding methyl esters, 2-alkenyl-4,4-dimethyloxazoline (DMOX) derivatives and dimethyldisulfide (DMDS) adducts. Evidence is given that lipids from A. castellanii in addition to the three already identified saturated straight chain fatty acids: tetradecanoic (C14:0), hexadecanoic (C16:0), octadecanoic (C18:0), and six preponderant unsaturated fatty acids: hexadecenoic (C16:1 Δ7), octadecenoic (C18:1 Δ9), octadecadienoic (C18:2 Δ9,12), eicosadienoic (C20:2 Δ11,14), eicosatrienoic (C20:3 Δ8,11,14), and eicosatetraenoic (C20:4 Δ5,8,11,14), contain additionally four very long chain unsaturated fatty acids: octacosenoic (C28:1 Δ21), octacosadienoic (C28:2 Δ5,21), triacontadienoic (30:2 Δ21,24), and triacontatrienoic (C30:3 Δ5,21,24) previously unreported in lipids of A. castellanii. These new long chain fatty acids account for approximately 25% of total fatty acids. To our knowledge, this is the first report of very long chain polyenoic fatty acids present in lipids extracted from A. castellanii cells.
Daniel Rodrigues-Silva, Celso Vataru Nakamura, Benedito Prado Dias Filho, Tânia Ueda-Nakamura, Diógenes Aparício Garcia Cortez
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 73-81
We assessed the biological activity of a crude extract, a mixture of several fractions, and a pure compound obtained from Piper ovatum Vahl against promastigote and amastigote forms of Leishmania amazonensis. The medicinal plant P. ovatum is used popularly as an anesthetic and anti-inflammatory. This study included the extraction process and bioassay-guided fractionation by the adsorption chromatography and Sephadex LH-20 method. A progressive increase in the antileishmanial effect was observed in the course of fractionation. The 50% inhibitory concentration (IC50) for dichloromethane-ethyl acetate (1:1 v/v) fraction was 2.1 μg/ml and 24 μg/ml; mixture of piperovatine: piperlongumune (2:3) 0.9 μg/ml and 24 μg/ml; piperovatine (1) 9.5 μg/ml and 10 μg/ml; and piperlonguminine (2) 2.5 μg/ml and 9.0 μg/ml, for promastigote and amastigote forms, respectively. Cytotoxicity analysis indicated that these toxic concentrations were much higher for J774G8 macrophages and Vero cells than for the protozoans. The mixture of piperovatine: piperlongumune (2:3) showed important antiprotozoal activity against the amastigote and promastigote forms of L. amazonensis, and it produced morphological changes in promastigotes and amastigotes at 0.9 μg/ml and 24 μg/ml (50% growth inhibition concentration), respectively, including intense cytoplasmic vacuolization, mitochondrial swelling, and mitochondrial damage, as revealed by transmission electron microscopy.
Saugata Basu, Biplob Kr. Modak, Durga P. Haldar
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 83-89
Two new myxozoan species – Myxobolus analfinus sp. n. and Myxobolus debsantus sp. n. are described from Heteropneustes fossilis (Bloch) and Catla-Rohu hybrid carp [Male parent fish Catla catla (Hamilton Buchanan) × Female parent fish Labeo rohita (Hamilton- Buchanan)], respectively. Spores of Myxobolus analfinus are oval with slightly acuminate anterior end and large prominent intercapsular notch. On the other hand, in Myxobolus debsantus spores are spherical to oval with intercapsular notch and posterior sutural markings. In both the myxobolid species polar capsules are unequal. The detailed light microscopic and SEM structures and measurements of these two myxozoans are given.
Regina Gabilondo, Wilhelm Foissner
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 1-24
Fuscheriid haptorids are characterized by meridionally extending ciliary rows clearly separated from the dikinetidal circumoral kinety; a two- or three-rowed dorsal brush; and oral basket rods (nematodesmata) originating from both, the circumoral dikinetids and from some oralized monokinetids in the anterior portion of the ciliary rows. Using standard morphological methods, we describe four new fuscheriid taxa, each discovered in a specific biogeographic region. Fuscheriides tibetensis nov. gen., nov. spec. has rod-shaped extrusomes and two dorsal brush rows. It is a small (~ 80 × 10 μm), slender ciliate with only seven ciliary rows, and was discovered in grassland soil of southern Tibet, about 4600 m above sea-level. Aciculoplites ethiopiensis nov. gen., nov. spec. has acicular extrusomes and two dorsal brush rows. It is a middle-sized (~ 100 × 30 μm), oblong ciliate with about 22 ciliary rows, and was discovered in floodplain soil from a lake in Ethiopia. Fuscheria uluruensis nov. spec., which we discovered in mud and aeolic soil from pools on top of the Ayers Rock in the red centre of Australia, is unique in having the macronucleus split into about 12 oblong nodules. The nodules originate post-divisionally via the branching macronucleus strand, as in multinucleate spathidiids. Fuscheria nodosa salisburgensis nov. sspec., which was discovered in mud and soil of a meadow pool in Salzburg (Austria), has a long, tortuous macronucleus and about 45 ciliary rows. The resting cyst has an escape apparatus absent from the cyst of F. uluruensis, indicating that Fuscheria is non-monophyletic.
Julia Walochnik, Janez Mulec
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 25-33
This is the first report on the diversity of small free-living amoebae (FLA) in carbonate precipitating habitats in karst caves. Of 11 samples from nine different habitats in four Slovenian karst caves ten samples were positive for FLA, four strains were successfully isolated and transferred to clonal monoxenic cultures, including Acanthamoeba castellanii genotype T4, Echinamoeba silvestris, Hartmannella vermiformis, and a new vahlkampfiid amoeba Allovahlkampfia spelaea gen. nov., sp. nov. The latter was isolated from a stromatolitic stalagmite, a typical biogenic speleothem. Echinamoeba silvestris was identified from an aerophytic algal community and Acanthamoeba and Hartmannella were isolated from a cave pool with floating calcite rafts. The grazing of FLA on bacteria may help in creating conditions that enhance carbonate precipitation.
Maillo-Bellón Pedro-Andrés
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 35-39
Spore variability of Ceratomyxa appendiculata Thélohan, 1892, found in the gallbladder of black angler-fish, Lophius budegassa from NE Spain were studied by light microscopy and, for the first time, by scanning electron microscopy. More than 18,000 spores of C. appendiculata were examined, classified and quantified. Of this, 98.31% were bivalvular normal spores, the rest were abnormal spores (1.63% were trivalvular spores and 0.06% were tetravalvular spores). The monthly evolution of these spores was followed for ten months. Differences among the proportions of trivalvular spores in different months were significant. Percentage of trivalvular spores ranged from 9.90% (May) to 0.00% (December). The highest percentage of tetravalvular spores was reached in november (0.39%). Some polysporous trophozoites can produce simultaneously normal and abnormal spores.
Rolf Michel, Bärbel Hauröder, Lothar Zöller
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 41-49
Among a population of Thecamoeba quadrilineata (Thecamoebidae) isolated from moss samples some trophozoites harboured intracellular aggregates of round-oval parasites which turned out to be spores with a real nucleus. These organisms were supposed to be fungal endoparasites beginning their development within the nucleus of the host invaded by young parasitic stages after the host amoeba had engulfed free spores from the environment. The complete developmental cycle was studied by electron microscopy, showing the intranuclear growth of freshly invaded young stages into large spore forming parasites differentiating into a great number of spores – all within the border of the host’s nuclear membrane. These spores were not released into the environment until the death and decay of the host amoeba, where they could be ingested as infective stages by hitherto not infected thecamoebae. Host range studies with various free-living amoebae (FLA) showed that T. striata and T. terricola were as permissive to infection as the original host T. quadrilineata. Sappinia was only susceptible to a certain extent and therefore not considered as possible natural host. Remarkably, this observation shows that both nuclei of the bi-nucleate amoeba became simultaneously infected. The present morphological description corresponds to early observations with fungal intranuclear parasites called Nucleophaga Dangeard, 1887. However, genetic and phylogenetic studies have to corroborate the supposed fungal nature.
Adam Cieślak, Svetlana Kišidayová, Małgorzata Szumacher-Strabel
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 51-61
The effects of linoleic acid supplementation on protozoa counts, fermentation parameters and fatty-acid composition of Entodinium caudatum and Diploplastron affine were examined in in vitro cultures. Entodinium caudatum (EC) and Diploplastron affine (DA) were isolated from the rumen of sheep (Slovak Merino breed) and cultivated anaerobically in the presence of bacteria in caudatum-type medium. To test the effect of soluble linoleic acid (LA) on protozoan growth, both ciliate species were supplemented with LA (1.51 μg/L) on the day of dilution over a 30-day period. Twenty-four-hour fermentation parameters were examined on both ciliate cultures and their respective bacterial fractions. Ciliate counts of both EC and DA cultures were not significantly affected by supplemented LA. The major impact of the soluble form of LA supplement was found in the bacterial fractions of both ciliate cultures. LA supplementation had a greater effect on fermentation parameters and fatty-acid contents in the EC experimental groups than in the DA groups. Our results suggest that experimental rumen ciliates and their associated bacterial populations had different metabolic responses to the tested form and concentration of supplemented LA.
Marta Palusińska-Szysz, Anna Turska-Szewczuk, Magdalena Karaś, Ryszard Russa, Wincenty J. Drożański
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 63-72
The cellular fatty acid composition of Acanthamoeba castellanii, a unicellular bacteriovorous organism, was reinvestigated. Lipids from amoebae grown axenically in proteose peptone-yeast extract-glucose medium were extracted with chloroform–methanol and separated by silicic acid column chromatography into non-polar and polar fractions. The fatty acid composition of the lipids and the double-bond position of the unsaturated acids have been determined by capillary gas chromatography-mass spectrometry (GC-MS) of their corresponding methyl esters, 2-alkenyl-4,4-dimethyloxazoline (DMOX) derivatives and dimethyldisulfide (DMDS) adducts. Evidence is given that lipids from A. castellanii in addition to the three already identified saturated straight chain fatty acids: tetradecanoic (C14:0), hexadecanoic (C16:0), octadecanoic (C18:0), and six preponderant unsaturated fatty acids: hexadecenoic (C16:1 Δ7), octadecenoic (C18:1 Δ9), octadecadienoic (C18:2 Δ9,12), eicosadienoic (C20:2 Δ11,14), eicosatrienoic (C20:3 Δ8,11,14), and eicosatetraenoic (C20:4 Δ5,8,11,14), contain additionally four very long chain unsaturated fatty acids: octacosenoic (C28:1 Δ21), octacosadienoic (C28:2 Δ5,21), triacontadienoic (30:2 Δ21,24), and triacontatrienoic (C30:3 Δ5,21,24) previously unreported in lipids of A. castellanii. These new long chain fatty acids account for approximately 25% of total fatty acids. To our knowledge, this is the first report of very long chain polyenoic fatty acids present in lipids extracted from A. castellanii cells.
Daniel Rodrigues-Silva, Celso Vataru Nakamura, Benedito Prado Dias Filho, Tânia Ueda-Nakamura, Diógenes Aparício Garcia Cortez
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 73-81
We assessed the biological activity of a crude extract, a mixture of several fractions, and a pure compound obtained from Piper ovatum Vahl against promastigote and amastigote forms of Leishmania amazonensis. The medicinal plant P. ovatum is used popularly as an anesthetic and anti-inflammatory. This study included the extraction process and bioassay-guided fractionation by the adsorption chromatography and Sephadex LH-20 method. A progressive increase in the antileishmanial effect was observed in the course of fractionation. The 50% inhibitory concentration (IC50) for dichloromethane-ethyl acetate (1:1 v/v) fraction was 2.1 μg/ml and 24 μg/ml; mixture of piperovatine: piperlongumune (2:3) 0.9 μg/ml and 24 μg/ml; piperovatine (1) 9.5 μg/ml and 10 μg/ml; and piperlonguminine (2) 2.5 μg/ml and 9.0 μg/ml, for promastigote and amastigote forms, respectively. Cytotoxicity analysis indicated that these toxic concentrations were much higher for J774G8 macrophages and Vero cells than for the protozoans. The mixture of piperovatine: piperlongumune (2:3) showed important antiprotozoal activity against the amastigote and promastigote forms of L. amazonensis, and it produced morphological changes in promastigotes and amastigotes at 0.9 μg/ml and 24 μg/ml (50% growth inhibition concentration), respectively, including intense cytoplasmic vacuolization, mitochondrial swelling, and mitochondrial damage, as revealed by transmission electron microscopy.
Saugata Basu, Biplob Kr. Modak, Durga P. Haldar
Acta Protozoologica, Volume 48, Issue 1, 2009, pp. 83-89
Two new myxozoan species – Myxobolus analfinus sp. n. and Myxobolus debsantus sp. n. are described from Heteropneustes fossilis (Bloch) and Catla-Rohu hybrid carp [Male parent fish Catla catla (Hamilton Buchanan) × Female parent fish Labeo rohita (Hamilton- Buchanan)], respectively. Spores of Myxobolus analfinus are oval with slightly acuminate anterior end and large prominent intercapsular notch. On the other hand, in Myxobolus debsantus spores are spherical to oval with intercapsular notch and posterior sutural markings. In both the myxobolid species polar capsules are unequal. The detailed light microscopic and SEM structures and measurements of these two myxozoans are given.
2023
1.5
2023
0.17
2023
0.592
2023
39
2023
0.807
2023
2.0
