Anatoly Bobrov
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.
Anatoly Bobrov
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.
Anatoly Bobrov
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 211-219
https://doi.org/10.4467/16890027AP.16.020.6007Anatoly Bobrov
Acta Protozoologica, Volume 55, Issue 4, 2016, pp. 197-209
https://doi.org/10.4467/16890027AP.16.019.6006Anatoly Bobrov
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.
Anatoly Bobrov
Acta Protozoologica, Volume 56, Issue 3, 2017, pp. 211-216
https://doi.org/10.4467/16890027AP.17.018.7499Anatoly Bobrov
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.
Anatoly Bobrov
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