Coccolithophorid 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.

This 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.

Two 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.

The 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.

Using 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.

Occurrence 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.

A 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.

18S 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.