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In recent years, Tetrahymena species have been used as model organisms for research in a wide range of fields, highlighting the need for a fuller understanding of the taxonomy of this group. It is in this context that this paper uses living observation and silver staining methods to investigate the morphology and infraciliature of one Tetrahymena species, T. setosa (Schewiakoff 1892 Verh. Naturh. Med. Ver. Heidelb., 4:544) McCoy (1975) Acta Protozool., 14:253; the senior subjective synonym of T. setifera Holz and Corliss (1956) J. Protozool., 3:112; isolated from a freshwater pond in Harbin, north‐eastern China. This organism can be distinguished from other described Tetrahymena species mainly by its single caudal cilium, which is about twice the length of the somatic ciliature. While the Harbin isolate appears similar to the population described by Holz and Corliss (1956) J. Protozool., 3:112, an improved diagnosis for T. setosa is given based on the previous descriptions and the Harbin population. In summary, this species can be recognized mainly by the combination of the following characters: body in vivo approximately 40 μm × 25 μm, 21–26 somatic kineties, one to four contractile vacuole pores associated with meridians 6–11 and a single caudal cilium. The small subunit ribosomal (SSU) rRNA gene and the cox1 gene sequences of Harbin population are also characterized in order to corroborate that the isolated species branches in phylogenetic trees as a T. setosa species. The phylogenetic analysis also indicated that sequences of populations of Tetrahymena species should be published with detailed morphological identifications. [ABSTRACT FROM AUTHOR]

ABSTRACT Acanthamoeba genus is divided into 20 genotypes (T1-T20) on the basis of the gene encoding 18S rRNA sequence. Using of at least 2 kbp gene fragments is strongly recommended to identify new genotypes and 5% difference is commonly used as a criterion of new genotypes, however, this value is questionable. In this paper, Polish Acanthamoeba strains described earlier on the basis of ~850 bp Ami fragment of 18S rRNA gene as T4, T11 and a new T16 genotype, have been analyzed using near-complete sequence of the gene. This analysis was needed because the Ami fragment does not reveal full variability within 18S rRNA gene. Phylogenetic analysis based on Ami fragment is biased by artifacts in the construction of the tree, so the fragment should not be used for identification of new putative Acanthamoeba genotypes. The analysis confirmed that the Polish sequences represent T4 and T11 genotypes and that the strains described earlier as T16 genotype are in fact a new subgroup of the T20 genotype and that this genotype should be divided into two subgroups: T20a (two strains described by [ J. Eukaryot. Microbiol. 62 (2015) 69]) and T20b (11 Polish strains described in this study). The T20b subgroup was isolated from both clinical samples and water bodies used by people as bathing places and there is a risk of infection for humans during contact with water. [ABSTRACT FROM AUTHOR]

Presents the abstracts of papers presented in the annual meetings of associations of protozoologists in 2004.

Many heterotrophic microbial eukaryotes are size‐selective feeders. Some microorganisms increase their size by forming multicellular colonies. We used choanoflagellates, Salpingoeca helianthica, which can be unicellular or form multicellular colonies, to study the effects of multicellularity on vulnerability to predation by the raptorial protozoan predator, Amoeba proteus, which captures prey with pseudopodia. Videomicrography used to measure the behavior of interacting S. helianthica and A. proteus revealed that large choanoflagellate colonies were more susceptible to capture than were small colonies or single cells. Swimming colonies produced larger flow fields than did swimming unicellular choanoflagellates, and the distance of S. helianthica from A. proteus when pseudopod formation started was greater for colonies than for single cells. Prey size did not affect the number of pseudopodia formed and the time between their formation, pulsatile kinematics and speed of extension by pseudopodia, or percent of prey lost by the predator. S. helianthica did not change swimming speed or execute escape maneuvers in response to being pursued by pseudopodia, so size‐selective feeding by A. proteus was due to predator behavior rather than prey escape. Our results do not support the theory that the selective advantage of becoming multicellular by choanoflagellate‐like ancestors of animals was reduced susceptibility to protozoan predation. [ABSTRACT FROM AUTHOR]

Presents several abstracts of papers submitted at the Czech Section Society of Protozoologists 33rd Annual Meeting. "The Development of a Precious Strain of Eimeria Necatrix," by M. Hortvíková; "Distribution of Ciliates of Different Feeding Specializations in the Water Bodies of Different Trophy," by M. Macek, K. Simek and A. L. Vasquez; "Methods of Analysis and 3D Imaging of Protozoan Cytoloskeletal Structures Obtained by Confocal Microscopy," by J. Novy, J. Tomas and R. Janisch; "Selection and Characterization of a Precious Line of Rabbit Coccidium Eimeria Flavescen," by M. Pakandl, F. Cerník and Z. Houdek.

Presents an overview on the taxonomy and phylogeny of protists. Kinds of biotic interactions; Role of protists in support of all life on the planet Earth; Influence of protists in restricting bacterial and fungal growth in such habitats; Role of anoxic protists in altering Earth's environment chemically.

Highlights the important trends in the field of protistology. Controversy over the origin of the eukaryotic cells; Emergence of complete genome sequencing in the field of parasitology; Role of protists in global carbon and sulfur cycles.

Shows the gene organization of the entire robosomal RNA gene of Nosema spodopterae. Demonstration that the gene organization follows a significant pattern similar to the Nosema type species; Comparison with the known corresponding sequences and structures of closely related microsporidia; Suggestion that the Nosema genus may be heterogeneous.

The morphology of two oligotrich ciliates, Pelagostrombidium fallax (Zacharias, 1895) Krainer, 1991 and Limnostrombidium viride (Stein, 1867) Krainer, 1995, collected from a freshwater pond in northern China, was studied based on live observation and protargol staining. Currently, undescribed features in the girdle kinety in P. fallax are (a) sparsely spaced single argyrophilic basal bodies in the shoulder region and (b) a U‐shape formed below the buccal peristome. An improved diagnosis for P. fallax is supplied, based on previous and present morphological descriptions. In addition, certain ontogenetic stages of P. fallax are reported for the first time. During division, two new embryonic bodies are successively generated de novo, the first one goes to the proter, the second one to the opisthe; the new canal derives from the old canal. The morphology of L. viride is redescribed in detail; the Chinese population is highly consistent with populations in Europe. The SSU rRNA gene of P. fallax was sequenced for the first time. Phylogenetic analyses, based on SSU rRNA gene sequence data, reveal that P. fallax and L. viride cluster with Strombidium species while the result of an AU test did not reject the possibility of monophyly of the family Pelagostrombidiidae. [ABSTRACT FROM AUTHOR]

This revision of the classification of eukaryotes follows that of Adl et al., 2012 [J. Euk. Microbiol. 59(5)] and retains an emphasis on protists. Changes since have improved the resolution of many nodes in phylogenetic analyses. For some clades even families are being clearly resolved. As we had predicted, environmental sampling in the intervening years has massively increased the genetic information at hand. Consequently, we have discovered novel clades, exciting new genera and uncovered a massive species level diversity beyond the morphological species descriptions. Several clades known from environmental samples only have now found their home. Sampling soils, deeper marine waters and the deep sea will continue to fill us with surprises. The main changes in this revision are the confirmation that eukaryotes form at least two domains, the loss of monophyly in the Excavata, robust support for the Haptista and Cryptista. We provide suggested primer sets for DNA sequences from environmental samples that are effective for each clade. We have provided a guide to trophic functional guilds in an appendix, to facilitate the interpretation of environmental samples, and a standardized taxonomic guide for East Asian users. [ABSTRACT FROM AUTHOR]

Abstract: Three new cyrtophorian ciliates isolated from coastal areas of China were described based on morphological and genetic data. The Chlamydodon mnemosyne‐like species Chlamydodon similis sp. n. differs from its congeners mainly by its number of somatic kineties. Chlamydodon oligochaetus sp. n. is distinguished from its congeners mainly by having fewer somatic kineties, and/or an elongated body shape. Chlamydodon crassidens sp. n. is characterized mainly by an inverted triangular body shape, a posteriorly interrupted cross‐striated band (5–6 μm wide), and a large cytostome. Moreover, we provided small‐subunit (SSU) rDNA sequences of C. similis sp. n. and C. oligochaetus sp. n. Maximum likelihood (ML) and Bayesian inference (BI) consistently placed C. similis sp. n. as a sister to C. paramnemosyne, but showed different branching position of C. oligochaetus sp. n., which may be due to a low taxon sampling in the Chlamydodontidae and/or an insufficient resolution of the marker gene at species level. [ABSTRACT FROM AUTHOR]

Two new and one problematic species of pleurostomatids, Amphileptus dragescoi sp. n., A. wilberti sp. n., and A. marinus from coastal areas of the South China Sea, are described based on observations of live and protargol-impregnated specimens. Amphileptus dragescoi is different from its congeners by the presence of an apical group of extrusomes and the possession of 12-15 right and five left somatic kineties, two macronuclear nodules, and a single terminally positioned contractile vacuole. Amphileptus wilberti is diagnosed by oval or pyriform body, 15-19 right and seven or eight left somatic kineties, extrusomes arranged only in anterior portion of oral slit, usually three ventrally located contractile vacuoles, and two macronuclear nodules. Amphileptus marinus (Kahl, 1931) Song et al., 2004 is redescribed and its diagnosis is improved. One isolate which was misidentified as A. marinus by Song et al. (2004) is believed to represent an unknown form, named here as Amphileptus songi sp. n. Phylogenetic analyses of the SSU r DNA sequences indicate that the genus Amphileptus is paraphyletic, but its monophyly is not rejected by statistical tree topology tests. [ABSTRACT FROM AUTHOR]

Since the introduction of the microbial loop concept, awareness of the role played by protozooplankton in marine food webs has grown. By consuming bacteria, and then being consumed by metazooplankton, protozoa form a trophic link that channels dissolved organic material into the “classic” marine food chain. Beyond enhancing energy transfer to higher trophic levels, protozoa play a key role in improving the food quality of metazooplankton. Here, we consider a third role played by protozoa, but one that has received comparatively little attention: that as prey items for ichthyoplankton. For >100 years it has been known that fish larvae consume protozoa. Despite this, fisheries scientists and biological oceanographers still largely ignore protozoa when assessing the foodweb dynamics that regulate the growth and survival of larval fish. We review evidence supporting the importance of the protozooplankton–ichthyoplankton link, including examples from the amateur aquarium trade, the commercial aquaculture industry, and contemporary studies of larval fish. We then consider why this potentially important link continues to receive very little attention. We conclude by offering suggestions for quantifying the importance of the protozooplankton–ichthyoplankton trophic link, using both existing methods and new technologies. [ABSTRACT FROM AUTHOR]

Ancyromonas was first described in 1882 by Saville Kent, with the modern concept of the genus dating from 1979 with the work of Hänel. Since then, organisms assigned to Ancyromonas have been found to be common in diverse ecosystems, and the group's isolated phylogenetic placement renders it of considerable evolutionary interest. However, in 2008 Cavalier-Smith et al. concluded that all modern accounts of Ancyromonas were of a different organism from that described by Saville Kent, and erected the new genus Planomonas to encompass modern observations of Ancyromonas, and several new species. We critique the rationale for creating this new genus, reexamining the original sources and making additional observations using light and electron microscopy. We find that almost all the differences between the genera are mistaken or insubstantial. In particular, (1) Cavalier-Smith et al. characterized Ancyromonas sensu Saville Kent as anchoring and Planomonas as gliding, while we find that each type of organism actually does both, and (2) it was claimed that Planomonas is flattened while Ancyromonas sensu Saville Kent is not, but this argument is inconsistent. We treat Planomonas as a junior synonym of Ancyromonas, and Planomonas mylnikovi as a junior synonym of Ancyromonas sigmoides. We transfer Planomonas cephalopora, Planomonas micra, Planomonas howeae and Planomonas limna to Ancyromonas. The genus Ancyromonas therefore includes: A. sigmoides, Ancyromonas cephalopora n. comb., Ancyromonas melba, Ancyromonas sinistra, Ancyromonas micra n. comb., Ancyromonas howeae n. comb., and Ancyromonas limna n. comb. [ABSTRACT FROM AUTHOR]

Troglocorys cava n. g., n. sp. is described from the feces of wild eastern chimpanzee, Pan troglodytes schweinfurthii, in Uganda. This new species has a spherical body with a frontal lobe, a long vestibulum, a cytoproct located at the posterior dorsal side of the body, an ovoid macronucleus, a contractile vacuole near the cytoproct, and a large concavity on the left surface of the body. Buccal ciliature is non-retractable and consists of three ciliary zones: an adoral zone surrounding the vestibular opening, a dorso-adoral zone extending transversely at the basis of the frontal lobe, and a vestibular zone longitudinally extending in a gently spiral curve to line the surface of the vestibulum. Two non-retractable somatic ciliary zones comprise arches over the body surface: a short dorsal ciliary arch extending transversely at the basis of the frontal lobe and a wide C-shaped left ciliary arch in the left concavity. Because of the presence of three ciliary zones in the non-retractable buccal ciliature, the present genus might be a member of the family Blepharocorythidae, but the large left concavity and the C-shaped left ciliary arch are unique, such structures have never been described from other blepharocorythids. [ABSTRACT FROM AUTHOR]

The morphology, infraciliature, and silverline system of a new marine scuticociliate, Wilbertia typica n. g., n. sp., collected from coastal waters off northern China, were investigated. The new genus Wilbertia is characterized as follows: sculptured and dorso-ventrally flattened body; dominant buccal field that is almost completely surrounded by the paroral membrane; three apically positioned long membranelles, arranged in parallel; membranelle (M)1 and M2 prominent, M3 small; reticulate silverline system. The type species W. typica n. sp. is defined by having a conspicuous anterior beak-like protrusion; five to eight caudal cilia; M1 four-rowed, M2 two-rowed; M3, single-rowed, bipartite; 15 or 16 somatic kineties; contractile vacuole positioned just posterior to the buccal field; globular macronucleus. The small subunit ribosomal DNA sequence of W. typica is 98.5% similar to the similar morphotype, Eurystomatella sinica. Phylogenetic analyses indicate that Wilbertia groups with Eurystomatella sinica forming a branch that diverges at a deep level from all other pleuronematid scuticociliates. The molecular and morphological data indicate that Wilbertia should be placed within the family Eurystomatidae, which is closely related to the well-known Cyclidiidae. [ABSTRACT FROM AUTHOR]

The trophozoites of two novel archigregarines, Selenidium pisinnus n. sp. and Filipodium phascolosomae n. sp., were described from the sipunculid Phascolosoma agassizii. The trophozoites of S. pisinnus n. sp. were relatively small (64–100 μm long and 9–25 μm wide), had rounded ends, and had about 21 epicytic folds per side. The trophozoites of F. phascolosomae n. sp. were highly irregular in shape and possessed hair-like surface projections. The trophozoites of this species were 85–142 μm long and 40–72 μm wide and possessed a distinct longitudinal ridge that extended from the mucron to the posterior end of the cell. In addition to the small subunit (SSU) rDNA sequences of these two species, we also characterized the surface morphology and SSU rDNA sequence of Selenidium orientale, isolated from the sipunculid Themiste pyroides. Molecular phylogenetic analyses demonstrated that S. pisinnus n. sp. and S. orientale formed a strongly supported clade within other Selenidium and archigregarine-like environmental sequences. Filipodium phascolosomae n. sp. formed the nearest sister lineage to the dynamic, tape-like gregarine Selenidium vivax. Overall, these data enabled us to reassess the molecular systematics of archigregarines within sipunculid hosts and make the following revisions: (1) Filipodium was transferred from the Lecudinidae (eugregarines) to the Selenidiidae (archigregarines), and (2) Platyproteum n. g. was established for Platyproteum vivax n. comb. (ex. S. vivax) in order to account for the highly divergent morphological features and better resolved phylogenetic position of this lineage. [ABSTRACT FROM AUTHOR]

The morphology and genetic characterisation of a new species of piroplasm identified in the blood of the Gilbert's potoroo ( Potorous gilbertii) from the Two Peoples Bay Nature Reserve near Albany, Western Australia, is described from blood and tissue samples from 16 Gilbert's potoroos. Microscopy of blood showed these parasites are highly pleomorphic with a mean length of 1.8 μm and mean width of 0.85 μm. Phylogenetic analysis of 18S rRNA sequence data identified the piroplasm as a new species of Theileria that is closely related to other Australian marsupial piroplasm species. Based on biological and molecular data, it is proposed that the parasite from Gilbert's potoroo be given the name Theileria gilberti n. sp. [ABSTRACT FROM AUTHOR]

The planktonic ciliate Balanion masanensis n. sp. is described from living cells, from cells prepared by quantitative protargol staining (QPS), scanning electron microscopy (SEM), and transmitted electron microscopy (TEM) preparations, and the sequence of its nuclear small subunit rDNA (SSU rDNA) is reported. This species is almost ovoid with a flattened anterior oral region when the cells are alive and stained. The flattened anterior region of a living cell often forms a dome with the perimeter receded in a groove, and this region is easily inflated or depressed. In SEM photos, a brosse of six to nine monokinetids (or possibly three to five dikinetids) was observed inside the circumoral dikinetids. In TEM photos, circumoral microtubular ribbons were observed below the oral cilia, which along with the oral flaps were 8–16 μm in length. The cytostome is a slight funnel-like central depression on the flattened anterior end. The morphological characteristics of this ciliate are identical to those of the genus Balanion (Order Prorodontida). The ranges (and mean±standard deviation) of cell length, cell width, and oral diameter of living cells (n=23–26) were 27–43 μm (35.2±4.6), 25–32 μm (28.6±2.3), and 25–30 μm (27.6±1.3), respectively, while those of the QPS-stained specimens (n=70) were 23–37 μm (30.6±3.5), 26–35 μm (30.7±2.2), and 26–33 μm (29.5±1.5), respectively. Forty-six to 55 somatic kineties (SKs) were equally spaced around the cell body and extended from the oral to near the posterior regions with 24–50 monokinetids per kinety. Each kinetid bore a cilium 2.8–7.2 μm long. A caudal cilium (ca 14 μm long) arose on the posterior end. The single ellipsoid macronucleus is 6.8–13.4 × 6.8–10.5 μm, accompanied by a single micronucleus (2.0–2.8 × 1.5–2.5 μm) visible only in QPS specimens. Because, the cell size, the number of SKs, and the number of kinetosomes per SK of this ciliate were much greater than those of Balanion comatum and Balanion planctonicum, the only two Balanion species so far reported, we have established B. masanensis n. sp. When properly aligned, the sequence of the SSU rDNA of B. masanensis n. sp. (GenBank Accession No. AM412525) was approximately 9% different from that of Coleps hirtus (Colepidae, Prorodontida) and 12% different from that of Prorodon teres (Prorodontidae, Prorodontida). [ABSTRACT FROM AUTHOR]

Examination of mucus discharged from the blowhole of Atlantic bottlenose dolphin ( Tursiops truncatus) at Marine Life Oceanarium, Gulfport, Mississippi, and false killer whale ( Pseudorca crassidens) and Atlantic bottlenose dolphin at SeaWorld Orlando, Orlando, Florida, using live observations and protargol impregnation revealed mixed infections of Kyaroikeus cetarius and two new species. Planilamina n. gen. is characterized by a C-shaped argentophilic band located along the laterally flattened margin of cell and extending from the cell apex to subposterior cone-shaped podite; a deep oral cavity containing one short preoral kinety, two circumoral kineties, seven to 13 infundibular kineties, and a cytostome; a broadly funnel-shaped cytopharynx reinforced by argentophilic fibers but without nematodesmata; closely packed postoral kinetofragments set in a pocket located anterior left of the podite; and somatic kineties as a right field closely situated at the right surface and a left field bordering the anterior left margin of the oral cavity. The type species for the genus, Planilamina ovata n. sp., is distinguished from its sister species Planilamina magna n. sp. by the following characteristics: body size (28–65 × 20–43 μm vs. 57–90 × 40–63 μm), number of right field kineties (38–55 vs. 79–99), and position of the anterior end of the leftmost kinety in the right somatic field (anterior one-third vs. mid-body). The morphogenesis of Planilamina ovata is similar to that of K. cetarius. The diagnosis of Kyaroikeidae is emended to accommodate the new genus. [ABSTRACT FROM AUTHOR]

The morphology and infraciliature of a new ciliate, Tunicothrix rostrata n. g., n. sp., isolated from the Yellow Sea, are investigated using live observation and protargol impregnation. Tunicothrix rostrata measures about 160 × 40 μm in vivo, and has a frontal beak-like protrusion, a conspicuous cortical alveolar layer, two right marginal rows, and usually three distinct midventral pairs. The discovery of T. rostrata enables us to reconsider the classification of Erniella wilberti, a curious ciliate with obscure midventral pairs. Both species are highly similar in overall appearance and nuclear and ciliary pattern. Thus, they are united in a new genus of the family Urostylidae, Tunicothrix, and E. wilberti is transferred to Tunicothrix: Tunicothrix wilberti Lin and Song, 2004 n. comb. By contrast, Erniella filiformis, type species of Erniella, has several ventral rows and does not belong to the urostylids. Tunicothrix rostrata is easily distinguished from T. wilberti by its beak-like anterior protrusion and by the distinctly elongated right marginal row 2, which curves anteriorly on the dorsal side of the cells. Tunicothrix is closely related to Parabirojimia, differing by the invariably two (vs. five–eight) right marginal rows and the conspicuous (vs. ordinary) alveolar layer, a unique feature in urostylid ciliates. [ABSTRACT FROM AUTHOR]

A differentiation, based on morphological characters, between Stylonychia mytilus and Stylonychia lemnae is very difficult, especially for non-specialists. These two sibling species were considered as one species, S. mytilus, until detailed cytological and genetic studies could show the existence of two genetically isolated varieties. Further morphological and biochemical analyses verified the separation and finally in 1983 a new species S. lemnae was described. The examination of several isoenzymes revealed unambiguous differences in the banding pattern of isocitrate dehydrogenase (IDH) between these two species. Therefore, the IDH gene of 30 isolates of S. lemnae and S. mytilus coming from various regions all over the world were amplified and sequenced. The sequence analyses revealed intraspecific as well as interspecific substitutions, which were used for the development of species-specific PCR primers for both species. Application of these species-specific primer pairs now allows a very easy and clear identification of both sibling species. [ABSTRACT FROM AUTHOR]

Two marine peritrich ciliates, Vorticella fusca Precht (1935) and Vorticella parapulchella n. sp. were discovered in the littoral zone of Qingdao, northern China. Their morphology, infraciliature, and silverline system were described using live observation and silver impregnation. The poorly known species V. fusca is redescribed, adding information about the oral infraciliature and pellicular morphology. Vorticella parapulchella n. sp. is superficially similar to Vorticella pulchella Sommer (1951) but is distinguished from it by being markedly smaller and having much more widely spaced pellicular ridges. The infundibular infraciliature of V. parapulchella is extremely unusual in having infundibular polykinety 3 reduced to two rows, one of which has almost disappeared. [ABSTRACT FROM AUTHOR]

A new heterotrophic flagellate ( Andalucia godoyi n. gen. n. sp.) is described from soil. Earlier preliminary 18S rRNA analyses had indicated a relationship with the phylogenetically difficult-to-place jakobid Jakoba incarcerata. Andalucia godoyi is a small (3–5 μm) biflagellated cell with a ventral feeding groove. It has tubular mitochondrial cristae. There are two major microtubular roots (R1, R2) and a singlet root associated with basal body 1 (posterior). The microtubular root R1 is associated with non-microtubular fibres “I,”“B,” and “A,” and divides in two parts, while R2 is associated with a “C” fibre. These structures support the anterior portion of the groove. Several features of A. godoyi are characteristic of jakobids: (i) there is a single dorsal vane on flagellum 2; (ii) the C fibre has the jakobid multilaminate substructure; (iii) the dorsal fan of microtubules originates in very close association with basal body 2; and (iv) there is no “R4” microtubular root associated with basal body 2. Morphological analyses incorporating the A. godoyi data strongly support the monophyly of all jakobids. Our 18S rRNA phylogenies place A. godoyi and J. incarcerata as a strong clade, which falls separately from other jakobids. Statistical tests do not reject jakobid monophyly, but a specific relationship between Jakoba libera and J. incarcerata and/or A. godoyi is rejected. Therefore, we have established a new genus Andalucia n. gen. with the type species Andalucia godoyi n. sp., and transfer Jakoba incarcerata to Andalucia as Andalucia incarcerata n. comb. [ABSTRACT FROM AUTHOR]

The planktonic ciliate Parastrombidinopsis shimi n. gen., n. sp. is described from both living cells and quantitative protargol-stained (QPS) preparations and the sequence of the small subunit rDNA (SSU rDNA) is reported. This species is almost oval when the cells are alive; when stained, it is cylindrical for the upper two-fifths, half-bowl shaped for the middle two-fifths, and narrow rodshaped for the lower one-fifth. The ranges (and mean±standard deviation, n=20) of cell length, cell width, and oral diameter of living cells were 112–221 μm (168±39), 88–176 μm (121±30), and 53–110 μm (80±14), respectively, while those of the QPS-stained specimens (n=54) were 88–225 μm (162±29), 55–163 μm (102±19), and 53–98 μm (69±9), respectively. Thirty-six to 48 external oral polykinetids had cilia 25–40 μm long. However, unlike Strombidinopsis species sensu stricto, P. shimi has an external oral polykinetid zone that is an open circle. This species has two shorter polykinetids associated with the end of the oral polykinetid zone, deep in the oral cavity. Like Strombidinopsis species in the subclass Choreotrichia, 36–50 somatic kineties were equally spaced around the cell body and extended from the oral to the posterior regions with 68–105 dikinetids per kinety. Both kinetosomes of each kinetid bore cilia 3–10 μm long. Parastrombidinopsis shimi had 2 (1–4) ovoid macronuclei of 20–82 × 15–32 μm. When properly aligned, the sequence of the SSU rDNA of P. shimi (GenBank Accession No. AJ786648) was approximately 5% different from that of Strobilidium caudatum and 6% different from that of two Strombidinopsis species. Based both on morphology and gene sequence divergence, we establish this is as a new species in a new genus belonging to the family Strombidinopsidae. [ABSTRACT FROM AUTHOR]

This revision of the classification of unicellular eukaryotes updates that of Levine et al. (1980) for the protozoa and expands it to include other protists. Whereas the previous revision was primarily to incorporate the results of ultrastructural studies, this revision incorporates results from both ultrastructural research since 1980 and molecular phylogenetic studies. We propose a scheme that is based on nameless ranked systematics. The vocabulary of the taxonomy is updated, particularly to clarify the naming of groups that have been repositioned. We recognize six clusters of eukaryotes that may represent the basic groupings similar to traditional “kingdoms.” The multicellular lineages emerged from within monophyletic protist lineages: animals and fungi from Opisthokonta, plants from Archaeplastida, and brown algae from Stramenopiles. [ABSTRACT FROM AUTHOR]

Focuses on dinoflagellate Stoeckeria algicida from the Coastal Waters off Southern Korea. Morphology and small subunit ribosomal DNA gene sequence; Remarks on culturing behavior; Morphological characteristics.

Studies Holosticha hamulata and Holosticha heterofoissneri, two urostylid ciliates from intertidal sediments of the Yellow Sea. Morphometric data; Occurrence and ecology; Comparison between populations of Holostica heterofoissneri; Location of the contractile vacuole as a taxonomic feature.

Reports on an ultrastructural analysis of the relict mitochondrion of Cryptosporidium parvum sporozoites that includes electron tomographic reconstruction. Presence of either a single, highly-folded inner membrane or multiple internal subcompartments; Lack of tubular "crista junctions" in the infoldings of the inner membrane; Suggestion that the retention of a relict mitochondrion is a strategy for compartmentalizing away from the cytosol toxic ferrous iron and sulfide.

Describes the ultrastructure of a new microsporidian species Microgemma vivaresi causing liver cell xenoma formation in sea scorpions, Taurulus bubalis. Stages of merogony, sporogony and sporogenesis mixed in the central cytoplasm of developing xenomas; All stages with unpaired nuclei; Broadly ovoid spores; Polaroplast with up to 40 membranes arranged in pairs.

Reports on a study of encystations and excystation of Acanthamoeba castellani using transmission electron microscopy. Differentiation process induced in asynchronous cultures grown axenically; Observation of cytoplasmic vesicles containing a dense fibrous material very similar in appearance to the cyst wall, in trophozoites induced to encyst; Presence of small structures very similar to electron-dense granules in mature cysts induced to excystation.

Describes the new pleurostomatid genus Apoamphileptus. Pattern of infraciliature and other morphological features; Presence of both the postoral and the right suture in the specie; Comparison of the new species with related taxa.

Describes the isolation and characterization of two additional Paramecium mutants that fail to excise an internal eliminated sequences (IES) due to a single base change. Differentiation of a new somatic macronuclear genome in ciliated protozoa; Analysis of many IES; Functional importance of nucleotides within the consensus sequence in Paramecium.

Discusses the infection of mouse dermal fibroblasts by the monoxenous trypanosomatid protozoa Crithidia (C.) deanei and Herpetomonas (H.) roitman. Use of light and electron microscopy; Evidence of phagocytosis of trypanosomatids and survival in vertebrate cells; Role of C. deanei and H. roitmani.

Studies Nematopsis gigas n. sp. from researchers from Oporto, Portugal. Discovery of a new species of Nematopsis; Affinity on the Brazilian Nerita ascencionis; Description of the new species from the mantle tissues of the seawater gastropod.

Studies actins from five ciliate species by researchers from Japan. Significance of the circular DNA of actins cloned, sequenced and characterized by the researchers; Diversity of the actin genes obtained; Role of molecular interactions on the acceleration of the evolutionary rate of ciliate actins.

Reports on a study conducted by researchers in Italy, which represents the first extended report on a species of the ciliate genus Peritromus. Determination of the small subunit rDNA gene sequence of the ciliates; Description of the different stages of contraction of Peritromus kahli.

Presents a decadal review of the contents of "The Journal of Protozoology/Journal of Eukaryotic Microbiology from Volume 1 to Volume 50. Highlights of the continued and broad relevance of protozoa and protists to biology; Demonstration of the increasing importance of molecular approaches to the ecological study of the protists; Discussion of several advances in the field of protistology.