Showing papers in "Acta Protozoologica in 2010"

Morphology and Ecology in Tintinnid Ciliates of the Marine Plankton: Correlates of Lorica Dimensions

Abstract: Summary. 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.

Morphological and Molecular Characterization of Some Peritrichs (Ciliophora: Peritrichida) from Tank Bromeliads, Including Two New Genera: Orborhabdostyla and Vorticellides

Abstract: Using standard methods, we studied the morphology and 18S rDNA sequence of some peritrich ciliates from tank bromeliads of Costa Rica, Jamaica, and Ecuador. The new genus Orborhabdostyla differs from Rhabdostyla by the discoidal macronucleus. Two species from the literature and a new species from Ecuadoran tank bromeliads are combined with the new genus: O. previpes (Claparede and Lachmann, 1857) nov. comb., O. kahli (Nenninger, 1948) nov. comb., and O. bromelicola nov. spec. Orborhabdostyla bromelicola is a slender species with stalk-like narrowed posterior half and operculariid/epistylidid oral apparatus. An epistylidid relationship is also suggested by the gene sequence. Vorticella gracilis, described by Dujardin (1841) from French freshwater, belongs to the V. convallaria complex but differs by the yellowish colour and the number of silverlines. The classification as a distinct species is supported by the 18S rDNA, which differs nearly 10% from that of V. convallaria s. str. Based on the new data, especially the very stable yellowish colour, we neotypify V. gracilis with the Austrian population studied by Foissner (1979). Vorticella gracilis forms a strongly supported phyloclade together with V. campanula, V. fusca and V. convallaria, while Vorticellides astyliformis and Vorticella microstoma branch in a separate, fully-supported clade that includes Astylozoon and Opisthonecta. The new genus Vorticellides comprises five small (usually < 60 μm), barrel-shaped species with two epistomial membranes: V. aquadulcis (Stokes, 1887) nov. comb., V. astyliformis (Foissner, 1981) nov. comb., V. platysoma (Stokes, 1887) nov. comb., V. infusionum (Dujardin, 1841) nov. comb., and V. (Spinivorticellides) echini (King, 1931) nov. comb. Two of these species are redescribed in the present study: V. astyliformis and V. aquadulcis, which is neotypified with a Costa Rican population. Pseudovorticella bromelicola nov. spec. differs from the congeners by the location of the two contractile vacuoles and the number of silverlines.

Morphology and SSU rRNA Gene Sequences of Three Marine Ciliates from Yellow Sea, China, Including One New Species, Uronema heteromarinum nov. spec. (Ciliophora, Scuticociliatida)

Abstract: 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.

Life Cycle, Morphology, Ontogenesis, and Phylogeny of Bromeliothrix metopoides nov. gen., nov. spec., a Peculiar Ciliate (Protista, Colpodea) from Tank Bromeliads (Bromeliaceae).

Abstract: 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 resting cysts of the theronts and trophonts are uniquely ellipsoidal, while the thick-walled cyst of the macrostome morph is globular. Reproduction occurs in freely motile condition either by binary fission or polytomy, producing a unique, motile “division chain” composed of four globular offspring, of which the central ones are connected by a curious, plug-like holdfast. Division is associated with a complete reorganization of the parental oral and somatic infraciliature. Stomatogenesis is merotelokinetal as in other members of the order Colpodida. The right polykinetid is generated by the rightmost postoral kinety, while the left polykinetid is produced by the two left postoral kineties and five left side kineties. The division in freely motile condition resembles the Exocolpodidae Foissner et al., 2002, to which Bromeliothrix is tentatively assigned, differing from Exocolpoda mainly by the formation of a macrostome morph and a division chain. Bromeliothrix has a ciliary and silverline pattern typical for members of the family Colpodidae. This matches the molecular classification which, however, hardly reflects the outstanding division and life cycle, suggesting some decoupling of morphological and molecular evolution. The specific morphological and ontogenetic traits of Bromeliothrix are interpreted as adaptations to the highly competitive habitat, favouring r-selected life strategies. Bromeliothrix metopoides is widespread in various tank bromeliads and can be easily cultivated in a wide variety of limnetic and terrestrial media. Thus, it remains obscure why this ciliate is restricted to tank bromeliads, i.e. did not occur in about 2,000 soil and freshwater samples investigated globally, including some 100 samples from Central and South America.

Tetrahymena spp. (Protista, Ciliophora) as Test Species in Rapid Multilevel Ecotoxicity Tests

Abstract: 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.

Ciliates of the Silent Valley National Park, India: Urostyloid Hypotrichs of the Region with a Note on the Habitat

Abstract: 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.

Testate amoebae of a monsoon tropical forest of South Vietnam.

Abstract: 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 over-wetting 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.

A Reinvestigation of Neokeronopsis Populations, Including the Description of N. asiatica nov. spec. (Ciliophora, Hypotricha)

Abstract: 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.

Redescription of Tintinnopsis parvula Jörgensen, 1912 (Ciliophora: Spirotrichea: Tintinnina), Including a Novel Lorica Matrix

Abstract: Tintinnopsis parvula Jorgensen, 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.

Environmental Controls on Pore Number in Hyalosphenia papilio: Implications for Paleoenvironmental Reconstruction

Abstract: 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.

Ultrastructure and Molecular Phylogeny of Mrazekia macrocyclopis sp. n. (Microsporidia, Mrazekiidae), a Microsporidian Parasite of Macrocyclops albidus (Jur.) (Crustacea, Copepoda)

Abstract: 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.

Two New Species of the Genus Stenamoeba Smirnov, Nassonova, Chao et Cavalier-Smith, 2007

Abstract: 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.

First Records of Trichodinid Ectoparasites (Ciliophora: Peritrichia) from Introduced Freshwater Fishes in Tasmania, Australia, with Comments on Pathogenicity

Abstract: 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) Sramek- Husek, 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.

Reassessment of the Putative Ciliate Fossils Eotintinnopsis, Wujiangella, and Yonyangella from the Neoproterozoic Doushantuo Formation in China

Abstract: Summary. 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.

Micro- and Macroscale Changes in Density and Diversity of Testate Amoebae of Tropical Montane Rain Forests of Southern Ecuador

Abstract: 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

Insights into the Phylogeny of the Genus Stentor (Heterotrichea, Ciliophora) with Special Emphasis on the Evolution of the Macronucleus Based on SSU rDNA Data

Abstract: 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.

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

Abstract: 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

Acanthamoeba in the Domestic Water Supply of Huntington, West Virginia, U.S.A.

Abstract: 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.

Nebela golemanskyi sp. nov., a New Sphagnicolous Testate Amoeba from Bulgaria (Amoebozoa: Arcellinida, Nebelidae)

Abstract: Summary. 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.

The Onset of Ciliate Populations in Newborn Foals

Abstract: 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.

Diversity and Distribution of Noctilucoid Dinoflagellates (Noctilucales, Dinophyceae) in the Open Mediterranean Sea

Abstract: 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.

Field and Laboratory Studies of Encysted and Trophic Stages of Naked Amoebae: Including a Perspective on Population Life Cycle Dynamics

Abstract: 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.

Morphological Redescriptions of Aspidisca magna Kahl, 1932 and A. leptaspis Fresenius, 1865 (Ciliophora, Euplotida), with Notes on Ontogenesis in A. magna

Abstract: 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 membrane are 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.

Ultrastructural Re-description of Henneguya piaractus (Myxozoa), a Parasite of the Freshwater Fish Piaractus mesopotamicus (Teleostei, Characidae) from the Paraguai River, Brazil

Abstract: 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.

Eimeriid coccidia (Apicomplexa: Eimeriidae) from geoemydid turtles (Testudines: Geoemydidae) with a description of six new species

Abstract: 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 flask-shaped sporocysts (11.1×5.7), with a Stieda body frequently connected with two to four filaments. 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 Siroký et Modrý, 2006 from the new host species-Cuora flavomarginata collected in China. Since many chelonians are critically endangered species, their parasite biodiversity will be lost following the collapse of their populations.

Molecular Cloning and Functional Characterization of Protein Phosphatase 2C of Two Scuticociliates-Uronema marinum and Miamiensis avidus (Ciliophora: Scuticociliatia)

Abstract: 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 Mg(superscript 2+) concentrations, and was not sensitive to okadaic acid, but was inhibited by sodium fluoride, EDTA or Ca(superscript 2+). 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.

Serotonin in Tetrahymena-How Does It Work?

Abstract: 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 serotonin-containing 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.

Ultrastructure and SSU rDNA Phylogeny of Paraphysomonas vestita (Stokes) De Saedeleer Isolated from Laguna de Bay, Philippines

Abstract: 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.

Isospora dendrocinclae n. sp. (Apicomplexa: Eimeriidae) from the White- chinned Woodcreeper (Dendrocincla merula) from South America

Abstract: 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.

Binary fission, telotroch formation and conjugation in Mantoscyphidia Jankowski, 1980 [Ciliophora: Peritrichia]

Abstract: 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 367 and 386% 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