Showing papers in "Acta Protozoologica in 2017"

A Huge Diversity of Metopids (Ciliophora, Armophorea) in Soil from the Murray River Floodplain, Australia. II. Morphology and Morphogenesis of Lepidometopus platycephalus nov. gen., nov. spec.

Abstract: The morphology and morphogenesis of a new Australian metopid ciliate, Lepidometopus platycephalus nov. gen., nov. spec., were studied using live observation, various silver impregnation methods, scanning electron microscopy, and morphometry. The new genus is outstanding in having epicortical scales (lepidosomes) and a strongly flattened and distinctly projecting preoral dome. Diagnostic features of L. platycephalus include a small, reniform body carrying an elongated caudal cilium, about 11 ciliary rows, and an adoral zone composed of an average of 11 polykinetids. The morphogenesis of L. platycephalus matches data from other metopids in that (1) the body is drastically re-shaped, (2) the parental oral structures are reorganized but do not contribute to the daughter oral ciliature, (3) the opisthe’s adoral polykinetids originate pleurotelokinetally, (4) the opisthe’s paroral membrane is formed via re-arrangement of the posterior portion of the first two perizonal rows, and (5) the opisthe’s perizonal stripe is made by three parental perizonal rows and two dorsolateral ciliary rows. The morphogenetic data corroborate phylogenetic analyses in that caenomorphids are only superficially similar to metopids; metopids and clevelandellids are closely related; and litostomateans are the best candidates for a sister group of the metopid-clevelandellid assemblage within the SAL superclade.

A Study on Resting Cysts of an Oxytrichid Soil Ciliate, Rigidohymena quadrinucleata (Dragesco and Njine, 1971) Berger, 2011 (Ciliophora, Hypotrichia), including Notes on its Encystation and Excystation Process

Abstract: This is the first detailed study on the morphology of the resting cysts of an oxytrichid ciliate, Rigidohymena quadrinucleata. Resting cysts were investigated using light microscopy, SEM and TEM. The cyst wall is composed of four distinct layers (from inside to outside), namely the metacyst, the endocyst, the mesocyst and the ectocyst with spine-like protuberances. The cysts of R. quadrinucleata belong to the kinetosome-resorbing (KR) type, which is typical for oxytrichids. The processes of encystation and excystation were observed only in the light microscopy. During the encystation process, the trophic cell changes in shape and volume due to dehydration, four macronuclear nodules fuse into a compact mass, the ciliature is resorbed and cyst wall is formed. The most significant feature is surface ornamentation and yellowish color of resting cysts. We also focuse for the first time on excystation process of R. quadrinucleata. We identified two excystation modes: (i) standard and (ii) rare mode. The beginning of both excystation is characterised by the formation of excystation vacuole which helps the excysting cell to break the cyst wall. The specimen regenerates within a thin, flexible membrane. During the standard mode, the cell leaves the resting cyst in the membrane that is resorbed in the environment. During the rare mode, the excystation vacuole and the pressure of the regenerating cell break the transparent membrane that remains in the resting cyst. The results suggest that not only ciliate resting cysts, but also the excystation process is much more variable than what literature data indicate.

Morphological redescription and SSU rDNA-based phylogeny of two freshwater ciliates, Uronema nigricans and Lembadion lucens (Ciliophora, Oligohymenophorea), with discussion on the taxonomic status of Uronemita sinensis

Abstract: The morphology and phylogeny of two poorly known species, Uronema nigricans (Muller, 1786) Florentin, 1901 and Lembadion lucens (Maskell, 1887) Kahl, 1931, were respectively collected from a eutrophic freshwater river in Shenzhen and an oligotrophic lake in Zhanjiang (both in southern China) and investigated using standard taxonomic methods. The sampled population of Uronema nigricans was characterized by a cell size of 30–40 μm × 12–20 μm in vivo, an elongated elliptical outline with a prominent apical plate, and 13–15 somatic kineties. The sampled population of Lembadion lucens was characterized by a cell size of 45–80 μm × 20–50 μm in vivo, 25–35 somatic kineties, five or six caudal kinetosomes with cilia about 20 μm in length, and a single right-positioned contractile vacuole. The small subunit ribosomal RNA gene (SSU rDNA) of these species was sequenced and compared with those of their congeners to reveal nucleotide differences. The phylogenetic trees showed that the Shenzhen population of Uronema nigricans clusters with two other sequences under the name of “Uronema nigricans” (which are possibly misidentified) and then groups with Uronemita sinensis (Pan et al., 2013) Liu et al., 2016 with full support. Phylogenetic analyses indicated that genus Lembadion is monophyletic with full support provided by both Bayesian inference and maximum likelihood algorithms. Based on analyses of morphological and sequence data, Uronemita sinensis may represent a new genus between Uronema and Uronemita.

Exploring the diversity and ecology of testate amoebae in West Siberian peatlands

Abstract: Testate amoebae are valued for their functional significance and application as indicators of environmental conditions, particularly in peatland ecosystems. Research on testate amoebae has increased dramatically in recent years but there are still large parts of the world which have seen very little research. Here we consider testate amoeba communities of the West Siberian Lowland, the world’s largest peatland region and therefore one of the largest potential habitats for testate amoebae. Extensive sampling identified 89 taxa and showed that testate amoeba communities are structured by their physical and biological environment. We identified significant relationships between amoeba communities and both moisture content and vegetation composition. Despite the assemblages containing many widely-distributed species, some taxa considered typical of peatlands (e.g. Archerella flavum and Hyalosphenia papilio) were comparatively rare or absent, paralleling findings further south in Asia. We suggest that testate amoebae in this region deserve further study and may have useful applications in palaeoecological reconstruction and as bioindicators of the impacts of oil and gas extraction.

Constraints on phylogenetic interrelationships among four free-living Litostomatean Lineages inferred from 18S rRNA gene-ITS region sequences and secondary structure of the ITS2 molecule

Abstract: We investigated interrelationships between four free-living litostomatean lineages, using 18S rRNA gene and ITS region sequences as well as the secondary structure of the ITS2 molecules. Our phylogenetic analyses confirmed the deep split of free-living litostomateans into Rhynchostomatia and Haptoria represented here by Haptorida, Pleurostomatida, and Spathidiida. This bifurcation is also corroborated by the signature of the rhynchostomatian and haptorian ITS2 molecules. Specifically, the consensus stems of helices II and III are longer by one base pair in Rhynchostomatia, while the terminal loops of both helices are longer by one or two nucleotide/-s in Haptoria. A close relationship of Pleurostomatida and Haptorida is favored by quartet likelihood-mapping and supported by a 5’-AG vs. CU-3’ motif in the variable part of helix II and by two morphological apomorphies, i.e., meridionally extending somatic kineties and a non-three-rowed dorsal brush. Although monophyletic origin of Spathidiida is poorly supported in phylogenetic trees, the unique motif 5’-GA vs. UC-3’ present in the consensus helix II stem could be an important molecular synapomorphy of spathidiids, apart from the ancestrally anteriorly curved somatic kineties and the three-rowed dorsal brush. The peculiar family Pseudoholophryidae has very likely found its phylogenetic home among spathidiids, as an early branching lineage.

Response of Sphagnum Testate Amoebae to Drainage, Subsequent Re-wetting and Associated Changes in the Moss Carpet: Results from a Three Year Mesocosm Experiment

Abstract: Sphagnum peatlands represent a globally significant pool and sink of carbon but these functions are threatened by ongoing climate change. Testate amoebae are useful bioindicators of hydrological changes, but little experimental work has been done on the impact of water table changes on communities. Using a mesocosm experimental setting that was previously used to assess the impact of drought disturbance on communities and ecosystem processes with three contrasted water table positions: wet (–4 cm), intermediate (–15 cm) and dry (–25 cm), we studied the capacity of testate amoeba communities to recover when the water table was kept at –10 cm for all plots. The overall experiment lasted three years. We assessed the taxonomic and functional trait responses of testate amoeba communities. The selected traits were hypothesised to be correlated to moisture content (response traits: shell size, aperture position) or trophic role (effect traits: mixotrophy, aperture size controlling prey range). During the disturbance phase, the mixotrophic species Hyalosphenia papilio dominated the wet and intermediate plots, while the community shifted to a dominance of “dry indicators” (Corythion dubium, Nebela tincta, Cryptodifflugia oviformis) and corresponding traits (loss of mixotrophy, and dominance of smaller taxa with ventral or ventral-central aperture) in dry plots. During the recovery phase we observed two contrasted trends in the previously wet and intermediate plots: communities remained similar where the Sphagnum carpet remained intact but species and traits indicators of drier conditions increased in plots where it had degraded. In the former dry plots, indicators and traits of wet conditions increased by the end of the experiment. This is one of the first experiment simulating a disturbance and subsequent recovery in ex-situ mesocosms of Sphagnum peatland focusing on the response of testate amoebae community structure as well as functional traits to water table manipulation. The results generally confirmed that testate amoebae respond within a few months to hydrological changes and thus represent useful bioindicators for assessing current and past hydrological changes in Sphagnum peatlands.

Observations of Apparent Lorica Variability in Salpingacantha (Ciliophora: Tintinnida) in the Northern Pacific and Arctic Oceans

Abstract: Species identifications of tintinnid ciliates are based on characteristics of the lorica housing the ciliate cell. Molecular characterization of tintinnid ciliates has revealed the occurrence of cryptic species, genetically distinct forms with similar loricas, as well as polymorphic species in which genetically identical forms have distinct loricas. Among this latter category may be forms currently recognized as species of the genus Salpingacantha, erected by Kofoid and Campbell for forms originally described as varieties of species of Salpingella with ‘teeth’ on the margin of the lorica oral opening. Some workers have expressed the opinion that the genus is artificial and notably a recent molecular study suggested that Salpingella and Salpingacantha are likely synonyms. In this short communication we report on finding morphologically distinct loricas (containing ciliate cells) of Salpingacantha in single samples from stations in the North Pacific and Arctic Oceans in 2010, 2015 and 2016. We found up to 5 distinct Salpingacantha forms co-occurring, often with abundant Salpingella acuminata populations suggesting that some Salpingacantha species may be varieties of Salpingella acuminata. While we lack genetic data needed for definitive proof of polymorphism, here we document remarkable gradual gradients in morphology suggestive of polymorphism.

Rumen ciliate biota of domestic cattle (Bos taurus taurus) in Istanbul, Turkey and infraciliature of Metadinium medium (Entodiniomorphida, Ophryoscolecidae)

Abstract: The species composition and distribution of ciliates were investigated in the rumen contents of 15 domestic cattle (Bos taurus taurus L.) living in the European part of Istanbul, Turkey. Thirty-five species and 13 morphotypes belonging to 13 genera were identified. The density of rumen ciliates in cattle was 31.8 (± 21.3) × 104 cells ml−1, and the mean number of ciliate species per host was 12.9 ± 4.4. Of the ciliate species, Dasytricha ruminantium, Entodinium simulans, and Isotricha prostoma were the most abundant, each with a prevalence of 93.3%, whereas Diplodinium anisacanthum, D. dogieli, D. rangiferi, Enoploplastron triloricatum, Metadinium medium, and Ostracodinium munham were detected only in one animal (6.7% prevalence). Eodinium posterovesiculatum m. bilobosum and D. dogieli are new host records for cattle in Turkey. The infraciliature of M. medium (Entodiniomorphida, Ophryoscolecidae) was examined and detected for the first time. The buccal infraciliature of M. medium was composed of three polybrachykineties, a kinety loop, and paralabial kineties. A large dorso-adoral polybrachykinety, a gentle S-shaped curved vestibular polybrachykinety, and a kinety loop between the dorso-adoral polybrachykinety and adoral polybrachykinety were characteristics. Because of these features, M. medium-type buccal infraciliature was between the Ostracodinium gracile-type buccal infraciliature and the Ostracodinium mammosum-type buccal infraciliature.

Rat spleen in the course of Babesia microti invasion: histological and submicroscopic studies

Abstract: The course of babesiosis in humans is characterized by various intensity levels − from a subclinical level to the severe one − associated with multiple organ failure, which leads to death. The aim of this study was to evaluate the effect of 21-day and 6-month invasion of B. microti on Wistar rats spleen. Histological changes in the rats’ spleen were characterized by swelling of splenic tissue, especially the tissue adjacent to the capsule. In the structure of the white pulp in some rats, high concentrations of lymphocytes occurred. The boundary between the white pulp and red pulp was blurred. In the red pulp structure of rats, a lot of macrophages and extracellular deposits of bilirubin were present. The submicroscopic studies showed that the nuclear matrix was slightly shrunken. In the red pulp fragments of the damaged cells were located in the intercellular spaces. Near these areas, many thrombocytes were visible. The ultrastructural observation also revealed thickened endoplasmic reticulum membranes, local cellular swelling filled with amorphous substance, and digested erythrocytes. B. microti invasion affects the splenic morphology and ultrastructure in rats. The immunological hyperactivity and signs of inflammation indicate an important role of spleen in a fight against parasites.

Morphology and Molecular Phylogeny of Pseudocyrtohymenides lacunae nov. gen., nov. spec. (Ciliophora: Oxytrichidae) from South Korea

Abstract: We collected an 18-cirri oxytrichid ciliate from the brackish lagoon Songjiho, South Korea, in March 2012. Based on analyses of morphological and molecular attributes, we conclude that it is new genus and species. Pseudocyrtohymenides lacunae nov. gen., nov. spec. has similar morphological attributes to the genus Pseudocyrtohymena, however, the former species lacks caudal cirri. The sequence similarity of the nuclear small subunit ribosomal RNA (SSU rRNA) gene was 99.4% (10 nt difference) between Pseudocyrtohymenides lacunae and Pseudocyrtohymena koreana (type species).

Taxonomic and Morphogenetic Description of the Freshwater Ciliate Aponotohymena isoaustralis n. sp. (Ciliophora; Oxytrichidae) Isolated from Sanjay Lake, Delhi, India

Abstract: Morphology, morphogenesis and molecular phylogeny of a freshwater oxytrichid ciliate, Aponotohymena isoaustralis n. sp. collected from Sanjay Lake (28°36′51″N, 77°18′14″E), Delhi, India, were studied. The described species is characterized by a flexible body, with body size (in vivo) of about 148 × 46 µm and yellowish green cortical granules. Morphological characters exhibit: undulating membranes in Notohymena–pattern; two macronuclei and absence of micronucleus (amicronucleate); about 36 adoral membranelles; 18 frontoventral-transverse (FVT) cirri; one right and one left marginal row separated posteriorly; 6 dorsal rows; 7 caudal cirri arranged in 2 + 2 + 3 pattern (constant). In the present study, a detailed description of all the developmental stages is also provided. Prominent distinguishing features of the new species are the absence of micronucleus, 7 caudal cirri (constant), yellowish green cortical granules aligned along the margins and irregularly distributed throughout the cell. They may also be randomly concentrated as clusters along the left margin and posterior end of the cell. Molecular phylogeny based on small subunit rDNA sequence data suggests sister relationship of Aponotohymena isoaustralis n. sp. with Notohymena apoaustralis and Aponotohymena australis (Notohymena australis) which cluster in a clade with Paraurostyla weissei and Paraurostyla coronata. Further analysis of nucleotide sequence of SSU rDNA also suggests that A. isoaustralis n. sp. is distinct from the type species A. australis.

The Impacts of Crustacean Zooplankton on a Natural Ciliate Community: a Short-term Incubation Experiment

Abstract: Direct and indirect effects of crustacean zooplankton (cladocerans and copepods) are important regulators of ciliate communities, especially in eutrophic systems. However, it is not clear whether pseudodiaptomids (e.g., Schmackeria), one of the dominant calanoid copepods in Chinese lakes, effectively impacts natural ciliate communities. The impacts of small-bodied cladocerans (e.g., Bosmina) on ciliates are also controversial. We performed an incubation experiment using winter lake water from Lake Chaohu to assess the structuring effects that crustacean zooplankton have on natural ciliate populations. The presence and absence of cladocerans (Bosmina sp.) and copepods (Schmackeria inopinus) were alternated in four treatments. Both Bosmina sp. and Schmackeria inopinus had substantial impacts on ciliate abundance, biomass, and community structure. The response of ciliates was different in the presence of Bosmina sp. compared with Schmackeria inopinus and varied among categories such as the ciliate population, relative body size and functional feeding group. Our results also highlight the importance of interference and exploitative competition among metazooplankton groups.

Allovahlkampfia minuta nov. sp., (Acrasidae, Heterolobosea, Excavata) a new soil amoeba at the boundary of the acrasid cellular slime moulds.

Abstract: We report the isolation of a new species of Allovahlkampfia, a small cyst-forming heterolobosean soil amoeba. Phylogenetic analysis of the 18S rDNA and the internal transcribed spacers indicates that Allovahlkampfia is more closely related to the acrasids than to other heterolobosean groups and indicates that the new strain (GF1) groups with Allovahlkampfia tibetiensis and A. nederlandiensis despite being significantly smaller than these and any other described Allovahlkampfia species. GF1 forms aggregated cyst masses similar to the early stages of Acrasis sorocarp development, in agreement with the view that it shares ancestry with the acrasids. Time-lapse video microscopy reveals that trophozoites are attracted to individuals that have already begun to encyst or that have formed cysts. Although some members of the genus are known to be pathogenic the strain GF1 does not grow above 28oC nor at elevated osmotic conditions, indicating that it is unlikely to be a pathogen.

Description of a new brackish water ciliate, Uronychia xinjiangensis n. sp. (Ciliophora, Euplotida) based on morphology, morphogenesis and molecular phylogeny

Abstract: A brackish water euplotid ciliate, Uronychia xinjiangensis n. sp., was discovered in a ditch in Yuli County, Xinjiang, China. Its morphology, ciliature and morphogenesis were investigated based on specimens examined in vivo and following protargol staining. The new species is characterized by the posterior part of the adoral zone composed of three membranelles, which has never been seen in all other known congeners. Other morphologic features include: (i) body oval-shaped, with conspicuous right anterior spur-like protrusion; (ii)size in vivo 60–90 × 40–68 μm; (iii) two macronuclear nodules; (iv) four frontal, two ventral, five transverse, three left marginal and three caudal cirri. Its morphogenesis proceeds in a usual way, except that the oral primordium forms only three proximal membranelles rather than four proximal membranelles within congeners. The small subunit rRNA gene of the new species (GenBank accession number: KX147287) comprises 1723 bp and 44.63% GC content, and differs by 0.12–1.81% from those of congeners. Phylogenetic analyses based on SSU rRNA gene sequence data reveal that Uronychia xinjiangensis n. sp. clusters with other Uronychia species with full support, which supports the monophyly of the genus Uronychia Stein, 1859.

Isolation of Thermotolerant Pathogenic Naegleria australiensis from Diverse Water Resources Including Household Drinking Water in Pakistan

Abstract: Naegleria is well recognized for primary amoebic meningoencephalitis which always results into death. To date there is not a single report demonstrating molecular identification of Naegleria from water resources of Pakistan thus the aim of the proposed study. Here, in total 135 various water samples (like domestic tap water, municipal water, sea water, well water, tube well water, canal water, boring water, sewage water, lake water and stream water) were collected across Pakistan and evaluated for Naegleria species. Naegleria australiensis (pathogenic) and Naegleria lovaniensis (non pathogenic) were isolated on non nutrient agar plates and were further identified by PCR and sequencing. To best of our knowledge we have described for the first time the isolation and molecular identification of thermotolerant pathogenic and non pathogenic Naegleria species from diverse water samples including drinking water across Pakistan. The presence of pathogenic Naegleria species in diverse water samples may add the health threat to the community.

Achradina pulchra, a Unique Dinoflagellate (Amphilothales, Dinophyceae) with a Radiolarian-like Endoskeleton of Celestite (Strontium Sulfate)

Abstract: We examined the planktonic dinoflagellate Achradina pulchra by light and scanning electron microscopies from the South and North Atlantic oceans. The basket-like skeleton has been interpreted as a thick cell covering or pellicle of organic composition, or as a siliceous endoskeleton. The skeleton of Achradina is known only from fresh material, being absent in preserved samples, sediments or the fossil record. X-ray microanalysis revealed that the endoskeleton of Achradina is composed of celestite (strontium sulfate) with traces of barite (barium sulfate), two minerals that readily dissolve after cell death. To date, Acantharia and polycystine radiolarians (Retaria) were the only known organisms with a skeleton of this composition. We can now add a dinoflagellate to the list of such mineralized skeletons, which influence on the biogeochemical fluxes of strontium and barium in the oceans. Moreover, we provided the first molecular data for a skeleton-bearing dinoflagellate. Molecular phylogeny based on the SSU rRNA gene sequences revealed that Achradina and several environmental clones branched as an independent lineage within the short-branching dinokaryotic dinoflagellates. To date, seven clades of dinokaryotic dinoflagellates are known living as symbionts in the endoplasm of Acantharia and polycystine radiolarians. Because celestite built skeletons were unknown outside radiolarians, we suggested that the ancestors of Achradina acquired the genes implicated in the deposition of strontium and barium from radiolarian hosts though a horizontal gene transfer event between microbial eukaryotes.

Taxonomical reinvestigation of the colepid species Pinacocoleps pulcher (Spiegel, 1926) Foissner et al., 2008 (Ciliophora: Prorodontida: Colepidae)

Abstract: Brackish water populations of Pinacocoleps pulcher were collected from a lagoon in Korea. This species has never been described using silver impregnation and nuclear small subunit ribosomal RNA (SSU rRNA) gene. In the present study, we investigated the morphological and molecular attributes of P. pulcher using standard methods. The morphology was studied based on observations of live materials, silver-impregnated preparations, and scanning electron microscopy. The morphological characteristics are as follows: body size 80–90 × 40–50 µm in vivo, shape broadly ellipsoidal, body cross-section ellipsoidal, about seven anterior spines and about seven posterior spines, approximately 21 somatic ciliary rows, one macronucleus and one micronucleus, and a single caudal cilium. The SSU rRNA gene tree supports a sister relationship of P. pulcher to the genus Apocoleps, not P. tesselatus.

Improvement of Silver Impregnation Technique Using in Situ Synthesized Protargol

Abstract: An improved impregnation method for ciliates has been described with a new formulation for silver proteinate synthesized in situ, that avoids necessary its long-time laboratory synthesis or use of expensive commercial protargol. Compared to conventional techniques, the proposed protocol is more time-saving, reduces the consumption of chemicals and excludes some hazardous ones (e.g. xylene). Structures that are impregnated such as nuclear apparatus, infraciliature, cortical and cytoplasmic microtubules are stained almost identical compared to other protargol methods. Advantages of this method allow us to merge it successfully with ecological quantitative studies of various natural communities of ciliates and provide correct identification of species during such investigations.

Peculiarities of Trypanosoma rangeli KP1(-) Strains Isolated from the Wild Rodent Phyllomys dasythrix (Santa Catarina, Brazil): Comparisons with T. rangeli KP1(+) strains and Trypanosoma lewisi (Kinetoplastea, Trypanosomatidae)

Abstract: Two KP1(–) strains of Trypanosoma rangeli (SC-58, SC-61) isolated from the wild rodent Phyllomys dasythrix from Santa Catarina (Brazil) were compared with some KP1(+) reference stocks from different Latin America countries, and also with Trypanosoma lewisi. The strains were analyzed by some morphological and biological features, and by biochemical and molecular techniques. The mean total length (TL) of the bloodstream trypomastigotes of T. rangeli varied between 31.3–33.0 μm, and those of T. lewisi (adult forms) was 28.2 μm, values within the variation known for each species. In T. rangeli KP1(+) and T. lewisi, the nucleus was located in the anterior portion of the body, with nuclear indexes (NI) ≥ 1.2, as typically described for both species. Differently, most trypomastigotes of the KP1(–) stocks presented NI ≤ 1.0. Another striking feature of the KP1(–) strains was their very fastidiously growth in axenic cultures when compared with the KP1(+) stocks and T. lewisi. Three isoenzyme loci (MDH, IDH and PGM) clearly distinguished T. rangeli and T. lewisi, and the distinction between the KP1(+) and KP1(–) strains was possible at MDH, PGM and GPI loci. All T. rangeli strains presented the typical 760 bp amplicon derived from their KP2 minicircles. However, the KP3 products of the KP1(+) strains were a single large band (~330bp), whereas those of the KP1(–) had two distinct bands (350 and 300 bp). T. lewisi presented 700 and 400 bp amplicons, as previously reported. The peculiarities of T. rangeli isolates from P. dasythrix corroborate a possible speciation process within this taxon.

The Systematic Studies on the Hypotrich Ciliate, Tachysoma pellionellum (Müller, 1773) Borror, 1972 (Protozoa, Ciliophora) Based on Integrative Approaches: Morphology, Morphogenesis and Molecular Phylogenetic Analyses

Abstract: Tachysoma pellionellum Stokes, 1887, a freshwater ciliate isolated from Stone Mountain State Park, North Carolina, was studied in vivo and after staining with protargol. The population was characterized mainly by having the typical 18 frontal-ventral-transverse cirri; posterior ends of left and right marginal rows not confluent; five dorsal kineties and one dorsomarginal kinety; two macronuclear nodules near left cell margin with one or two micronuclei between them; contractile vacuole located at mid-body near left margin. Morphogenesis is characterized as follows: (1) in the proter, the parental adoral zone of membranelles is retained completely; (2) 18 frontal-ventral-transverse cirri are derived from the anlage of the undulating membrane and the five streaks of the frontal-ventral-transverse anlagen; (3) marginal rows develop intrakinetally; (4) anlagen of dorsal kineties 1, 2 and 4 develop in the parental structure and anlagen of dorsal kineties 2 and 4 fragment in the posterior region forming anlagen of dorsal kineties 3 and 5; (5) only one dorsomarginal kinety formed; (6) the two macronuclear nodules fuse into a single mass, which then divides. Phylogenetic analyses based on sequences of the gene coding for SSU RNA revealed a close relationship between T. pellionellum and the Oxytricha clade, both of which grouped with Kleinstyla dorsicirrata and Heterourosomoida lanceolata.

Testate Amoeba Diversity of a Poor Fen on Mineral Soil in the Hilly Area of Central Honshu, Japan

Abstract: We present a short note on the species composition of testate amoebae in a poor fen on mineral soil near the Pacific Coast in the hilly area of Central Honshu, Japan. In total 45 species and subspecific taxa belonged to 21 genera and 14 families of testate amoebae were recorded. Eight species and nine subspecies are newly recorded from Japan. However, most species from the list can be considered as distributed worldwide and associated mostly to oligotrophic/acid Sphagnum conditions.

Distribution and occurrence of the neogregarine pathogen, Ophryocystis anatoliensis (Apicomplexa) in populations of Chrysomela populi L. (Coleoptera: Chrysomelidae)

Abstract: Chrysomela populi L. (Coleoptera; Chrysomelidae) is one of the most serious pests affecting poplars. Chemical control is the most widely known suppressive method against this pest. This method is not acceptable in urban forests because of their proximity to people. Entomopathogenic organisms are environmentally friendly control agents and suppress the pest populations under natural conditions. In the present study, the occurrence and distribution of a new entomopathogenic protist, a neogregarine, Ophryocystis anatoliensis (Apicomplexa) in C. populi populations and a member of the family Chrysomelidae is presented for the first time. In total, 90 of 2185 C. populi adults and larvae collected from 16 localities during three years (from 2013 to 2015) were found to be infected by this pathogen. Neogregarine infection was observed in 14 of 16 investigated C. populi populations. The infection was variable between the populations and years. These results confirm that the neogregarine pathogen has a high dispersal potential through the C. populi populations and can be an effective natural biological suppressing factor on the pest populations.

Mobiline peritrichs (Ciliophora) collected from the gills of African limpets

Abstract: Members of the Urceolariidae Dujardin, 1941 have been found associated with a wide variety of invertebrate hosts from freshwater and marine habitats. Five species have been described from molluscan hosts from Europe and America. This paper deals with an urceolariid (Leiotrocha Fabre-Domergue, 1888) collected from the gills of Cellana radiata capensis (Gmelin, 1791) and Scutellastra exusta (Reeve, 1854) from the east coast of South Africa, as well as Patella depressa Pennant, 1777 and Cymbula safiana (Lamarck, 1891) from the bulge (west coast) of Africa. A higher prevalence was found on C. radiata capensis (89%) and P. depressa (72%) compared to the other two hosts. The urceolariid collected from the African limpets was identified as L. patellae (Cuenot, 1891). This is the first record of an urceolariid from any African hosts, including representatives of the Mollusca. Five urceolariid species were identified and described from gastropods, i.e. L. patellae Cuenot, 1891, U. karyolobia Hirshfield, 1949, U. cellanae Suzuki, 1950, U. viridis Richards, 1971 and U. parakorschelti Irwin, Sabetrasekh and Lynn, 2017. Motivation is provided why U. cellanae and U. viridis should be reallocated to the genus Leiotrocha, and U. karyolobia not. The taxonomic validity of the recent description of U. parakorschelti from limpets is commented on.

Cortical Localization of α- and γ-Tubulin and the Assembly of Cortical Microtubule Cytoskeleton in Hypotrichous Ciliate Euplotes eurystomus

Abstract: This study aimed to investigate the assembly characteristics of ciliature and cortical microtubules and the localization of tubulins in different depths and regions of the cortex. The hypotrichous ciliates have closely arranged cilia and a highly complex microtubular system. Direct fluorescence and immunofluorescence labeling were used to observe ciliary organelles and cortical microtubular cytoskeleton in Euplotes eurystomus. An immunofluorescence analysis demonstrated that α-tubulin localized to the ventral and dorsal ciliary organelles and their associated microtubules, while γ-tubulin localized to the basal bodies of ciliary organelles, macronuclear membrane, and excretory pore of a contractile vacuole in the interphase. A direct fluorescence analysis showed that the ciliature and cortical microtubules in the deep cortex were more clearly marked by fluorescent taxoid (FLUTAX). Interestingly, α- and γ-tubulins also colocalized to the ringlike ciliary base–associated microtubules of dorsal kineties. The short microtubular bundles between the bases of transverse cirri could be marked by FLUTAX and γ-tubulin rather than α-tubulin, suggesting that tubulins in cortical microtubules in E. eurystomus varied, and the differentiation of cortical microtubules in the hypotrichous ciliate tended to be versatile. Also, during morphogenesis, γ-tubulin also localized to the base of ciliary primordium, where new basal bodies were formed, suggesting that the endocellular position of γ-tubulin in ciliates was related to basal bodies and regulated by the cell cycle. This study might help understand the assembly characteristics and tubulin composition of microtubules in different depths and regions of the cortex in hypotrichous ciliate E. eurystomus.

Photoresponse in the Ciliated Protozoan Colpoda cucullus

Abstract: We found that vegetative cells of Colpoda cucullus Nag-1 accumulated in shaded areas of a container when grown in the laboratory and then formed resting cysts. The photodispersal (negative photoaccumulation) of C. cucullus was mediated, at least in part, by a difference in forward swimming velocity between the illuminated region and the shaded area of the Petri dish (motion slowed or stopped in the shaded area). When C. cucullus was stimulated by continuous light irradiation, the forward swimming velocity increased and reached a steady state within 10 s. When the light intensity decreased, the forward swimming velocity gradually decreased, and eventually returned to its original level for approximately 1 min. The action spectrum of the photokinetic response (steady-state swimming acceleration driven by continuous light stimulation) implies the involvement of blue light receptors.

Actinomycin D as an Epimutagen in Protists

Abstract: A previously unrecorded property of actinomycin D, a well-known antibiotic, was discovered in the course of long-term genetic research on the amoeba Amoeba proteus and the ciliate Dileptus anser. In these protists actinomycin D can induce an unusual type of hereditary variation, which we refer to as the inheritable destabilization of characters. A number of features indicate that this variation is epigenetic, that is, not caused by mutations in the DNA. Therefore, actinomycin D may be considered as an inducer of epigenetic inheritable changes, in other words, as an epimutagen.

Low-level genetic diversity of opalinid morphotypes from the digestive tract of Hoplobatrachus rugulosus (Batrachia, Amphibia) in Thailand

Abstract: Opaline is an unusual group of protists, characterized by the presence of flagella covering their whole body. They reside in the intestinal tracts of various animals, most notably amphibians. While there is a wealth of data regarding the morphological features of opalines, molecular data are extremely sparse. Consequently, the extent of diversity of this understudied group remains unknown. Here, we examine opalines from the intestinal tract of the amphibian Hoplobatrachus rugulosus in Thailand. We provide micrographs obtained from light and scanning electron microscopy of various opalinid morphotypes. Furthermore, we enrich the database of opaline sequences by providing new molecular data of the small subunit ribosomal DNA gene of these species. In our phylogenetic analyses, the newly derived sequences form a cluster sister to Protoopalina.