Cyrtophorid Ciliates Research Articles

Taxonomic studies on Aegyria apoliva sp. nov. and Trithigmostoma cucullulus (Müller, 1786) Jankowski, 1967 (Ciliophora, Cyrtophoria) with phylogenetic analyses

The morphology, including the ciliary pattern, of two cyrtophorid ciliates, namely Aegyria apoliva sp. nov. and Trithigmostoma cucullulus (Müller, 1786) Jankowski, 1967, were investigated. They were isolated from coastal water off Qingdao and from an estuarine habitat in south China, respectively. Aegyria apoliva sp. nov. is characterized as following: body size 100–120 × 50–70 μm in vivo with dark pigment spot on anterior left part of cell; 48–69 somatic kineties; one preoral and four or five circumoral kineties; 9–13 transpodial segments; 26–40 nematodesmal rods; 6–10 contractile vacuoles. The Guangzhou population of Trithigmostoma cucullulus corresponds well with previously described populations, therefore only a brief morphological description is presented. Phylogenetic analysis based on small-subunit rRNA gene sequences data supports the establishment of the new species as well as the monophyly of both genera.

Morphology and Molecular Phylogeny of Three Cyrtophorid Ciliates (Protozoa, Ciliophora) from China, Including Two New Species, Chilodonella parauncinata sp. n. and Chlamydonella irregularis sp. n.

This study investigated the morphology and molecular characteristics of three interesting free-living cyrtophorid ciliates, including two new species, isolated from China: Chilodonella parauncinata sp. n. can be identified by its elongated body shape, with a sharp protrusion in the left anterior part, cell size ca. 60 × 25 μm in vivo, five right and 6-7 left kineties with kinetosomes densely arranged, and a curved cyrtos. Chlamydonella irregularis sp. n. differs from its congeners by the oval body shape, cell size 50-60 × 25-40 μm in vivo, irregular shape of macronucleus, 30-40 club-shaped ventral protuberances, and 17 somatic kineties. Two isolates of Chlamydonella derouxi Song, 2003, collected from an intertidal area in Shandong and a mangrove wetland in Guangdong respectively, correspond well with two previous descriptions, but differ in comprising more basal bodies in left and right equatorial fragments and in having more finger-like protuberances on the ventral side. Phylogenetic analyses based on the small subunit rRNA gene sequences showed that C. parauncinata sp. n. clustered with Chilodonella uncinata, but was a well-outlined species of the genus, and C. irregularis sp. n. and C. derouxi grouped in the family Lynchellidae with their congeners to form the monophyletic genus Chlamydonella.

Taxonomic studies on three marine ciliates from China, including a new species (Ciliophora, Cyrtophorida)

The present work investigates the living morphology and infraciliature of three marine cyrtophorid ciliates, which were isolated from Qingdao, China. Compared with its congeners, Orthotrochilia sinica spec. nov. can be distinguished by a combination of features: body slender and elliptical in outline, size about 50–60 × 20–25 μm in vivo, 18–21 somatic kineties, the length of the left perioral kinety treble the length of the right one, two ventrally located contractile vacuoles on the right side, and 25–32 nematodesmal rods. Based on current observations and the previous description, the diagnosis of Trochilioides tenuis (Deroux, 1976) Chen et al. 2011 is improved: cell size 30–40 × 20–35 μm in vivo, oval shaped in outline; consistently three right kineties, four left kineties and seven postoral kineties; a single contractile vacuole; marine habitat. A second species of Trochilioides, T. recta (Kahl, 1923) Chen et al. 2011 is re-described based on a Chinese population. Furthermore, a key to the identification of species of the genus Trochilioides whose infraciliature data are available is supplied, and Chlamydonyx trivialis (Fenchel, 1965) comb. nov. [basionym: Trochilioides trivialis Fenchel, 1965] is suggested.

Taxonomy of five species of cyrtophorids (Protozoa: Ciliophora) including consideration of the phylogeny of two new genera

Cyrtophorids are a specialized group of ciliated protozoa with multitudinous morphotypes. In the present work, the morphology and infraciliature of two new and three rarely known species, including two new genera of cyrtophorid ciliates, Heterohartmannula fangi gen. et sp. nov., Aporthotrochilia pulex (Deroux, 1976) gen. et comb. nov., Trochilia alveolata sp. nov., Trochochilodon flavus Deroux, 1976, and Hypocoma acinetarum Collin, 1907, are described. Heterohartmannula gen. nov. is mainly characterized by a combination of features: two circumoral kineties obliquely arranged, podite not surrounded by somatic kineties, and no distinct gap between left and right ciliary field. Aporthotrochilia gen. nov. is diagnosed mainly by: podite present, oral ciliature reduced to two fragments, several kinety fragments positioned on the right posterior of frontoventral kineties and several terminal fragments. Phylogenetic analyses based on the small subunit rRNA (SSU rRNA) gene sequences support the establishment of two new genera and indicate that Heterohartmannula is most closely related to Hartmannula, and Aporthotrochilia is basal to the Cyrtophoria-Chonotrichia clade. Trochilia alveolata sp. nov. differs from its congeners mainly by having a conspicuous alveolar layer. In addition, detailed live and infraciliature data of Hypocoma acinetarum and Trochochilodon flavus are supplied.

Morphology and infraciliature of two new marine ciliates, Paracyrtophoron tropicum nov. gen., nov. spec. and Aegyria rostellum nov. spec. (Ciliophora, Cyrtophorida), isolated from tropical waters in southern China

The morphology and infraciliature of two new marine cyrtophorid ciliates, Paracyrtophoron tropicum nov. gen., nov. spec. and Aegyria rostellum nov. spec., isolated from tropical waters in southern China, were investigated using live observation and protargol impregnation methods. Paracyrtophoron nov. gen. differs from the closely related Cyrtophoron by lack of fragment kinety at anterior ends of right somatic kineties and thigmotactic cilia in posterior portion of ventral surface, while from the well-defined Chlamydodon by lack of the cross-striped band around the periphery of the somatic field. Paracyrtophoron tropicum nov. spec., the type of the new genus, can be recognized by the combination of the following characters: cell size about 150–175×70–90μm in vivo; elliptical to kidney-shaped in outline, dorsoventrally flattened about 2.5:1; conspicuous cortical granules; one canal-like depression extending from postoral area to subcaudal region of cell; ca. 90 somatic kineties; 12–16 nematodesmal rods; one or two terminal fragments on dorsal side. Aegyria rostellum is characterized by the following features: size about 90–150×40–70μm in vivo, triangular or ear-shaped body with broad anterior end, having a rostriform structure and pigment spots, 56–63 somatic kineties, one preoral kinety, three or four circumoral kineties, and 32–42 nematodesmal rods. Based on previous and current studies, the definition for the genus Aegyria is updated: body dorsoventrally flattened; oral ciliature consisting of one preoral and several circumoral kineties; podite located in posterior ventral region and surrounded by somatic kineties; no obvious gap between right and left somatic kineties; postoral and left somatic kineties progressively shortened posteriorly from right to left. Additionally, two new combinations were proposed.

New contribution to the morphological taxonomy of three marine cyrtophorid ciliates from the Yellow Sea, China (Ciliophora: Cyrtophorida)

The morphology and infraciliature of three marine cyrtophorid ciliates, Dysteria lanceolata Claparede and Lachmann, 1859, Lynchella nordica Jankowski, 1968 and Chlamydonyx paucidentatus Deroux, 1976, collected from the coastal waters of Qingdao, China, were investigated using live observations and the protargol impregnation method. D. lanceolata was oval in body outline, about 65 x 45 mu m in vivo, with a subcaudally positioned podite, six to seven right kineties, two or three frontoventral kineties, and two ventral contractile vacuoles. The improved diagnosis for L. nordica and a key to all known Lynchella species are supplied. The rediscovery of C. paucidentatus enables us to accept its taxonomic identification (e.g., separation from a morphologically similar species Trochilioides recta). The genus Trochilioides Deroux, nov. gen., which was a nomen nudum according to ICZN (1999), is re-established.

Light microscopical observations on two marine dysteriid ciliates from Japan, including a description of Dysteria yagiui nov. spec. (Ciliophora, Cyrtophorida)

Two cyrtophorid ciliates, Dysteria yagiui nov. spec. and D. derouxi, were isolated from fish-farming waters at the New Fishing Port of Nagasaki, Japan. Their morphology and infraciliature were investigated using observation of living cells and protargol impregnation. D. yagiui nov. spec. is a large marine species distinguished from its congeners by the presence of 13 ventral kineties in the right field, of which six extend apically and 6–8 short fragments of kineties in the left equatorial field. D. derouxi has the characteristics previously described except that ciliates of this population possess nine ventral kineties in the right field, of which four extend apically.

Morphology and infraciliature of two marine species of Hartmannula (Protozoa, Ciliophora, Cyrtophorida), from scallop-farming waters off Qingdao (Tsingtao), China

The living morphology, infraciliature and silverline system of two marine cyrtophorid ciliates, Hartmannula derouxi nov. spec. and H. angustipilosa Deroux and Dragesco, 1968, collected from scallop-farming waters near Qingdao (Tsingtao), China, have been investigated. The new species is characterized by: size in vivo 60–120×30–70 µm, body long oval to elongate in outline, pellicle covered with a smooth, thin layer of gel-like substance; 42–53 ventral kineties, the rightmost 11–12 of which extend apically; about 30 nematodesmata; with about 25 ventrally located contractile vacuoles. Based on the Qingdao population and on previous descriptions, an improved diagnosis of Hartmannula angustipilosa is suggested: body oval in outline, size in vivo 40–80×20–50 µm; 20–28 ventral kineties, the rightmost five to six of which extend apically; about 10 nematodesmata; four to seven contractile vacuoles arranged in a longitudinal row on right side of cell. Additionally, the diagnosis of the genus Hartmannula is re-defined: dorsoventrally flattened Hartmannulidae with tail-shaped podite, oral structure consisting of three obliquely arranged fragments of dikinetids: one preoral and two circumoral; each nematodesmata tipped with one distinct tooth; somatic kineties progressively reduced from right to left posteriad; no gap between left and right field; podite subcaudally positioned, near but not surrounded by somatic kineties.

Morphology and Infraciliature of Some Cyrtophorid Ciliates (Protozoa, Ciliophora) from Freshwater and Soil

Summary Four little known cyrtophorid ciliates occurring in Austrian rivers and in soils from Australia and Madeira are described. Trithigmostoma srameki (Sramek-Husek, 1952) differs from its probably nearest relative, T. bavariensis (Kahl, 1931), by the limnetic habitat, the rounded posterior end of the right kinety field and the lower number of cytopharyngeal rods. The freshwater population of Odontochlamys alpestris Foissner, 1981 is very similar to the type population from an alpine soil. The apically positioned dorsal brush of Chilodonella convexa Kahl, 1931 consists of only four widely spaced cilia; it is thus transferred to the genus Odontochlamys. Gastronauta derouxi nov. spec. lives in mosses and soils and has about 7 groups of paired cilia along the anterior dorsal margin and a nonciliated postoral field.

Low molecular weight DNA in the heteromeric macronuclei of two cyrtophorid ciliates

Summary— The size range of the native DNA molecules in the heteromeric macronuclei of two cyrtophorid ciliates (Trithigmostoma cucullulus, Chilodonella uncinata) was mainly investigated by using agarose gel electrophoresis. Numerous bands superimposed on a continuous spectrum of molecular sizes between about 0.35 kb and 30 kb were resolved by conventional electrophoresis. Species‐specific banding patterns indicate a variation between species in the copy number of individual DNA fragments. A slight intra‐specific variability of banding patterns can exist. Electrophoretic distributions for two strains of T cucullulus were indeed found to differ by at least one more intense band (‘overamplified’ sequences?). Fractionation by contour‐clamped homogeneous electric field (CHEF) gel electrophoresis revealed that the size continum of macronuclear DNA molecules does not extend beyond 60–70 kb. The average size was estimated to be around 4 kb. Unresolved DNA fraction (> 1000 kb) accounted for less than 10% of the mass of cellular DNA entering CHEF gels. Macronuclear ribosomal DNA of each cyrtophorid species was identified by Southern hybridization with a Tetrahymena rDNA probe. The hybridization signal was observed on a single band of low molecular weight DNA. The corresponding size was close to 14.5 kb in Trithigmostoma and 15.5 kb in Chilodonella, which is about twice the size of monomeric rDNA in hypotrichous ciliates. We showed that S1 nuclease resistant duplexes wit half the length of the native rDNA can be formed by rapid renaturation of heat‐denatured molecules and hybridized with native rDNA. This strongly suggests that the nucleotide sequence of this rDNA is a large palindrome. Unlike the hypotrichs, macronuclear rDNA in cyrtophorids should be organized into palindromic dimers as in Tetrahymena species.