Morphology of Three Species of Amphileptus (Protozoa,Ciliophora, Pleurostomatida) from the South China Sea,with Note on Phylogeny of A. dragescoi sp. n.

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

Re-establishment of the cyrtophorid genus Coeloperix Deroux,nov. gen., with a description of Coeloperix sleighi nov. spec. (Protozoa,Ciliophora, Cyrtophorida)

The cyrtophorid genus Coeloperix, which has remained invalid for over 20 years, is re-established. This taxon is characterized by Lynchellids without podites on the ventral side; somatic kineties making no noticeable naked gap between left and right areas; pre- and post-oral kineties completely separated; two terminal fragments; perioral kineties consisting of one continuous anterior and two detached posterior rows; with cross-striated band around perimeter between ventral and dorsal surfaces. Based on this definition, two nominal species formerly placed in the invalid genus have been included again in Coeloperix: Coeloperix dirempta (Deroux, 1970) nov. comb. [synonym: Lynchella dirempta; Deroux, 1970], C. aspidisciformis (Kahl, 1933) nov. comb. [syn. Lynchella aspidisciformis; Kahl, 1933]. Another two morphotypes C. eforiana (Tucolesco, 1962) nov. comb. [syn. Lynchella eforiana; Tucolesco, 1962] and C. lynchelliformis (Borror, 1972) nov. comb. [syn. Chlamydodon lynchelliformis; Borro, 1972] have been transferred into the new genus. The morphology of living cells and infraciliature of a new species, C. sleighi nov. spec., isolated from the coastal area of China, have been investigated. It is diagnosed by: size about 40×30 μm in vivo; consistently 4 preoral and 15–16 postoral kineties; 12–16 nematodesmata; cross-striated band with two separations in the equatorial area; 3–4 (usually 3) finger-like tentacles on the ventral side; macronucleus ellipsoidal; two contractile vacuoles diagonally located; marine habitat.     

Three New Loxophyllum Species (Ciliophora: Pleurostomatida) from China with a Brief Review of the Marine and Brackish Loxophyllum Species

Recent studies indicate that there is a high diversity of pleurostomatid ciliates in the coastal waters of China. Here, three new congeners of Loxophyllum, L. caudatum sp. n., L. rugosum sp. n., and L. chinense sp. n., are described following observations of live cells and protargol‐impregnated specimens. All three species usually have two macronuclear nodules and prominent warts along the dorsal margin formed by clustered extrusomes. In addition, L. caudatum sp. n. is characterized by its long conspicuous tail, dot‐like cortical granules, 4 or 5 left and 9 or 10 right kineties, and a single subterminal contractile vacuole. Loxophyllum rugosum sp. n. is distinguished by possessing three prominent ridges on the left side, 7–11 right and 5–7 left kineties. Loxophyllum chinense sp. n. is characterized by having several contractile vacuoles distributed along the ventral margin, 13–18 right and 6–8 left kineties. The small subunit ribosomal DNA (SSU rDNA) sequence similarities among six congeners range from 96.46% to 99.94%. Phylogenetic trees based on the SSU rDNA sequences indicate that all Loxophyllum spp. form a well‐supported monophyletic group. A brief review of the marine and brackish Loxophyllum species is supplied and one new combination, Litonotus multiplicatus (Kahl 1931) comb. n. (basionym Loxophyllum multiplicatum Kahl 1931), and one new name, Litonotus dragescoi nom. n. (basionym L. fasciolatus Dragesco 1966), are suggested.     

Microscopical observations on four marine Dysteria species (Ciliophora, Cyrtophorida)

Four interesting strains of marine ciliates belonging to the genus Dysteria, collected from the coastal area of Qingdao, China, were investigated using living observations and silver impregnation methods. New data are supplied in redefinitions of three poorly known species, all of which had two contractile vacuoles. D. crassipes Claparède and Lachmann, 1859 has a rectangular body about 65 x 35 microm in vivo, with a podite subcaudal on the ventral side and a dorsal spine on some specimens; it has four right kineties, the rightmost two of which extend dorso-apically; both plates of examined specimens had a covering of ectosymbiotic bacteria. D. semilunaris (Gourret and Roeser, 1886) Kahl, 1931 has an oval body about 30 x 16 microm in vivo, with a caudal podite and a groove on the left plate; it also has four right kineties, the rightmost two of which extend dorso-apically. D. pectinata (Nowlin, 1913) Kahl, 1931 also has an oval body and caudal podite, but is larger at about 85 x 40 microm in vivo; it has seven right kineties, the rightmost two of which extend dorso-apically and the leftmost one is short and posterior. The fourth strain was D. brasiliensis Faria et al., 1922, which was found to vary in both shape and the presence or absence of a dorsal spine, it also hosts numerous rod-shaped ectosymbiotic bacteria on both plates of the cell. Based on information available, a key to the marine species that have been investigated by silver impregnation is updated.     

Two new marine pleurostomatid ciliates from China,Amphileptus gui nov. spec. and Amphileptus yuianus nov. spec. (Ciliophora,Pleurostomatida)

The morphology and infraciliature of two pleurostomatid ciliates, Amphileptus gui nov. spec. and A. yuianus nov. spec., collected from mariculture ponds near Qingdao (Tsingtao), China, were investigated using living observations and the protargol impregnation method. These new species are distinguished from their congeners by a combination of characters including their marine habitat and the presence of an apical group of densely packed extrusomes. Amphileptus gui nov. spec. differs from A. yuianus nov. spec. mainly in the number of contractile vacuoles (3–7 vs. 1), the shape of extrusomes (thin bar-like vs. clavate), and the number of left and right somatic kineties (7–11 and 37–50 vs. 4 and 18–22).     

New contributions to the biodiversity of ciliates (Protozoa,Ciliophora) from Antarctica,including a description of <Emphasis Type="Italic">Gastronauta multistriata</Emphasis> nov. spec.

Antarctica is a remote and isolated biotope which makes it an ideal location for studying new and endemic species. Since there is little literature available on the diversity of ciliates in this area, a taxonomic survey of ciliates from melt-water of Collins glacier, King George Island, was carried out from January to March 2006. As a result, the morphology and infraciliature of five ciliates, including one new species, are described using live observations and silver staining: Gastronauta multistriata nov. spec., Neokeronopsis asiatica Foissner et al., 2010, Paraholosticha muscicola Kahl, 1932, Oxytricha sp., and Cyclidium glaucoma Müller, 1786. Gastronauta multistriata nov. spec. is distinguished from its congeners by the following combination of characters: cell size in vivo on average 80 × 40 μm; 5–9 kineties in left ciliary field; 18–23 kineties in right ciliary field, including 10–12 postoral kineties; 7–10 preoral kineties; dorsal brush along anterior dorsal margin, consisting of 5–8 groups of basal bodies. The only minor differences between the current population of N. asiatica and a previously described Antarctic population are the numbers of caudal cirri (6–10 vs. 8–15) and dorsal kineties (11–13 vs. 12–18). Paraholosticha sterkii is synonymised with P. muscicola. The Antarctic population of C. glaucoma corresponds well with a former population from China, the only difference being the number of kinetids in SK _n (11–17 vs. 9–11). This work will contribute to the understanding of ciliate diversity in this little studied area.     

Morphology,Morphogenesis, and Molecular Phylogeny of Anteholosticha multicirrata n. sp. (Ciliophora,Spirotrichea) with a Note on Morphogenesis of A. pulchra (Kahl, 1932) Berger, 2003

Two marine urostylid ciliates, Anteholosticha multicirrata n. sp. and Anteholosticha pulchra (Kahl, 1932) Berger, 2003, were collected from South Korea. These species were identified based on morphology, morphogenesis, and SSU rRNA gene sequence comparison. Anteholosticha multicirrata n. sp. is characterized by the following features: body size 90–125 × 30–45 μm in vivo, shape slender to ellipsoidal in outline, with yellow‐greenish cortical granules distributed along and between dorsal kineties and cirri; single contractile vacuole positioned on left at mid‐body; three frontal, five to seven frontoterminal, one buccal, one to two pretransverse and four to six transverse cirri; three complete dorsal kineties; one left and one right marginal cirral row; about 117 macronuclear nodules; and three to four micronuclei observed during morphogenesis. In addition, based on the observations of morphogenesis, we found that A. pulchra has pretransverse cirri, which were not described in detail in previous studies. Nuclear small subunit ribosomal RNA (SSU rRNA) gene was used to analyse their phylogenetic relationship, and the gene tree supports that the genus Anteholosticha is a highly polyphyletic group.     

Two New Brackish Ciliates,Amphileptus spiculatus sp. n. and A. bellus sp. n. from Mangrove Wetlands in Southern China,with Notes on the Molecular Phylogeny of the Family Amphileptidae (Protozoa,Ciliophora, Pleurostomatida)

Two new brackish pleurostomatid ciliates, Amphileptus spiculatus sp. n. and A. bellus sp. n. were collected from mangrove wetlands of southern China and their morphology and molecular phylogeny were studied. Amphileptus spiculatus sp. n. can be distinguished from congeners by the presence of 11–14 right and 6–8 left kineties, two macronuclear nodules and a conspicuous beak‐like anterior body end. Amphileptus bellus sp. n. is characterized by the presence of 2–4 macronuclear nodules, 31–35 right and 6 or 7 left kineties and two types of extrusomes. Phylogenetic analyses based on SSU rDNA sequences data indicate that the family Amphileptidae is paraphyletic.     

Morphology and Phylogeny of Three Pleuronema Species (Ciliophora,Scuticociliatia) from Hangzhou Bay,China, with Description of Two New Species,P. binucleatum n. sp. and P. parawiackowskii n. sp.

The morphology and phylogeny of Pleuronema binucleatum n. sp., P. parawiackowskii n. sp., and P. marinum Dujardin 1841, collected from Hangzhou Bay estuary, China, were investigated using standard methods. Pleuronema binucleatum n. sp. can be identified by possessing about 90–120 × 35–50 μm cell size in vivo, reniform body outline, two macronuclei, six to eight preoral kineties, 32–41 somatic kineties, and posterior end of the anterior fragment of membranelle 2 (M2a) hook‐like. Pleuronema parawiackowskii n. sp. is characterized by the combination of the following characters: body size about 60–90 × 20–40 μm in vivo, elliptical in outline, four to eight preoral kineties, 20–29 somatic kineties, posterior portion of the M2a slightly curved but nonhooked, and single macronucleus sausage‐like. After comparison with other populations of P. marinum, it is suggested that many misidentifications exist in previous studies. And an improved diagnosis of P. marinum was supplied: cell about 95–180 μm long, elliptical in outline; 2–4 preoral kineties and 53–70 somatic kineties; both membranelle 1 and membranelle 3 three‐rowed; posterior end of the M2a straight; single contractile vacuole characteristically positioned near mid‐body. The small subunit rRNA genes of three forms were sequenced. Phylogenetic analyses indicate that the monophyly of the genus Pleuronema is still not supported.     

Morphology,morphogenesis and molecular phylogeny of a freshwater ciliate,Monomicrocaryon euglenivorum euglenivorum (Ciliophora,Oxytrichidae)

The morphology, morphogenesis and molecular phylogeny of the oxytrichid ciliate, Monomicrocaryon euglenivorum euglenivorum (Kahl, 1932) Foissner, 2016, isolated from freshwater in a seaside park, Guangzhou, China, were investigated. Monomicrocaryon euglenivorum euglenivorum can be recognized as follows: caudal cirri in midline of body; dorsal kinety 1 without a one-kinetid-wide gap; transverse cirri acicular or rod-shaped with a fringed distal end; right marginal row commences at level of buccal vertex or anterior to buccal vertex. The main events during binary fission are as follows: (1) the proter retains the parental adoral zone of membranelles entirely; (2) frontoventral-transverse cirral anlagen I–VI are segmented in the ordinary pattern 1:3:3:3:4:4 from left to right, which form three frontal, four frontoventral, one buccal, three postoral ventral, two pretransverse ventral and five transverse cirri, respectively; (3) dorsal morphogenesis is in the typical Oxytricha-pattern, but fragmentation of dorsal kinety 3 is indistinct; and (4) three caudal cirri are formed, one at the posterior end of each of dorsal kineties 1, 2 and 4. Phylogenetic analyses based on SSU rDNA sequences showed that M. euglenivorum euglenivorum clustered with Kleinstyla dorsicirrata and Heterourosomoida lanceolata rather than with its congener M. elegans. The genus Monomicrocaryon is not monophyletic in this study; however, its monophyly is not rejected by the AU test.     

Amphileptus aeschtae nov. spec. and Amphileptus eigneri nov. spec. (Ciliophora, Pleurostomatida), two new marine pleurostomatid ciliates from China

The morphology and infraciliature of two pleurostomatid ciliates, Amphileptus aeschtae nov. spec. and Amphileptus eigneri nov. spec., collected from shrimp-culturing ponds of the Bohai Sea, China, were investigated using live observations and the protargol impregnation method. The new species A. aeschtae is identified by the presence of 200-300 macronuclear nodules and several contractile vacuoles along the ventral side of the cell. A. eigneri differs from its congeners, inter alia, by the marine habitat, the presence of many contractile vacuoles along the ventral margin and the number of somatic kineties on both sides. Loxophyllum ozakii Shigematsu, 1953 is transferred to Kentrophyllum.     

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.     

Typification of the genus Dileptus Dujardin, 1841 (Ciliophora,Rhynchostomatia)

In their monograph of the dileptids, Vďačný and Foissner (2012) could not clarify the type species of the genus Dileptus Dujardin, 1841. Thus, they suggested that the problem be referred to the International Commission on Zoological Nomenclature. However, recently we discovered that Dujardin (1841) has originally typified Dileptus with Amphileptus anser sensu Ehrenberg (1838) which is in fact a misidentified Amphileptus margaritifer Ehrenberg, 1833, a common species also originally classified in Dileptus. Under Article 70.3.2 of the Code, Dileptus margaritifer (Ehrenberg, 1833) Dujardin, 1841, thoroughly redescribed by Foissner et al. (1995), is now the type of Dileptus. This has the great advantages of historical continuity and that new combinations (names) are not required.     

A redescription of the oxytrichid Tetmemena pustulata () and notes on morphogenesis in the marine urostylid Metaurostylopsis salina Lei et al., 2005 (Ciliophora,Hypotrichia)

Two hypotrichous ciliates from China were investigated. The common oxytrichid species Tetmemena pustulata (Müller, 1786) Eigner, 1999, isolated from the estuary of the Pearl River in southern China, was investigated with emphasis on its living morphology and infraciliature. Tetmemena pustulata is characterized as follows: body elliptical to obovoid in shape; 75–115 × 40–60 μm in vivo; two macronuclear nodules and two micronuclei; one contractile vacuole left of midline and somewhat ahead of midbody positioned; three frontal, four frontoventral, one buccal, three postoral ventral, two pretransverse ventral and five transverse cirri; cirrus III/2 ahead of level of cirrus IV/3; cirrus IV/2 arranged more anteriorly than cirrus V/4; transverse cirri not forming two distinct groups; three prolonged and widely separated caudal cirri; six dorsal kineties in Oxytricha-pattern with dorsal kineties 3 and 4 bipolar. The marine urostylid species Metaurostylopsis salina Li et al., 2005, isolated from an aquarium in Qingdao, northern China, was investigated with emphasis on its morphogenesis which is characterized by the de novo formation of the oral primordium in the proter and the development of the marginal rows from two anlagen that form within each parental structure separately in both dividers.     

The Morphology of Three Loxophyllum Species (Ciliophora,Pleurostomatida) from Southern China,L. lembum sp. n., L. vesiculosum sp. n. and L. perihoplophorum Buddenbrock, 1920, with Notes on the Molecular Phylogeny of Loxophyllum

Two new pleurostomatid ciliates, Loxophyllum lembum sp. n., L. vesiculosum sp. n., and the poorly known L. perihoplophorum Buddenbrock, 1920, isolated from brackish waters in coastal regions of southern China, are described following observations of live cells and protargol‐impregnated specimens. Loxophyllum lembum sp. n. is distinguished by a combination of characters including two macronuclear nodules, 6–9 contractile vacuoles along the ventral margin, 11–14 right and 6–8 left kineties and the presence of cortical granules. Loxophyllum vesiculosum sp. n. differs from its congeners mainly by the unique distribution of contractile vacuoles, several of which lie along the dorsal margin and one on the ventral margin, and 15–21 right and 6–8 left kineties. Loxophyllum perihoplophorum is characterized by its large cell size (350–450 μm long in vivo), 3–5 contractile vacuoles along the dorsal margin in the posterior region of the body, and 19–23 right and 7–9 left kineties. An improved diagnosis of L. perihoplophorum is provided. The SSU rDNA sequence of L. perihoplophorum is reported for the first time and its molecular phylogeny is analyzed. Maximum likelihood and Bayesian inference analyses of SSU rDNA sequence data recover the monophyly both of the order Pleurostomatida and of the genus Loxophyllum.     

Redescription of Parasonderia vestita () comb. nov. (Ciliophora,Plagiopylida), with notes on its phylogeny based on SSU rRNA gene

During faunistic studies on psammophilic ciliates along the coast of Qingdao, China, a population of the poorly known species Parasonderia vestita (Kahl, 1928) comb. nov. (basionym: Plagiopyla vestita Kahl, 1928) was found and investigated using silver staining methods. These revealed that its oral ciliature is rather unique and composed of polykinetids comprising four parts: prebuccal polykineties, postbuccal polykineties, parabuccal polykineties, and intrabuccal polykineties. Both the pre- and the postbuccal polykineties are, as extensions of the somatic kineties, spiraling and extending from cell surface into buccal cavity. The somatic kineties are composed mainly of dikinetids with some monokinetids and trikinetids inserted. They are separated into two types: four circle kineties and 24–28 bipolar kineties. The circle kineties start from the side of oral region and connect with the opposite section at the end of the body. Phylogenetic analysis based on SSU rRNA gene sequence data indicates that P. vestita falls into the core part of the order Plagiopylida and groups with an environmental sequence with high support and forms a sister clade with Lechriopyla mystax, Plagiopyla frontata and P. nasuta.     

Morphology and SSU rRNA gene sequences of three Frontonia species,including a description of F. subtropica spec. nov. (Ciliophora,Peniculida)

The morphology and infraciliature of three Frontonia species, F. subtropica spec. nov., F. canadensis Roque and Puytorac, 1972, and F. magna Fan et al., 2011, isolated from coastal waters in southern China sea, were investigated using living observation and silver impregnation methods. Frontonia subtropica spec. nov. is recognized by the combination of the following characters: body elliptical in outline with right margin depressed in anterior third, about 180–230 μm × 60–80 μm in vivo; 104–114 somatic kineties; peniculi 1–3 each with four kineties; five vestibular and five postoral kineties; one centrally located elongate-elliptical macronucleus; single contractile vacuole located left-dorsally in posterior third of body. We also provide improved diagnoses for F. canadensis and F. magna based on current and previous reports. The small subunit (SSU) rRNA gene was sequenced for all three species. Comparisons with sequences of morphologically similar congeners clearly support the validity each species.     

Morphology and Phylogeny of Three Trachelocercid Ciliates,with Description of a New Species,Trachelocerca orientalis spec. nov. (Ciliophora,Karyorelictea)

Three trachelocercid ciliates, Trachelocerca orientalis spec. nov., Prototrachelocerca fasciolata (Sauerbrey, 1928) Foissner, 1996 and Tracheloraphis huangi Xu et al., 2011, isolated from marine coastal habitats at Qingdao, China, were taxonomically studied using observation in vivo and silver staining methods. The new species T. orientalis spec. nov. can be recognized by the combination of its size (600–1,200 μm in vivo), 15–21 somatic kineties and about 13 groups of macronuclear nodules forming a strand and the colorless globular cortical granules. Together with the sequence data of the small subunit ribosomal RNA (SSU rRNA) gene, the information of a new isolate of P. fasciolata and three populations of T. huangi is also documented based on the present work. According to the molecular data, the phylogeny of three species is estimated and the analyses show that they are all found within the trachelocercid assemblage though T. huangi does not cluster with its congeners but with Trachelocerca species. Nonetheless, the monophyly of Trachelocerca is not rejected by the approximately unbiased test (p = 0.345 > 0.05), while that of Tracheloraphis is not confirmed (p = 0.0002 < 0.05).     

Description of a new marine cyrtophorid ciliate, Dysteria derouxi nov. spec., with an updated key to 12 well-investigated Dysteria species (Ciliophora, Cyrtophorida)

The morphology of living cells and the infraciliature of a new marine cyrtophorid ciliate, Dysteria derouxi nov. spec., collected from the coastal area of Qingdao, China, have been investigated. This species is characterized by: size about 100×40 μm in vivo, body rectangular in outline; 8 ventral kineties in the right field, of which the right-most 3 extend dorso-apically; 6–9 short kineties in the left equatorial field; two ventral contractile vacuoles; and marine habitat. Based on the data of morphology and infraciliature, an updated key to 12 Dysteria species is supplied.