qiong Li

Morphology, ontogeny, and molecular phylogeny of two novel bakuellid-like hypotrichs (Ciliophora: Hypotrichia), with establishment of two new genera

The morphology, ontogeny and molecular phylogeny of Apobakuella fusca gen. n., sp. n. and Parabistichella variabilis gen. n., sp. n., from south China were investigated. Apobakuella fusca, brown colored, demonstrates bakuellid-like infraciliature, and a similar ontogenesis as the genus Bakuella. It is argued, however, that this species represents a novel genus, Apobakuella, which is characterized by two or more marginal rows on the right, several buccal and parabuccal cirri, and lack of frontoterminal and caudal cirri. Phylogenetic analysis based on SSU rRNA gene sequences supports the close relationship of Apobakuella with Neobakuella and Diaxonella within the core Urostylida. By contrast, Parabistichella variabilis has a dominant frontoventral row, few midventral pairs, a long midventral row, and one marginal row on each side. Its morphogenesis exhibits: (1) partial reorganization of the parental adoral membranelles; (2) over six frontoventral-transverse cirri anlagen; (3) intrakinetal development of the midventral row; and (4) very likely, formation of the frontoventral row from the midventral row anlage. Both the morphological characteristics and the SSU rRNA gene sequences suggest that it is incertae sedis among the basal hypotrichs. Further investigation of key taxa with additional molecular markers is required to reveal a better understanding on the phylogeny of Parabistichella.

Re-Evaluation on the Diversity of the Polyphyletic Genus Metaurostylopsis (Ciliophora, Hypotricha): Ontogenetic, Morphologic, and Molecular Data Suggest the Establishment of a New Genus Apourostylopsis n. g.

ABSTRACT. The urostylid genus Metaurostylopsis Song et al., 2001 was considered to be a well‐outlined taxon. Nevertheless, recent evidence, including morphological, ontogenetic, and molecular information, have consistently revealed conflicts among congeners, regarding their systematic relationships, ciliature patterns, and origins of ciliary organelles. In the present work, the morphogenetic and morphogenetic features were re‐checked and compared, and the phylogeny of nominal species was analysed based on information inferred from the small subunit ribosomal RNA (SS rRNA) gene sequence. In addition, the binary divisional process in a new isolate of Metaurostylopsis struederkypkeae Shao et al., 2008 is described. All results obtained reveal that the genus is a polyphyletic assemblage whose nominal congeners fall into three clades within the core Urostylida, based on SS rRNA gene sequences. These three clades not match the groups inferred from morphological/morphogenetical evidences. Some conflicting data from molecular and ontogenetic studies also indicate that single‐gene information might not be consistently reliable in detecting the phylogenetic relationships among closely related groups and comprehensive multi‐gene analyses are necessary to give a more exact evaluation for this divergent assemblage. According to our new understandings, five forms are confirmed to be true Metaurostylopsis. The morphotype Metaurostylopsis sinica Shao et al., 2008 should be excluded from the genus and represents a distinct type, and, thus, a new genus Apourostylopsis n. g. with it as the type specie, i.e. Apourostylopsis sinica (Shao et al., 2008) n. comb.

The morphology, morphogenesis and SSrRNA gene sequence of a new marine ciliate, Diophrys apoligothrix spec. nov. (Ciliophora; Euplotida).

The morphology, morphogenesis and small subunit rRNA (SSrRNA) gene sequence of a new marine euplotid ciliate, Diophrys apoligothrix spec. nov., isolated from a sandy beach near Qingdao, north China, were investigated. This organism is characterized as follows: rigid body with a sculptured surface; size in vivo about 60-110 x 40-70microm; adoral zone comprising about 28 membranelles; five frontal, two ventral, five transverse, one left marginal and three caudal cirri; five dorsal kineties with sparsely distributed dikinetids; two ellipsoid macronuclear nodules; marine habitat. Although the main morphogenetic events are similar to those reported in other congeners, three features are noteworthy: (1) the parental adoral zone is retained almost unchanged by the proter except for the outer margin of membranelles in the proximal portion, where the de-differentiation and then reorganization take place in situ in the mid-to-late phases of division; (2) the dorsal kinety anlagen are formed via a two-step mode; (3) the marginal cirrus anlage is formed de novo near the old structure and does not divide. Based on the morphological, morphogenetic and SSrRNA gene sequence data, it was concluded that D. apoligothrix is a well-outlined and distinctive member of the genus Diophrys.

A redescription of the marine hypotrichous ciliate, Nothoholosticha fasciola (Kahl, 1932) nov. gen., nov. comb. (Ciliophora: Urostylida) with brief notes on its cellular reorganization and SS rRNA gene sequence

The morphology and infraciliature of the marine hypotrichous ciliate Nothoholosticha fasciola (Kahl, 1932) nov. gen., nov. comb., isolated from mariculture waters near Qingdao, China, are redescribed based on live and protargol-impregnated specimens. Features reported for the first time include the possession of more than 50 macronuclear nodules and details of the infraciliature, i.e. 50-60 adoral membranelles, shortened paroral and endoral membranes, six frontal, one buccal and two to seven transverse cirri, ca. 40 pairs of midventral cirri, ca. 60-120 left and 70-120 right marginal cirri, three dorsal kineties, caudal and frontoterminal cirri absent. In addition, brief details of two stages of cellular reorganization in N. fasciola are supplied and comparisons with some related urostylids based on SS rRNA gene sequence data are reported. The new genus Nothoholosticha is established based primarily on the absence of frontoterminal cirri, which distinctly separates it from similar urostylid genera. Anteholosticha longissima is transferred to Nothoholosticha as N. longissima (Dragesco and Dragesco-Kernéis, 1986) nov. comb. and Holosticha antarctica is transferred to Pseudokeronopsis as P. antarctica (Wilbert and Song, 2008) nov. comb.

Redescriptions of Two Marine Hypotrichous Ciliates, Diophrys irmgard and D. hystrix (Ciliophora, Euplotida), with a Brief Revision of the Genus Diophrys

ABSTRACT. Two insufficiently described marine euplotids, Diophrys irmgard Mansfeld (1923) and Diophrys hystrix Buddenbrock (1920) , found in coastal waters near Qingdao, China, were reinvestigated with emphasis on their living morphology and infraciliature. Improved diagnoses and redescriptions are supplied for both organisms. Critical redefinitions of nine morphotypes are presented and the validities of the nominal species are discussed and briefly revised. Following Curds and Wu (1983) , and based on data obtained during the present study and a critical review of the literature, five additional nominal species are regarded as junior synonyms of known forms: Diophrys quadricaudatus Agamaliev (1967) , D. scutoides Agamaliev (1967) , and D. tetramacronucleata Kattar (1970) are synonymized with D. scutum ( Dujardin 1841 ), while D. pentacirratus Alekperov (1984) and D. multicirratus Alekperov (1984) are junior synonyms of D. oligothrix Borror (1965) .

Molecular phylogeny of the scuticociliate, Philaster (Protozoa, Ciliophora), with a description of a new species, P. apodigitiformis sp. nov.

Abstract The systematic position of the scuticociliate, Philaster, has been highly ambiguous owing to a lack of either morphogenetic or molecular information. The small subunit rRNA gene of a new species, Philaster apodigitiformis sp. nov. was isolated from eggs of the puffer fish (Takifugu rubripes), was sequenced, and phylo‐genetic trees were constructed with different methods to assess its position and relationship among the scuticociliates. Results indicate that (1) Philaster apodigitiformis clearly falls into the order Philasterida and it is most closely related to the Uronema‐Paranophrys assemblage, which groups with clusters consisting of families Uronematidae, Parauronematidae, Thyrophilacidae and Entorhipidiidae; (2) the two genera Philaster and Philasterides presently assigned to the family Philaster‐idae are in widely separated clades, indicating that the family is polyphyletic; and (3) the morphological similarity of Philaster and Philasterides is probably an example of evolutionary convergence. The new species P. apodigitiformis is recognised by a combination of the following features: body oval and slightly bilaterally flattened, cilia of paroral membrane conspicuously long and forming a sail‐like shape, both membranelle 1 and 2 dominant, and approximately 40 somatic kineties present.

Morphology and morphogenesis of a new marine ciliate, Apokeronopsis bergeri nov. spec. (Ciliophora, Hypotrichida), from the Yellow Sea, China

The morphology and morphogenesis of a new marine hypotrich ciliate, Apokeronopsis bergeri nov. spec., collected from mussel-farming waters near Qingdao, China, are described from living and protargol-impregnated specimens. This ciliate has characteristics that place it in the family Pseudokeronopsidae, namely, two long rows of frontal cirri (bicorona), which are continuous with the long midventral rows, and a single row of marginal cirri on each side of the body. It shares with its only congener, Apokeronopsis crassa, the long rows of buccal and transverse cirri and the wide spacing between the midventral rows of cirri. These characters separate the genus Apokeronopsis from Pseudokeronopsis, which has a single buccal cirrus, fewer transverse cirri and midventral rows of cirri arranged in a typical zig-zag pattern. A. bergeri differs from A. crassa in its shape, colour and in the numbers of membranelles and transverse cirri. Although morphogenesis in A. bergeri is similar to that of A. crassa in most respects, the mode of formation of the buccal cirri is slightly different. The close relationship of A. bergeri with A. crassa, and the more distant relationship with three Pseudokeronopsis species, is supported by a comparison of the sequences of their ITS1-5.8S-ITS2 rDNA regions.

Caryotricha minuta (Xu et al., 2008) nov. comb., a unique marine ciliate (Protista, Ciliophora, Spirotrichea), with phylogenetic analysis of the ambiguous genus Caryotricha inferred from the small-subunit rRNA gene sequence.

A population of Kiitricha minuta Xu et al., 2008, a small kiitrichid ciliate, was isolated from a brackish water sample in Jiaozhou Bay, Qingdao, northern China. After comparison of its morphology and infraciliature, it is believed that this morphotype should be assigned to the genus Caryotricha; hence, a new combination is suggested, Caryotricha minuta (Xu et al., 2008) nov. comb. The small-subunit (SSU) rRNA gene sequence was determined in order to elucidate the phylogenetic position of this poorly known, ambiguous genus. The organism can be clearly separated from its congener, Caryotricha convexa Kahl, 1932, by the extremely shortened ventral cirral rows in the posterior ends. Based on the data available, an improved diagnosis is given for the genus: marine Kiitrichidae with prominent buccal field; two highly developed undulating membranes; non-grouped, uniform cirral rows on both ventral and dorsal sides; enlarged transverse cirri present, which are the only differentiated cirri; marginal cirri not present; one short migratory row located posterior to buccal field; structure of dorsal kineties generally in Kiitricha pattern. The sequence of the SSU rRNA gene of C. minuta differs by 13 % from that of Kiitricha marina. Molecular phylogenetic analyses (Bayesian inference, least squares, neighbour joining, maximum parsimony) indicate that Caryotricha, together with Kiitricha, diverges at a deep level from all other spirotrichs. Its branching position is between Phacodiniidia and Licnophoridia. The results strongly support the distinct separation of the Kiitricha-Caryotricha clade, which always branches basal to the Stichotrichia-Hypotrichia-Oligotrichia-Choreotrichia assemblage. These results also confirm the previous hypothesis that the Kiitricha-Caryotricha group, long assumed to be a close relation to the euplotids, represents a taxon at subclass level within the spirotrichs.

Morphology and ontogenesis of a marine ciliate, Euplotes balteatus (Dujardin, 1841) Kahl, 1932 (Ciliophora, Euplotida) and definition of Euplotes wilberti nov spec.

1School of Ocean, Yantai Academe, China Agricultural University, China; 2Laboratory of Protozoology, Institute of Evolution and Marine Biodiversity, Ocean University of China, Qingdao, China; 3Department of Biology and Engineering, School of Life Science and Technology, Xi’an Jiaotong University, Xi’an, China; 4Zoology Department, College of Science, King Saud University, Riyadh, Saudi Arabia; 5Department of Zoology, Natural History Museum, London, UK

Redescription of a Poorly Known Marine Ciliate, Leptoamphisiella vermis Gruber, 1888 n. g., n. comb. (Ciliophora, Stichotrichia, Pseudoamphisiellidae), from the Yellow Sea, China

ABSTRACT. Leptoamphisiella vermis Gruber, 1888 n. g., n. comb. (basionym Epiclintes vermis Gruber, 1888 ) is an extraordinarily large and worm‐like marine stichotrichous ciliate. Based on a population isolated recently from coastal waters of Qingdao, China, the living morphology and infraciliature are redescribed and its taxonomic position is defined. Accordingly, a new diagnosis for this species is suggested: large, marine Leptoamphisiella with a conspicuous layer of pellicular alveoli; 400–1000 μm × 40–70 μm in vivo; body band‐like, highly flexible; about 40 membranelles; always three frontal and two buccal cirri; 52–80 transverse cirri (TC) extending to the posterior end of the buccal field; 57–79 left midventral and 44–62 right midventral cirri; 62–102 cirri in left and 63–91 cirri in right marginal rows (MR); 9–13 dorsal kineties that extend the full body length; about 100 macronuclear nodules and 5–13 micronuclei. The diagnosis for the new genus is as follows: vermiform Pseudoamphisiellidae with strongly contractile body, differentiated frontal, buccal, and highly developed TC; two remarkably separated midventral rows; one MR on each side of the body; frontoterminal and caudal cirri absent. Leptoamphisiella vermis n. comb. is fixed as the type species of the new genus.