title: Phylogenetic positions of four hypotrichous ciliates (Protista, Ciliophora) based on SSU rRNA gene, with notes on their morphological characters.
abstract: The morphology and infraciliature of the four hypotrichous ciliates; Rigidohymena inquieta (Stokes, 1887) Berger, 2011, Pattersoniella vitiphila Foissner, 1987, Notohymena australis Foissner & O' Donoghue, 1990, and Cyrtohymena (Cyrtohymenides) australis (Foissner, 1995) Foissner, 2004, collected from east China, were investigated by using live observation and protargol impregnation method. An improved diagnosis for R. inquieta was supplied based on descriptions of present and previous populations. New morphology and morphogenesis information based on Chinese populations of another three hypotrichids were also supplemented. The Small-subunit rRNA (SSU rRNA) gene sequences of the four species were characterized and their phylogenetic positions were revealed by means of Bayesian inference and Maximum-likelihood analysis. The analyses shows that R. inquieta clusters with other members of the subfamily Stylonychinae, which confirms the monophyly of the subfamily and verified R. inquieta as a separated species from R. candens though it differs from others mainly by body size. C. (C.) australis occupying the basal position of the clade which contains cyrtohymenids and some other groups, declines the idea of separating Cyrtohymena into two subgenus. Notohymena australis and China population of Pattersoniella vitiphila respectively clustering with their congeners correspond well with the systematics revealed by morphological similarities.
authors.affiliation: School of Life Sciences, East China Normal University, Shanghai 200062, China;; Email: unknown.
authors.forename: Caiting
authors.initials: C
authors.lastname: Yang
authors.affiliation: School of Life Sciences, East China Normal University, Shanghai 200062, China;; Email: unknown.
authors.forename: An
authors.initials: A
authors.lastname: Liu
authors.affiliation: Laboratory of Protozoology, Key Laboratory of Ecology and Environmental Science in Guangdong Higher Education, South China Normal University, Guangzhou 510631, China;; Email: unknown.
authors.forename: Yusen
authors.initials: Y
authors.lastname: Xu
authors.affiliation: State Key Laboratory of Estuarine and Coastal Research, East China Normal University, Shanghai 200062, China;; Email: unknown.
authors.forename: Yuan
authors.initials: Y
authors.lastname: Xu
authors.affiliation: School of Life Sciences, East China Normal University, Shanghai 200062, China;; Email: unknown.
authors.forename: Xinpeng
authors.initials: X
authors.lastname: Fan
authors.affiliation: Zoology Department, College of Science, King Saud University, Riyadh 11451, Saudi Arabia; Email: unknown.
authors.forename: Saleh A
authors.initials: SA
authors.lastname: Al-Farraj
authors.affiliation: School of Life Sciences, East China Normal University, Shanghai 200062, China;; Email: unknown.
authors.forename: Bing
authors.initials: B
authors.lastname: Ni
authors.affiliation: School of Life Sciences, East China Normal University, Shanghai 200062, China;; Email: unknown.
authors.forename: Fukang
authors.initials: F
authors.lastname: Gu
mesh_terms: D049628:Body Size; D002681:China; D016798:Ciliophora / Q000145:classification* / Q000235:genetics / Q000254:growth & development; D016054:DNA, Protozoan / Q000235:genetics*; D004275:DNA, Ribosomal / Q000235:genetics*; D008969:Molecular Sequence Data; D009929:Organ Size; D010802:Phylogeny
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal