title: Two new marine ciliates, Caryotricha rariseta n. sp. and Discocephalus pararotatorius n. sp. (Ciliophora, Spirotrichea), with phylogenetic analyses inferred from the small subunit rRNA gene sequences.
abstract: The morphology, infraciliature, and molecular phylogeny of two novel spirotrich ciliates, Caryotricha rariseta n. sp. and Discocephalus pararotatorius n. sp., isolated from coastal waters of China, were investigated. Caryotricha rariseta n. sp. differs from its congeners mainly in possessing seven sparsely ciliated cirral rows that are conspicuously shortened posteriorly and three transverse cirri aligned in a row. Discocephalus pararotatorius n. sp. is characterized by the conspicuous spine-like dorsal cilia, one extra (endoral?) membrane, and seven frontal, six ventral, and seven posterolateral marginal cirri. The small subunit rRNA gene was sequenced for both species. Complete SSU rRNA gene sequences of two Caryotricha spp. (including C. rariseta n. sp.) and two Discocephalus spp. (including D. pararotatorius n. sp.), along with those of 40 other ciliates, were used to determine their molecular phylogeny using maximum likelihood, neighbor joining and maximum parsimony analyses. The two Caryotricha species cluster with Kiitricha marina in the well-supported Protohypotrichia clade that is basal to the main spirotrich assemblage. The two discocephalids form a clade that is sister to the Hypotrichia.
authors.affiliation: College of Life Sciences, University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, China.
authors.forename: Jiamei
authors.initials: J
authors.lastname: Jiang
authors.forename: Yi
authors.initials: Y
authors.lastname: Xing
authors.forename: Miao
authors.initials: M
authors.lastname: Miao
authors.forename: Chen
authors.initials: C
authors.lastname: Shao
authors.forename: Alan
authors.initials: A
authors.lastname: Warren
authors.forename: Weibo
authors.initials: W
authors.lastname: Song
mesh_terms: D016798:Ciliophora / Q000145:classification / Q000235:genetics*; D020459:Genes, rRNA / Q000235:genetics*; D010802:Phylogeny
keywords: Ciliata; SSU rDNA; morphology; new species; phylogeny; taxonomy