title: Phylogenetic position of the genus Cyrtostrombidium, with a description of Cyrtostrombidium paralongisomum nov. spec. and a redescription of Cyrtostrombidium longisomum Lynn & Gilron, 1993 (Protozoa, Ciliophora) based on live observation, protargol impregnation, and 18S rDNA sequences.
abstract: We redescribe Cyrtostrombidium longisomum Lynn & Gilron, 1993, the type species of the genus Cyrtostrombidium, and describe the new species Cyrtostrombidium paralongisomum n. sp. using live observation, protargol staining and molecular data. The morphological characters of these two species are clearly distinct, i.e., dikinetid numbers in the girdle and ventral kineties; however, it is difficult to separate them by 18S rDNA sequences because they differ by only 8 bp, indicating that 18S rDNA sequences are insufficient for separating different species in the genus Cyrtostrombidium. We not only observed the position of the oral primordium in the genus Cyrtostrombidium but also observed a possibly homoplasious trait, a dorsal split in the girdle kinety, in (1) Apostrombidium, (2) Varistrombidium, and (3) Cyrtostrombidium/Williophrya. This partially supports the hypothesis of somatic ciliary pattern evolution recently put forth by Agatha and Strüder-Kypke.
authors.affiliation: Department of Marine Sciences, University of Connecticut, Groton, Connecticut, USA; Institute of Marine Environmental Chemistry and Ecology, National Taiwan Ocean University, Keelung, 202-24, Taiwan.
authors.forename: Sheng-Fang
authors.initials: SF
authors.lastname: Tsai
authors.forename: Wei-Ting
authors.initials: WT
authors.lastname: Chen
authors.forename: Kuo-Ping
authors.initials: KP
authors.lastname: Chiang
mesh_terms: D001483:Base Sequence; D016798:Ciliophora / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000648:ultrastructure; D004275:DNA, Ribosomal / Q000235:genetics; D020459:Genes, rRNA; D010802:Phylogeny; D012337:RNA, Ribosomal, 18S / Q000235:genetics; D012623:Seawater; D017422:Sequence Analysis, DNA; D012836:Silver Proteins
chemical_list: D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S; D012836:Silver Proteins; C003232:strong silver protein
keywords: Ciliary pattern; Cyrtostrombidiidae; homoplasious; morphology; taxonomy