title: One freshwater species of the genus Cyclidium, Cyclidiumsinicum spec. nov. (Protozoa; Ciliophora), with an improved diagnosis of the genus Cyclidium.
abstract: The morphology and infraciliature of one freshwater ciliate, Cyclidium sinicum spec. nov., isolated from a farmland pond in Harbin, northeastern China, was investigated using living observation and silver staining methods. Cyclidium sinicum spec. nov. could be distinguished by the following features: body approximately 20-25×10-15 µm in vivo; buccal field about 45-50 % of body length; 11 somatic kineties; somatic kinety n terminating sub-caudally; two macronuclei and one micronucleus; M1 almost as long as M2; M2 triangle-shaped. The genus Cyclidium is re-defined as follows: body outline usually oval or elliptical, ventral side concave, dorsal side convex; single caudal cilium; contractile vacuole posterior terminal; adoral membranelles usually not separated; paroral membrane 'L'-shaped, with anterior end terminating at the level of anterior end of M1; somatic kineties longitudinally arranged and continuous. Phylogenetic trees based on the SSU rDNA sequences showed that C. sinicum spec. nov. clusters with the type species, Cyclidiumglaucoma, with full support. Cyclidium is not monophyletic with members of the clade of Cyclidium+Protocyclidium+Ancistrum+Boveria.
authors.affiliation: College of Life Science and Technology, Harbin Normal University, Harbin 150025, PR China.
authors.forename: Xuming
authors.initials: X
authors.lastname: Pan
authors.affiliation: College of Life Science and Technology, Harbin Normal University, Harbin 150025, PR China.
authors.forename: Chengdong
authors.initials: C
authors.lastname: Liang
authors.affiliation: Institute of Evolution & Marine Biodiversity, Ocean University of China, Qingdao 266003, PR China.
authors.forename: Chundi
authors.initials: C
authors.lastname: Wang
authors.affiliation: Department of Life Sciences, Natural History Museum, London SW7 5BD, UK.
authors.forename: Alan
authors.initials: A
authors.lastname: Warren
authors.affiliation: College of Life Science and Technology, Harbin Normal University, Harbin 150025, PR China.
authors.forename: Weijie
authors.initials: W
authors.lastname: Mu
authors.affiliation: College of Life Science and Technology, Harbin Normal University, Harbin 150025, PR China.
authors.forename: Hui
authors.initials: H
authors.lastname: Chen
authors.affiliation: College of Life Science and Technology, Harbin Normal University, Harbin 150025, PR China.
authors.forename: Lijie
authors.initials: L
authors.lastname: Yu
authors.affiliation: College of Life Science and Technology, Harbin Normal University, Harbin 150025, PR China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Chen
mesh_terms: D002681:China; D004275:DNA, Ribosomal / Q000235:genetics; D005618:Fresh Water / Q000382:microbiology*; D016802:Oligohymenophorea / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification; D010802:Phylogeny; D017422:Sequence Analysis, DNA
chemical_list: D004275:DNA, Ribosomal
keywords: Cyclidium; Cyclidium sinicum spec. nov.; SSU rDNA sequence; new species