title: Morphological and Molecular Identification of the New Species, Trichodina pseudoheterodentata sp. n. (Ciliophora, Mobilida, Trichodinidae) from the Channel Catfish, Ictalurus punctatus, in Chongqing China.
abstract: It is difficult to differentiate similar trichodinids solely based on morphological examination, thus other identification methods, such as molecular identification, are necessary for identification. One mobilid ciliate named Trichodina pseudoheterodentata sp. n. was isolated from the gills of channel catfish, Ictalurus punctatus, in Chongqing, China. In the present study, its SSU rDNA was sequenced for the first time. Based on the results from both morphological identification and SSU rDNA sequencing, the new species was identified and compared with similar species. The morphological analysis revealed that T. pseudoheterodentata is a large Trichodina species (cell diameter 73.0-82.5 μm) and possesses robust denticles with broad blades and well-developed blade connections. Characterization of its primary and secondary SSU rDNA structures indicated that T. pseudoheterodentata was distinctly different from congeneric species in H12, H15, E10_1, and V4 regions. Phylogenetic analysis revealed that the genetic distances among the new species and similar species reached interspecific levels, furthermore, the phylogenetic study also validated the identification of T. pseudoheterodentata and its placement in the genus Trichodina.
authors.affiliation: Chongqing Key Laboratory of Animal Biology, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Fahui
authors.initials: F
authors.lastname: Tang
authors.affiliation: Chongqing Key Laboratory of Animal Biology, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Chongqing Key Laboratory of Animal Biology, Chongqing Normal University, Chongqing, 401331, China.
authors.forename: Yuanjun
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001483:Base Sequence; D002681:China; D016770:Ciliophora Infections / Q000469:parasitology / Q000662:veterinary*; D016054:DNA, Protozoan / Q000235:genetics; D004275:DNA, Ribosomal / Q000235:genetics; D005393:Fish Diseases / Q000469:parasitology*; D005880:Gills / Q000469:parasitology; D007059:Ictaluridae / Q000469:parasitology*; D016802:Oligohymenophorea / Q000145:classification* / Q000166:cytology / Q000235:genetics / Q000302:isolation & purification; D010802:Phylogeny
chemical_list: D016054:DNA, Protozoan; D004275:DNA, Ribosomal
keywords: Freshwater trichodinid; Phylogeny; SSU rDNA