Ciliate ectoparasites (Ciliophora: Trichodinidae/Chilodonellidae) on gills of Carassius auratus from the Yangtze River, China, with the description of Trichodina luzhoues sp. n.

Three species of the genus Trichodina Ehrenberg, 1838 and one species of the genus Chilodonella Strand, 1926 were collected from gills of Carassius auratus. They are Trichodina luzhoues sp. n., Trichodina mutabilis Kazubski and Migala, 1968, Trichodina reticulata Hirschman and Partsch, 1955, and Chilodonella hexasticha Kiernik, 1909. T. luzhoues sp. n. is a medium-sized trichodinid, and its denticles are very distinctive: the blade is narrow rhombus shaped, the section connecting the blade and central part is long and very thin; the section connecting the central part and ray is short and very thick. Ch. hexasticha is a new record in China.