Abstract

This study surveyed freshwater fishes Cyprinus carpio and Carassius auratus from Chongqing, China, for infection with ectoparasitic trichodinids. Fish specimens were obtained from culture pools, smears of gills were prepared and used for silver nitrate impregnation. Microbiologic studies identified two species of trichodinids belonging toTrichodina Ehrenberg, 1838 including one new species from C. carpio that was namedTrichodina cyprinocola sp. nov. Comparisons with closely related species revealed that this new species T. cyprinocola has unique sturdy denticles including the sickle blade with bluntly round tangent point, well developed central part, robust, straight but short ray. The other known species Trichodina borokensis Arthur and Lom (1984) from C. auratus was described here as the first record in China. Our survey also yielded morphometric data and prevalence of infestation for these two species. 

Key words: Trichodina, new species, freshwater fish, Cyprinus carpio, Carassius auratus.