Taxonomy of trichodinids from the gills of marine fishes in coastal regions of the Yellow Sea, with descriptions of two new species of Trichodina Ehrenberg, 1830 (Protozoa: Ciliophora: Peritrichia).

Seven species of marine fishes from coastal regions of the Yellow Sea were examined for ectoparasitic trichodinids (Protozoa, Ciliophora). A total of seven species belonging to the genus Trichodina Ehrenberg, 1830, including two new species, occurred as gill parasites. These were T. rectispina n. sp., T. circinantis n. sp., T. frequentis Shtein, 1979, T. jarmilae Lom & Laird, 1969, T. hexagrammi Zhukov, 1964, T. minima Shtein, 1979 and T. ovonucleata Raabe, 1958. Each was investigated following silver nitrate and protargol impregnation. Morphometric data and comparative descriptions of these trichodinids are provided along with details of their prevalence and intensity of infestation.