Abstract / Introduction / Summary:
The lernaeid copepod Lernaea cyprinacea Linnaeus, 1758 was found to parasitize three species of fishes in Lake Tôro and Lake Shirarutoro, eastern Hokkaido, northern Japan in August and September 1981. The parasitized fishes were the big scaled redfin, Tribolodon hakonensis (Günther, 1877), from Lake Tôro, the lake minnow, Rhynchocypris percnurus (Pallas, 1814), and the rainbow trout, Oncorhynchus mykiss (Walbaum, 1792), from Lake Shirarutoro, The copepod was collected from the lake minnow for the first time in Japan.
