Abstract / Introduction / Summary:
Sixteen metamorphosed females of a mesoparasitic copepod Lernaeenicus ramosus Kirtisinghe, 1956 were collected from a Hong Kong grouper, Epinephelus akaara (Temminck and Schlegel, 1842), at 50 m deep in Toyama Bay, an inlet of the Sea of Japan, off Hime, Noto, Ishikawa Prefecture, central Japan. The copepod is briefly described. In the Sea of Japan off the Japanese archipelago, L. ramosus has been reported only from western Japan, where the species was collected off Nagasaki, Yamaguchi, and Shimane prefectures. Toyama Bay represents a new locality record for the species, and the present collection extends its distributional range from off Shimane Prefecture northward to Toyama Bay in the Sea of Japan. There is information from fishermen engaged in grouper fishing in Toyama Bay that Hong Kong grouper with pennellid infection were caught for the first time in 2020 and heavily infected fish were frequently taken in 2021 and 2022.
