Tracheliastes sachalinensis (Copepoda: Lernaeopodidae), a fin parasite of leuciscids, new to Honshu, the main island of Japan

Abstract

Females of the lernaeopodid copepod Tracheliastes sachalinensis Markevich, 1936 were collected from the fins of big-scaled redfin, Pseudaspius hakonensis (Günther, 1877) (Cypriniformes: Leuciscidae) in a stream at the Nagano Prefectural Fisheries Experimental Station, Azumino, Nagano Prefecture, central Japan. In this country, the copepod was previously reported only from Hokkaido, and the present collection represents the first record of T. sachalinensis from Honshu, the main island of Japan. The females of the species are briefly described. Prevalence was 24.0% in 50 fish examined and the number of copepods per infected host ranged from 1–3 (mean intensity, 1.3). The anal fin was most frequently infected.