Helminths of Fedorov's lumpsucker Eumicrotremus fedorovi Mandrytsa, 1991 (Actinopterygii: Cyclopteridae) in the Simushir Island area (Pacific Ocean).

Fedorov's lumpsucker, Eumicrotremus fedorovi Mandrytsa, 1991, is native to the Kuril Islands area. Two sets of 69 and 30 adult specimens of E. fedorovi caught on the continental shelf and slope of Simushir Island in the Pacific Ocean were dissected and studied for macroparasites. The studied specimens were heavily infected with plerocercoids of Nybelinia surmenicola and Ascarophis pacifica. For the first time, 15 parasite taxa were recorded for E. fedorovi. None of the parasites found are solely specific to the E. fedorovi or to the representatives of the family Cyclopteridae. The infection of E. fedorovi could be dramatically different in different parts of the Simushir Island area in terms of parasite species composition and intensity of infection.