Fish parasites from the Gizhiga River basin (northern coast of the Okhotsk Sea)
The first parasitological investigation of fish from the Gizhiga River basin. The Gizhiga is salmon river flowing into the northern Okhotsk Sea. In total, 48 species of parasites (including 3 copepods and 45 helminthes) are found which belong to 37 genera of 27 families of 15 orders of 6 classes of 4 types. A half of them (24 species) are freshwater species and others are marine ones. Anadromous chars and pacific salmons have the most diverse fauna of parasites (30 and 21 species, respectively), and arctic grayling, northern pike and thin-tailed burbot are infected by 17, 14, and 8 species only. Marine copepod Lepeophtheirus salmonis is typical parasite for all anadromous salmonids, but dolly warden has freshwater copepod Salmincola carpionis, and arctic grayling - Salmincola sp., as well. Possible ways of freshwater fish species infestation by marine parasites are discussed. Nematode Anisakis simplex is the only parasitic species dangerous from medical-veterinary point of view.