The helminthofauna of the pink salmon Oncorhynchus gorbuscha (Walbaum, 1792) of south-east Sakhalin according to the results of many years of research

Abstract

The purpose of the research is to describe and analyze the qualitative and quantitative composition of pink salmon helminths of southeastern Sakhalin.Materials and methods. Standard parasitological methods of collecting material were used. At the autopsy, the ureters, eyeballs, gill petals and arches, and the brain of fish were not examined. The method of collecting salmon parasites in the laboratory has been unchanged since 1992. Collections of representatives of monogenetic suckers were not carried out. Parasitological studies of pink salmon of southeastern Sakhalin were carried out from 1992 to 2022, a total of 4163 fish specimens were examined. The fish is caught in the estuaries of rivers and the sea coast.Results and discussion. According to the results of their own research and literature data, the pink salmon helminth fauna of southeastern Sakhalin is represented by 23 species: Dibothriocephalus nihonkaiensis pl., Eubothrium salvelini, Eu. crassum, Nybelinia surmenicola pl., Pelichnibothrium speciosum pl., Tetraphyllidea gen. sp., Brachyphallus crenatus, Cryptocotyle sp. mtc., Hemiurus levinseni, Lecithaster gibbosus, Prosorhynchoides gracilescens, Parahemiurus merus, Derogenes varicus, Capiatestes thyrsitae, Corynosoma strumosum l., Echinorhynchus gadi, Bolbosoma caenoforme juv., B. bobrovoi juv., Rhadinorhynchus trachuri, Anisakis simplex l., Ascarophis pacifica, Ascarophis skrjabini, Hysterothylacium aduncum. The qualitative composition of the helminth fauna is currently undergoing minor changes, while the quantitative characteristics of some helminths are significantly reduced. Thus, the infection of pink salmon with Bolbosoma sp. juv scrapers. decreased to 0.61±0.18.