Fauna of <i>Coregonus sardinella</i> Parasites of the Indigirka River

The purpose of the research is studying fauna of Coregonus sardinella parasites of the Indigirka River.Materials and methods. The studies were carried out in August–September 2015–2017 in the lower reaches of the Indigirka River. A total of 421 specimens of C. sardinella were studied using partial parasitological autopsy method, of which: 227 specimens aged from 2+ to 12+ in 2015, 31 specimens aged from 4+ to 8+ in 2016, 163 specimens aged 2+ to 12+ in 2017. We used the determinant of parasites of fresh-water fish of the USSR fauna to determine the species affiliation of the revealed parasites. The infection intensity, and abundance index were assessed.Results and discussion. 12 species of parasites were found in C. sardinella of the Indigirka River, namely, 1 species of protozoa, 4 species of cestodes, 3 – nematodes, 1 species of scrubs, 1 species of leeches, 2 species of parasitic crustaceans. Among the parasitic diseases of C. sardinella that are dangerous to human health, diphyllobothriosis is registered, and trienophorosis is among those that affects the marketable appearance of fish. High infection of C. sardinella with Diphyllobotrium sp. in the water area of the Indigirka River has been observed for several decades, which suggests its leading role in the circulation of this helminth in the studied reservoir. The study of the fauna of C. sardinella parasites show the need for continuous monitoring of fish infection rates to prevent possible epizootics and even death of juvenile fish