Status of Isolated Coregonus peled Peled Populations from Mountain Lakes of Altai According to Histological Indices and Elemental Composition of Eye Lens

The state of the population of native fish species in three lakes of the Altai Mountains has been considered. The analysis of fish age and weight show that the populations of Coregonus peled Gmelin, 1788 peled demonstrate different growth dynamics in the studied reservoirs under conditions of oligotrophic mountain lakes. The age composition of fish differs in the reservoirs: for example, individuals of four age groups (from 1+ to 4+) are present in Lake Kedelu-Kol, while only yearlings are found in Lake Kidelu. A histological study of the liver and gills of fish detected the absence of significant abnormalities of parasitic and toxicological nature. The calculation of the histopathological index has demonstrated that the prevalence and severity of pathological abnormalities are significantly lower (p < 0.05) in Lake Kidelu. The study of the elemental composition of peled lens confirms the absence of a significant level of pollution of the studied reservoirs and the high quality of the aquatic environment. The presence of trace amounts of heavy metals in individual samples can be associated with the geomorphological peculiarities of the region that are involved in the formation of the hydrochemical composition of water of the studied lakes. The data obtained in the study indicate that the peled populations in isolated mountain lakes of Altai demonstrate a different degree of oppression in a number of traits.