Benthofauna and ichthyofauna of the riffle of the medium lowland river inhabited by Albburnoides rossicus Berg

The species composition of fish of the riffle of the Vala River was studied, in which a Russian spirlin was present. It occupies a leading position in the ichthyofauna for biomass and dominates in abundance, exceeding all other components. In benthic community we had found 46 taxa of 4 classes: Oligochaeta (4 species), Bivalvia (5), Gastropoda (1), Insecta (36). The largest share in zoobenthos biomass during the study period belonged to bivalved mollusks (48.2%), oligochaetes (21.7%) and caddis flies (8.4%); chi-ronomids (54.4%) and caddis flies (11.6%) predominated in abundance. The food spectrum of Russian spirlin Alburnoides rossicus from Vala River in the Udmurt Republic was studied. It consists of 33 components, among them 9% are algae and higher plants, 88%> - invertebrates, 3%> - mineral components. One types of insects were found: benthic forms, and land-air ones. According to food spectrum Russian spirlin may be considered as a typical polyphage.