BENTHOFAUNA AND ICHTHYOFAUNA OF THE RIFFLE OF THE MEDIUM LOWLAND RIVER INHABITED BY <i>ALBBURNOIDES ROSSICUS </i>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.