Quantitative characteristics and features of formation of the structure of alien species in macrozoobenthos communities of the kuibyshev reservoir and its tributaries

The long-term dynamics of diversity and spread of alien species in the benthic communities of the Kuibyshev Reservoir are investigated. Contemporary list of invaders comprises 23 species. Dissemination of 4 species of crustaceans (Mysidae, Gammaridae): Katamysis warpachowskyi, Shablogammarus chablensis, Chaetogammarus warpachowsky, Stenogammarus compressus was established for the first time in 2009-2010. The features of the spatial distribution of alien species in shallow and deepwater parts of the Kuibyshev Reservoir are studied. The long-term structural changes in the benthic communities such as quantitative substitution of korofiid Chelicorophium curvispinum (Amphipoda, Crustacea) by polychaete Hypania invalida (Annelidae) are identified. It is shown that mollusks and crustaceans have the most invasive activity both in the reservoir and its tributaries. The assimilation of cenosis of crustaceans in the consortium of Dreissena bugensis was established. Mussels ensure the vital functions of the typical representatives of different trophic groups.