Distribution of Alien Species of Macrozoobenthos and the Species Cenotic Complexes in the Kama Reservoirs

The results of studies on the distribution of alien species in macrozoobenthic communities in the reservoirs of the Kama River cascade are presented. In total, 25 alien species of Ponto-Caspian and Ponto-Azov origins and one species—a representative of the Lake Baikal fauna—were registered. Differences in the species composition and structural characteristics of macrozoobenthos invaders in the Kama and Volga reservoirs were revealed. It was noted that mollusks of genus Dreissena dominate in biomass in most of the studied biotopes. Three types of cenotic complexes of alien species were identified: psammopelophilic profundal, characteristic of the Nizhnekamsk Reservoir and the Volgo-Kamsky and Kamsky reaches of the Kuybyshev Reservoir; the psammopelophilic coastal in the Nizhnekamsk Reservoir; and the psammopelophilic coastal in Votkinsk and Kama reservoirs.