Zoobenthos of the Littoral of the Sheksninsky Reservoir 25 Years after the Introduction of Gmelinoides fasciatus (Crustacea, Amphipoda)

In 2010–2020, studies of zoobenthos were carried out at 17 stations of the littoral zone of the Sheksninsky reservoir. A total of 138 species of zoobenthos have been observed. In the river part, the species richness and diversity of zoobenthos was higher than in the lake part. The invasive sidewinder Gmelinoides fasciatus (Stebbing, 1899), first recorded in 1995, caused changes in the zoobenthos of the reservoir. There has been an increase in the biomass of littoral zoobenthos. Some species of oligochaetes and chironomids have been displaced from the dominant species. Currently, the share of G. fasciatus accounts ≤50% of the abundance and biomass of zoobenthos in littoral biotopes.