Composition and Structure of Zooplankton Community in Lake Pleshcheyevo, Russia

The composition and abundance of zooplankton were studied in 2012-2016 in the deepwater stratified mesotrophic Lake Pleshcheyevo, Yaroslavl oblast (Russia). During the study period, 130 species of rotifers and crustaceans were recorded in the lake. The plankton abundance and biomass during the study period were lower or close to the values indicated for 1979-1996. The open littoral of the lake was more often characterized by the low abundance of zooplankton compared to deeper areas (depths exceeding 4 m). Interannual variations in the total abundance and biomass of zooplankton in different seasons of the year were observed, caused by the climatic features of different years and different times of sampling. The composition of the dominant species of rotifers and crustaceans in 2012-2016 was close to that indicated earlier in 1979-1996. Synchaeta lakowitziana, S. kitina, Diaphanosoma mongolianum, and Thermocyclops oithonoides were noted for the first time as dominant zooplankton species in the lake.