Topical and trophic structure of midsummer zooplankton in saline rivers in the Elton Lake basin

Abstract

In August 2013, 17 taxa of zooplankton in the rank of species (Cladocera, Cyclopoida, Calanoida, and Rotifera) and three taxa of meroplankton (Mollusca, Diptera, and Heteroptera larvae) were identified in the zooplankton of six small rivers in the basin of Lake Elton with a mineralization of 6–32 g/L. Benthoplankton formed most of the list (45% of species); euplankton constituted only 20%. Three trophic levels were distinguished in the community: peaceful phyto- and bacteriodetritophages, omnivorous animals with different body sizes (<1.5 and 1.5–6 mm), and predators. The effect of salinity on the zooplankton structure, the biotopical distribution of species, the features of trophic relations, and the food supply of predators are discussed.