Abstract
<jats:p>The zooplankton communities of continental water bodies in Eastern Siberia, and particularly those, of the Magadan region, are among the least studied. The objective was the inventory of the species composition of microcrustaceans and the identification of the main environmental factors determining the community structure. A total of 59 species of Cladocera and Copepoda were identified, including nine new for the region and one new for science. The number of species at different sites (basins of the Ola, Yana, and Kolyma Rivers) varied. The observed differences in community structure can be attributed to their geographical locations and the associated complex of climatic, hydrological, hydrochemical, and phytocenotic factors. The investigated fauna is represented by the widespread Holarctic and Palearctic species, as well as the Beringian endemics. However, the ratio of such species and the total number of species differ in different collection areas.</jats:p>