BIODIVERSITY AND CURRENT STATE OF ZOOPLANKTON OF THE SYRDARYA RIVER

This article describes the species structure and quantitative indicators of zooplankton communities of the Syrdarya River within the Kyzylorda and Turkestan regions. In 2023, 34 species of invertebrates were found in the zooplankton of the Syrdarya River, including Rotifera – 15, Cladocera – 9, Copepoda – 8 species. In addition to representatives of the main groups, larvae of bivalves and chironomids were found in the plankton. During the study, the water temperature in the periodic aspect ranged from +21.5 degrees to +16.3 degrees. The most frequently encountered species of zooplankton invertebrates were identified in the spring and autumn periods of research. There is a decrease in the quantitative indicators of organisms in autumn compared with spring, which is associated with a decrease in water temperature, which negatively affects the occurrence of thermophilic invertebrate species. In spring, the dominant role in quantitative terms belongs to copepods associated with the development of large crustaceans Cyclops vicinus., and in autumn the leading position was occupied by branchous crustaceans, with the superiority of crustaceans Daphnia longispina and D. galeata.