Prussian carp Carassius gibelio (Bloch, 1782) in conditions of decreasing runoff of coastal waters and salinization of the Sea of Azov

The biology and ecology of the Prussian carp Carassius gibelio in the water bodies of the Don River delta and Taganrog Bay are considered. This species is characterized by high ecological plasticity and the ability to adapt to various water conditions, including anthropogenic impact. Its high tolerance to changes in temperature and water salinity is noted, which allows it to successfully populate a variety of water bodies, including sea bays. Particular attention is paid to the commercial value of the species. Despite the decline in numbers in recent decades due to anthropogenic impact and changes in the hydrological regime, the Prussian carp remains one of the most important fishery objects in the region. In 2007-2018, its share in catches from the Sea of Azov ranged from 28 to 53%. An increase in the salinity of the waters of the Sea of Azov, which is a consequence of a decrease in the flow of the Don River, leads to a decrease in feeding areas and the number of Prussian carp, which inevitably entails a change in the amount of its catches. The result of the hydrological and hydrochemical changes that occurred was the forced migration of part of the population of Prussian carp from the western waters of the Taganrog Bay to the Don Delta. The state of the C. gibelio population in the eastern part of the Taganrog Bay and in the Don Delta in 2022 was studied. The characteristics of the physiological state of fish, the assessment of the state of the gonads, and size and mass parameters are given.