Abstract
In this study, we present the results of scientific work aimed at studying the state of the spawning carp (Cyprinus carpio carpio) population in the middle reaches of the Negreikin River, located on the eastern edge of the Volga Delta, Volga-Caspian fishery subdistrict. The study was conducted mainly in the spring and summer periods from March to August, and lasted until November 2023. The data collected during the study includes studies on the natural reproduction of carp, its age and size composition, growth, and the growth of spawning individuals. All aspects of the reproductive function of the carp have been thoroughly studied and analyzed. Important factors such as age, size, sex ratio dynamics, seasonal and annual maturity, and gonadosomatic index were studied. In addition, the fecundity of female carp and its relationship with body length, weight, and age were studied.