Trophological studies for calculating the receiving capacity in the interests of artificial reproduction of sterlet in the Volga-Caspian Fisheries Subdistrict

The article presents the results of trophological studies of pass-through and riverine fish species in the root channel and delta of the Volga River. The aim of the work was to establish food competitors of juvenile sterlet from artificial reproduction in the places of its release and feeding. As a result, the nutrition spectra and the degree of filling of the digestive tracts of a number of cyprinid, catfish and goby fish species were studied. Based on the conducted studies, the daily rations and the frequency of occurrence of forage organisms in the food of each fish species were determined. The obtained materials are included in the calculation of the receiving capacity and serve as the basis for determining the optimal volume of release of factory sterlet juveniles into the watercourses of the Volga River in the Astrakhan region.