The article analyzes the data of long-term studies of sterlet growth in the Kuibyshev Reservoir (watershed of the Volga River) conducted by researchers of the Tatar branch of the All-Russian Research Institute of Fisheries and Oceanography. Significant variations in sterlet length were found not only from year to year, but also in different parts of the reservoir. There have been stated the changes in sterlet population. In recent years, the reservoir has seen an improvement in the growth of sterlet yearlings in comparison with that of fish in the Volga river and in the first years of the reservoir's existence, and a decrease in the growth rate and size of older individuals. It has been found that starlet species in Kama Reaches grow better than in other parts of the reservoir. Fish with fast linear growth is found to increase its percentage, while the part of slow-growing fish decreases.