A comparative analysis of fingerlings of H. huso L., A. stellatus Pallas and their hybrid, as well as of 2 yr old hybrid individuals, and the degree of character variability and inheritance was performed in order to determine age-related morphometric characteristics of these fishes under controlled growth conditions. An artificial fertilization of H. huso eggs with A. stellatus testes was performed in a fish hatchery in the lower reaches of the Don River, USSR. The hybrids were grown in ponds of Aksai Fishery Corporation. The data obtained were treated statistically. Hybrid fingerlings differed from their parent forms in their external traits. They were larger in size and weight than fingerlings of parent forms. They were intermediate between H. huso and A. stellatus with respect to condition. Hybrids inherited a phenotype intermediate between the 2 crossed species with regard to most characters.