Abstract—

The composition of fatty acids in the biomass of juvenile Siberian sturgeon (Acipenser baerii) grown in aquaculture to supplement the number of sturgeon populations in the Yenisei River was studied. To study the dynamics of fatty acids composition during growth, juveniles were studied at different stages of postembryonic development: during periods of endogenous and exogenous nutrition. It was found that the food source has a significant influence on the composition of fatty acids in the juvenile biomass. Saturated and monounsaturated fatty acids are used by juvenile Siberian sturgeon as energy sources for growth and development. Polyunsaturated fatty acids and docosahexaenoic acid (DHA) tended to accumulation in biomass from the prelarva stage up to the fingerling stage. The content of eicosapentaenoic acid (EPA) and DHA (mg g^–1) significantly decreases by the fingerling stage due to a decrease in the total content of fatty acids in the biomass of juvenile sturgeon. However, the levels of EPA and DHA in the biomass of Siberian sturgeon fingerlings before release into their natural habitat were relatively high, which may contribute to the development of the necessary adaptive responses and a high survival rate of juveniles.