During a long-term holding in tanks (1 year) without feeding, male winter-form Russian sturgeon from Volga River were investigated at the beginning of anadromous migration in the spring (gonads far from maturity) until maturation the following spring. An increase of testosterone, 11-ketotestosterone, total protein and cholesterol serum concentrations was observed during holding, followed by completion of gametogenesis. After final maturation induced by LHRH-A, androgens, total protein and cholesterol levels decreased significantly; high quality sperm was received.