The peculiarities of sterlet gametogenesis at cultivation in the conditions of the recircular systems are considered. As a result of the research of development of reproductive system of sterlet at preserving in an installation with an adjustable thermal regime it was established that at daily average temperature of 21.5 oС the time of full maturing of sexual products makes 19 800-22 252.5 day-degrees, that is reached for 29-32 months of cultivation in recircular system. At a natural thermal regime the necessary quantity of warm can be reached only for 4.0-5.5 years.

The effectiveness of cyanocobalamin application for breeders' injection and eggs' treatment is investigated. The breeders of Russian sturgeon (Acipenser gьldenstдdti Brandt), stellate sturgeon (Acipenser stellatus Pallas), starlet (Acipenser ruthenus Linnaeus), and also their eggs, larvae and fry have been used. The cyanocobalamin introduction to females before spawning significantly increases their piscicultural biological characteristics. The indices of female maturation are increased to 7-16 %, of egg fertilization to 10-17 %, output of free embryos 20 %. During the cyanocobalamin processing of eggs the output of free embryos becomes higher by 18 %, survival rate of prolarvae by 20 %, than in control. In the processed eggs there is 3-6 times less deflection in development. In 40 days the weight of fry, grown up from the processed eggs, was 14 % higher, than in control.