Results of artificial reproduction of sturgeons reared in cages with natural temperature regime of water bodies of the forest-steppe zone of Ukraine

Purpose. To determine main the technological parameters of artificial reproduction of sterlet (Аcipenser ruthenus) and Siberian sturgeon (Acipenser baerii) with a combined use of industrial aquaculture methods. Methodology. The material for the study were brood sterlet and Siberian sturgeon reared in cage conditions in a water body with natural temperature regime of the forest-steppe of Ukraine. The experiments were performed at a regulated water temperature regime at different periods of the spring (March-May) with the use of natural gonad-stimulating hormones for the stimulation of the maturation of sexual products in fish. During the process of the preparation of brood fish for fish breeding works, a recirculating water supply facility was used. The determination of technological parameters and study of physical-chemical factors of the environment were performed according to generally accepted methods. Findings . At a water temperature of 14-16оС, high efficiency of gonad maturation was observed in sterlet and Siberian sturgeon females with mean weight of 2.8 and 11.6 kg, respectively. The mean weight of eggs obtained from the brood fish was 0.45 kg in sterlet and 1.48 kg in Siberian sturgeon. The mean working fecundity was 43.29 thousand eggs in sterlet and 83.75 thousand eggs in Siberian sturgeon at a relative working fecundity of 15.44 and 7.49 thousand eggs/kg of fish body weight, respectively. During the process of egg incubation, development of fish embryos at the gastrulation stage was on average 87.17% in sterlet and 84.50% in Siberian sturgeon. The output of free embryos of both species from the quantity of embryos on the stage 15 of embryonal development was close to 83-84%. Originality . Peculiarities of the production of embryos from brood sterlet and Siberian sturgeon with a combined use of different methods of industrial aquaculture in the conditions of a sturgeon farm of the forest-steppe physical-geographical zone of Ukraine have been studied. Practical value . The results of the study are of interest for the devolvement of modern methods of sturgeon aquaculture in the conditions of an industrial type farm.