The influence of artificial ecosystem on the reproductive quality of sturgeon in aquaculture

One of the promising areas of sturgeon aquaculture is growing in closed recirculation systems, allowing to create stable environmental conditions for optimal growth and maturation. In the present work results of researches on influence of an artificial ecosystem on the reproductive quality of starlet are represented. They indicate that when growing fish in a controlled environment, the speed of growth and development of the reproductive system of sturgeon increases in comparison with natural. This allows to obtain mature males over 21 months, females over 31 months of cultivation. The study of the development of the gonads of the sterlet reared at a stable temperature, have shown that females at the age of 18 months, the oocytes were at the start of the second stage of gonad maturity at 22 months - on the second stage of maturity in 26 months - in the third, and 30 months of gonads of females were completed in the fourth stage of development. When using a regulated hydrological regime of females re-mature in 12 months, while the natural thermal regime need to contain up to 18-20 months. As a result of researches, it is established that the first pre-spawning interval with a stable thermal regime is the greatest, the subsequent interval is reduced by 50-60 days, after the third spawning interval time between spawning stabilize that is associated with the biological characteristics of sturgeons. With age there is an increase mineralogic periods. Sterlet grown in artificial conditions, the overall chemical composition of the body was characterized by a large amount of protein and fat. Assessment of the physiological state of sterlet reared in a controlled water environment, showed that the main investigated parameters of blood of fishes corresponded to the biological norm for individuals of these ages. It was found that when re-maturation in females of sterlet increase fertility, output, as well as the size of the eggs, which leads to more progeny that will be more viable compared to the first spawning.