| Abstrakt: |
The hormonal and ultrasound screening have been performed for the females of Siberian sturgeon Acipenser baerii reared under continuous grower feed and high stocking density in a recirculating aquaculture system. Infertile females represented 33.3% of total number; they did not mature even at the age of 10 years, carrying the ovaries at the gonad maturation stage IIb (lipid) at the time of the study. The pathologies in liver were presented in 42.8% of such females together with abnormally high concentrations of androgens in the blood serum compared to normally maturing fish. Presumably, high stocking density (40 kg/m2) and long-term supply with grower feed (protein content 45%, fat content 15%) were the main reasons reducing the reproductive characteristics of spawners and increasing the share of infertile and obese females. For the first time, the concentration of dehydroepiandrosterone sulfate (DHEA-S) has been used for screening of sturgeon breeding stocks; DHEA-S is a popular marker in medicine for the diagnosis of human female infertility against the background of high concentrations of androgens. Testing of immature Siberian sturgeon females using this hormone testified to a higher sensitivity of this method compared to testosterone measuring. [ABSTRACT FROM AUTHOR] |
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