Oogenesis of the Siberian sturgeon (Accipenser baerii Brandt, 1869) in the conditions of an industrial enterprise
The presented materials consider the results of studies of the reproductive system and oogenesis process during the inter-spawning interval of Siberian sturgeon under industrial farm conditions with the average annual sum of the warmth of5600 degree-days. It has been established that with this sum of warmth, female Siberian sturgeon mature by the sixth year. Oogenesis between spawning intervals may have different duration. Some females, even having passed the process of resorption of sexual products, and after spawning, can mature for the next year, another one miss one or two spawning periods. Decrease of the annual sum of warmth to 4200 degree-days causes shifts ofsexual cycles for two spawning seasons or more, to 3000 degree-days -for at least three spawning seasons. In Siberian sturgeon females, a seasonal dynamics of the increase in the plasma protein level from spring to autumn is traced within each stage of sexual maturity; the increase in the plasma protein and triglycerides in the blood also occurs as the sexual products mature. These indicators can be a reference point for assessing the level of oocyte development in females of Siberian sturgeon.