Comparative characteristics of the development of germ cells in Siberian sturgeon and sterlet in the second year of cultivation in the spring and summer seasons, obtained using cryopreserved and native sperm in industrial farms

The research was carried out in the Konakovsky department of the Freshwater Fisheries branch of the VNIRO Federal State Budgetary Budgetary Institution (VNIIPRH) and is a continuation of previously performed work [2]. The effect of cryopreserved and native sperm on the development of germ cells in domesticated forms of Siberian sturgeon and sterlet in the second year of cultivation in the spring and summer seasons is shown in comparative terms. The analysis of fish farming data in the summer continues to show a correlation of body weight with the mass of the left, right and gonad length. In the spring season, the sex of females and males is determined by anatomical differentiation, and in the summer visually by the state of the gonads at autopsy. When using cryopreserved sperm (experiment) and native (control), the development of germ cells is similar in Siberian sturgeon and sterlet. In the summer, as in the spring season, regardless of body weight, histological analysis of germ cell development shows a regular process of sequential gametogenesis. In the spring season, the females of the Siberian sturgeon and sterlet have the first stage of gonad maturity, and mitotic reproduction of oogonia takes place in the nests of the egg plates. In the summer season, Siberian sturgeon and sterlet have the II semifat stage of maturity, which characterizes the cytological level of gonads. Males of Siberian sturgeon and sterlet in the spring and summer seasons are characterized by a similar pattern — anatomical differentiation of sex. In the gonads of the first stage of maturity, spermatogonies multiply, which shows a regular spermatogenesis. In the experimental and control groups of Siberian sturgeon and sterlet, many blood cells, histiocytes, are present in the parenchymal tissue of the gonads. They carry out resorption processes, fulfilling the protective function of the body, absorbing and freeing the gonad from unnecessary and outstripping cells in the body, including ensuring synchronicity at certain stages of germ cell development.