The expansion of the scale of the formation of brood herds of sturgeon, including one of the most widespread species cultivated in industrial aquaculture in Russia - the sterlet Acipenser ruthenus Linnaeus, 1758, requires continuous improvement of reproduction technologies and the development of technological methods for controlling the processes of spermatogenesis in warmwater farms. For this purpose, complete information is needed about the course of spermatogenesis processes in fish and their dependence on abiotic and biotic environmental factors [3–5; 14–17].
At early stages I-II of maturity, the testes are anatomically formed, primary spermatogonia are present from the germ cells and in the state of mitotic reproduction, and sex differentiation in fish occurs in the formed gland during the transition of the mitotic cycle of development to the meiotic one, which is characteristic of the beginning of stage III of testicular maturity [9; 11].
The rate of development of germ cells in gametogenesis in fish is significantly influenced by the temperature factor, and the slowdown in the rate of development of germ cells, as a rule, falls on stage II of testicular maturity and at the beginning of the period of sex differentiation, which is characterized as an attempt to spermatogenesis [6; 12; 15; 16].
The development of the reproductive system in males under different environmental conditions, natural, combined and industrial, affects the reproductive qualities of sturgeon fish, showing variability in the duration of the course of maturation of germ cells in each case [7; 10; 19].
The analysis of the features of the process of spermatogenesis and reproduction rhythms in sturgeon fish will show the ways of managing in artificial conditions of farms with controlled water temperature in the terms necessary for fish breeding enterprises for obtaining sexual products.
The fish was grown in the industrial enterprise of the Konakovsky department of the freshwater fishery branch of the “VNIRO” (“VNIIPRKh”) with an average annual amount of heat of more than 5,600 degree days. Various groups of fish ranging in age from underyearling to four-year-olds were taken for research. To analyze the development of germ cells in male sterlets of the Volga population, histological methods were used as highly informative, sensitive and photodocumentary [8; 13].