Full-system study of neuroendocrine regulation of fish reproduction. 3. To improve biotech managing methods of valuable fish species reproduction

Abstract

According to presently used biotechnics of salmon farm reproduction, producers are withdrawn (fishing out) from spawning (fish spawning grounds), and the survival rate of one-year-old farmed juveniles in nature (in the form of “spawning return”) is half of the standard. To exclude these most important biotech imperfections, a new biotechnological approach based on the identification and use of species potencies of reproduction, survival and growth in an adequate species-specific complex of optimal habitat conditions are developing. The purpose of our full-system research is to develop effective biotechnics for the artificial reproduction of salmon fish populations in the North-West. To refine the previously developed basic full-system method of reproduction of salmon and sturgeon fish populations to the possibility of its industrial use is the main task of the work. The new “Method for production offspring of sturgeon and Atlantic salmon in seawater” includes the maintenance of brood-stock and the production of offspring of migratory fish in a wide range of salinity of the brood pond. To do this, at the onset of spawning temperatures, producers are sorted according to the degree of readiness for spawning and physiological (hormonal) stimulation of the mature producers gonads maturation are carried out with a natural hormonal preparation — an isolated anterior pituitary lobe, in established species temperature-dependent doses. And immature producers are subjected to environmental (ecological) stimulation of maturation by a periodic influx of fresh water and, upon reaching readiness for spawning, they are stimulated by preparate of the isolated anterior pituitary lobe. The method provides the efficiency increase of natural and artificial reproduction of migratory fish by expanding the possibilities of obtaining offspring from producers in the marine habitat.