Prolonged effect of ultra-weak magnetic fields on the growth and development of the muksun Coregonus muksun in the postembryonic period

During the production experiment under the conditions of ultrasonic treatment at the Soba Fish Hatchery (village of Harp, Yamalo- Nenets Autonomous District), studies of juvenile muksun were conducted, which followed the program of compensatory events. The experimental batch of juveniles was treated by a generator of ultra-weak pulsed magnetic fields (UWPMF) during the entire period of rearing. The rearing of juveniles in the closed-circuit water supply unit corresponded to the accepted standards of the fish hatchery. Fry and fingerlings of the control and experimental batches were studied using morphometric, histological and statistical methods. It was found, that the studied morphometric parameters of the experimental muksun juveniles exceeded those of the control batch, but were inferior to it in terms of the degree of mutual correlation. The morphofunctional state of the liver in the juveniles of the experimental batch had better characteristics, the number of nucleoli in the nuclei of hepatocytes was increased, and only a few lipid droplets were present in the basophilic cytoplasm. Significant fatty inclusions were accumulated in the hepatocytes of the control individuals, which indicated the initial stages of fatty liver dystrophy. Gonadoand gametogenesis took place more intensively in the juveniles of the experimental batch during the entire period of rearing. Summarizing all data obtained on the parameters of size and weight, morphofunctional parameters of the liver and generative system of juvenile muksun in the experiment, it is possible to conclude that the juveniles of the experimental batch possessed higher adaptation capacities for existence under natural conditions than the control batch.