Influence of wintering on morphophysiological and chemical indicators of pikeperch Sander lucioperca

Abstract

During the wintering period, sander from their natural habitat and grown in farm conditions undergo changes in morphophysiological and chemical status due to the expenditure of energy reserves of the body and the redistri-bution of nutrients in the muscles and liver. This is expressed in a significant decrease in the content of ab-dominal fat in the body of wild and factory individuals (by 45 and 16%, respectively), muscle fat content (by 26% in wild individuals) and liver (by 59% in wild and 16% in farm fish), vitamin C in muscles (by 56 and 23%, respectively). At the same time, the content of nitrogen–free extractives in the muscles and liver increases many times – by 47 and 31%, respectively, in wild individuals and by 31 and 29% in sander raised in cages. The proportion of monounsaturated fatty acids in the lipids of sander muscles in winter significantly increases and the proportion of polyunsaturated fatty acids (PUFA) decreases, especially eicosapentaenoic (EPA), docosahexaenoic (DHA) and arachidonic, against the background of an increase in the level of these acids in the liver. From the point of view of meat quality, estimated by the content of long-chain PUFA, during the wintering period there is a significant decrease in the nutritional value of caught and raised fish, which is expressed in a 2-3-fold decrease in EPA + DHA in fillets. Such changes are the adaptation of fish to cold temperature conditions during prolonged wintering and are associated with puberty.