LAUSR

The content of total moisture, dry matter, lipids, proteins, ash, and nitrogen-free extractive substances in the muscles, liver, and gonads have been analyzed for pike-perch Sander lucioperca and sichel Pelecus cultratus of Gorky Reservoir. In the muscles of the females of these fish species, the products of the lipid and protein metabolism accumulate more intensively than in males. In both pike-perch and sichel, the accumulation of lipids, proteins, nitrogen-free extractive substances in the liver, as well as protein and nitrogen-free extractive substances in the gonads, are similar in males and females. During the maturation of pike-perch and sichel, substances of various chemical nature are assimilated in the gonads. The nature of the accumulation of metabolic end products in the muscles and liver with age is similar. In the sichel muscles, a direct dependence of the lipid content on age is found, while it is the opposite in the pike-perch muscles, which may be due to the peculiarities of the fish nutrition.