The article presents analysis of material and results of their own studies on changes in the permeability of cellular structures, organs and tissues in carp, which is of great importance in determining age-related indicators. The cells permeability in liver and gonads estimation was carried out under the experimental base of VNIIR on two carp genotypes during the pre-spawning period. The carp groups taken for analysis differed significantly in their genotypes. In females of the Khrapunov group the fecundity was 2023.0 thousand units, while the number of oocytes filled with yolk was only 0.7%, in the Ostashevsky ones - 1370.0 thousand units and 8.6%, respectively. During estimation the chemical composition of the generative tissue in females and males it was established that the cholesterol and lecithin content in males is higher than that of females, while feeding dependence is observed, especially on the amount of protein in the diet. For example, in females on protein diet contained less glycogen in gonads than on females on carbohydrate diet. Lecithin and cholesterol are higher in males than in females, which corresponds to increasing the Gyurdy Ratio (estimation of cell membrane strength). In spermatogenesis the content of phospholipids and cholesterol in the liver was decreased less than during ovogenesis. This indicates a lower level of synthetic processes in the milts compared with the ovaries. The cholesterol content in sperm is higher than in caviar in 19.6 times, and phospholipids almost doubled. With increasing age, the Gyordy Ratio for caviar decreases, for sperm it increases, the percentage of caviar fertilization increases. As the body age metabolism deteriorates, cellular permeability decreases (the ratio of lecithin and cholesterol changes significantly). At the same time, the permeability of cells in different organs and tissues varies and depends on living conditions, especially feeding and to some extent on the origin. In fish the gross productivity decreases as growth slows down and more energy is spent on adaptation to environmental conditions.
