Functional state of the organism of the hybrid Russian sturgeon × Siberian sturgeon (Acipenser gueldenstaedtii × Acipenser baerii) after winter in cages in Volga Delta

Two-year-olds (15 individuals) and five-year-olds (15 individuals) of the Russian sturgeon × Siberian sturgeon (Acipenser gueldenstaedtii × Acipenser baerii) hybrid, kept in net cages in the Volga delta, were studied after wintering in order to establish the functional state of the organism according to the complex of indicators of the erythron system and metabolism substances. The results of the performed study found that the erythron system in five-year-olds is characterized by a higher content of erythrocytes and blood hemoglobin (0.58 ± 0.01×10 12 l –1 and 64.98 ± 1.29 g/l, respectively), compared with two-year-olds (0.49 ± 0.02×10 12 l –1 and 64.98 ± 1.29 g/l, respectively).The serum iron content in both groups was the same. A higher content of total protein and albumin in the blood, as well as a greater activity of ALT were found in five-year-olds, compared with two-year-olds. Thus, the content of total protein and albumin in blood serum in five-year-olds was at the level of 48.23 ± 1.54 and 21.58 ± 2.34 g/l, respectively, and in two-year-olds — 32.42 ± 0.92 and 13,84 ± 0.61 g/l, respectively (p < 0.05). The activity of serum ALT in five-year-olds was 1.07 ± 0.06 μkat/l, and in two-year-olds — 0.85 ± 0.03 μkat/l (p < 0.01). Serum cholesterol in five-year-olds (3.94 ± 0.04 mmol/l) and two-year-olds (4.4 ± 0.08 mmol/l) did not differ significantly (p > 0.05). The content of serum triglycerides in five-year-olds (4.50 ± 0.49 mmol/l) and in two-year-olds (5.36 ± 0.45 mmol/l) did not differ significantly (p > 0.05). The study of carbohydrate metabolism revealed a pronounced variability in the glycemic index in the younger age group (coefficient of variation 44.7 %) with an average blood glucose value of 2.69 ± 0.31 mmol/l. The blood glucose content of five-year-olds was higher than that of two-year-olds — 3.84 ± 0.24 mmol/l (p < 0.05). The established parameters of variation and the age specificity of the indicators of the erythron system, protein, lipid and carbohydrate metabolism can be used to assess the state of physiological adaptation of the hybrid after wintering in cages in the Volga delta.