Cytogenetic profile of different groups of the Halych carp in conditions of industrial aquaculture in Subcarpathia ponds

Purpose. To analyze age and seasonal dynamics of the cytogenetic parameters in different age groups of Halych carp under conditions of industrial cultivation. Methodology. Blood sampling for smear preparation was performed from the caudal vein. The smears were preserved in methyl alcohol and stained using the Romanowsky-Giemsa solution. Further analysis was performed under a Primo Star Zeiss microscope at 1000x magnification. The erythrocyte frequency from the micronucleus, single-nucleus lymphocytes from the micronucleus, dual-nucleus lymphocytes, and apoptosis were counted in the smears. The data obtained was measured in ppm (‰). Findings. Erythrocytes with micronuclei in different age groups of the Halych carp ranged from up to 2.7 ‰ ± 0.4 - 4.0 ‰ ± 0.7. The number of lymphocytes with micronuclei was 2.0 ‰ ± 0.4 - 2.4 ‰ ± 0.2. Dual-nucleus lymphocytes in the Halych carp ranged from 2.0 ‰ ± 0.2 to 2.7 ‰ ± 0.3. As a result of cytogenetic analysis, a 11% decrease in the level of cells with apoptosis in age-3 Halych carp compared to young-of0the-year was detected. After wintering, erythrocytes with micronuclei in age-1 and age-2 carp were recorded to be within 2.7 ‰ ± 0.5 - 3.1 ‰ ± 0.6. The incidence of lymphocytes with micronuclei in the Halych carp decreases, while this parameter in age-2 fish decreased by 8% and amounted to 2.4 ‰ ± 0.2. Dual-nucleus lymphocytes in the Halych carp after wintering ranged from 2.9 ‰ ± 0.1 to 3.3 ‰ ± 0.2. As a result of a comparative analysis of cytogenetic parameters of age-1 and age-2 carp, a significant difference in the number of lymphocytes with dual nuclei was found (P ‹0.01; ts = 3.57). The results of the studies show that an increase in this parameter was triggered by rapid growth of fish seeds in pond conditions. Originality. For the first time, the variability of the cytogenetic apparatus of different age groups of the Halych carp at different stages of the technological process in industrial cultivation was analyzed. Practical value. The results obtained can be used for further breeding work with the Halych carp in the region.