PRELIMINARY RESEARCH ON EPIGENETIC PROGRAMMING OF CONTROLLED CARP REPRODUCTION THROUGH MANIPULATION OF ENVIRONMENTAL CONDITIONS

The study investigated the selective reproduction of common carp (Cyprinus carpio) under controlled temperature and oxygen conditions, aiming to evaluate the impact of environmental parameters on fecundity, incubation, and offspring survival. The control group, maintained under optimal conditions (23 °C, 6.5 mg/L O₂), exhibited the highest reproduction rate and ahatching rate of 70%, confirming its role as an experimental benchmark. In Experimental Variant I (26 °C, 5 mg/L O₂), moderate stress resulted in a reduction in the number of active females, decreased oocyte viability, and a hatching rate of 45%. Experimental Variant II, characterized by severe hypoxia (26 °C, 1.5 mg/L O₂), produced the lowest hatching rate (35%)but revealed individuals with valuable potential for breeding programs aimed at stress tolerance. Sequential evaluations showed a direct correlation between dissolved oxygen depletion and reduced survival rates, with values of 75.6% in the control group, 48% in Variant I, and 36% in Variant II. At the end of the experimental period, the control group maintained growth consistent with standard technological parameters, while the experimental variants demonstrated adaptability to restrictive conditions, confirming their relevance for the selection of genetic lines resistant to hypoxia and elevated temperature. The results underscore the importance of maintaining optimal oxygenation and temperature regimes in the artificial reproduction of carp, while also highlighting the potential use of controlled stress as a tool for epigenetic programming and genetic improvement of aquaculture species.