Comparison of fish biological indicators of Clarias gariepinus hybrids grown in ras and pond farming conditions

To improve technologies in the field of commercial cultivation of aquaculture objects and further development of the warm-water aquaculture sector in Russia, we previously undertook breeding methods and approaches to obtain high-quality planting material for a promising commercial object — the African catfish Clarias gariepinus. This article presents, in a comparative aspect, the experience of growing hybrid offspring of African catfish, obtained from crossing two breeds — Mikhailovskaya and Tamanskaya, in a closed water supply system and in a pond farm in the Astrakhan region in the summer. It was shown that hybrid individuals of clariid catfish bred in a pond farm during the feeding period under consideration (from July to September) were characterized by a high specific growth rate and low feed ratio compared to hybrids grown in a recirculation system, respectively, 11.4% versus 9.87% and 0.96 versus 1. Also, based on the results of fishing, over two months of cultivation in a pond farm, hybrids of clariid catfish increased the total biomass by 13 times, while in a recirculating system it increased by 15 times, but the final biomass of fish turned out to be greater when reared in open reservoir (46.875 versus 10.87 kg). It was shown that the final individual mass of hybrid fish cultured in pond conditions was 11.0% higher than the final mass of individuals in the recirculation system. The conducted studies showed that in the climatic conditions of the Astrakhan region (VI fish-breeding zone), a promising direction for aquaculture of African catfish is the feeding cultivation of hybrid juveniles in pond farms. It should be taken into account that in order to obtain marketable fish products (i.e. individuals weighing over 1000 g), it is necessary to use fish seeding material with an average weight of at least 100 g.