Biotechnical aspects of growing clarium catfish in the ras the conditions of the kaliningrad region
In the context of climate change that has occurred over the past 40 years, including in the Kaliningrad region, which are reflected in the increase in average annual air temperature, which indirectly led to an increase in the heat balance of surface water sources, it becomes risky to grow fish (especially cold-loving and oxyphilic) in open fish breeding systems ( pond, cage, direct-flow basin and lake farms) in abnormally warm summer seasons. Therefore, the feasibility of the formation and operation of brood stocks of fish, the cultivation of planting material that is more susceptible to a high background of water temperature, in recirculating aquaculture system (RAS), and salable fish, which has more advanced adaptive mechanisms of homeostasis in open fish breeding systems, is obvious. In this case, we are talking about combined technologies. Recirculating aquaculture system due to the initially formed features, have the ability to influence the growing processes of both planting material and salable fish. When fish is grown only in RAS, it becomes possible to use polycyclic technologies that can increase the yield of fish products by several times, which helps to increase the profitability of production. The purpose of the work was the formation of biotechnological standards at all stages of growing catfish, reflecting the results of the study over a ten-year period. The developed biotechnology covers all stages of cultivation from the formation of the breeding stock and the generation of offspring to the biotechnical features of the cultivation of marketable fish. Based on the real costs of growing commercial fish, the economic efficiency was calculated for the commercial cultivation of catfish.