Growth and survival of Clarias catfish (Clarias gariepnus B., 1822) at different stages of cultivation with the addition to the fodder of “Chiktonik”

The paper presents the results of an experiment to assess the effect of different concentrations of vitamin-amino acid complex "Chiktonik" on the growth rate and survival of young African clary catfish (Clarias gariepinus B., 1822) after various stressful situations, for keeping fish in aquaculture. In the experiment, the stressful situation for fish arose due to significant fluctuations in the content of ammonia, nitrites and nitrates in the aquatic environment of a closed recirculation aquasystem, which kept larvae and fry of Clarya catfish during the start of the biological filter, before establishing biological equilibrium in the system. Based on the analysis of sources of scientific and technical information, it was found that the drug "Chiktonik" for more than 10 years is used in animal husbandry to normalize metabolism in animals with unbalanced feeding, after stress, mycotoxin poisoning and antibiotic treatment. This information gave rise to the assumption of the possibility of using the drug in aquaculture, for the same purposes. A series of experiments was performed in a closed recirculating aquasystem, during which the effect of different concentrations of the drug "Chiktonik" in fish feed on larvae and fry of Clarya catfish was tested. It was found that the addition of the drug at the rate of 1 ml per 1 kg of feed accelerates the growth of fish in the experimental variants, compared with the control. Experimental use of high doses of the drug (5, 15, 30 and 45 ml/kg of feed) initially led to inhibition of weight gain of fish, but 10-30 days after the experiment, the growth rate of the experimental material was equal to that of the control group of fish and even exceeded control in the future. The positive effect of vitamin-amino acid complex "Chiktonik" on the survival of young Clarya catfish at the end of the larval period of life and in the early stages of the fry period was established. In an experiment with older fish, which were fully formed fry, such an effect from the use of the drug was not observed: the survival of the fish was at the same level, both in the experiment and in the control. At the same time, it was found that the fry respond less well to high doses of the drug, compared with adult larvae. Thus, the growth rate of fry after the use of high doses of the drug was not equal to that of fish from the control group within a month after the end of the experiment, in contrast to younger fish. In general, the feasibility and safety of the drug "Chiktonik" for young Claria catfish as a feed additive at a dose of 1 ml / kg of fish feed has been proven. It is considered promising to continue research in this direction, using as research material fish of older age groups, including - repair and breeding stock of Claria catfish.