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

Abstract

Stressful situations decrease the growth rate and survival rate of fish, thus, the search for ways to reduce their adverse impact is relevant. The purpose of the research – to evaluate in aquaculture conditions the effect of different concentrations of vitamin-amino acid complex “Chiktonik” on the growth and survival of larvae and fry of African clarius catfish (Clarias gariepinus B., 1822) after stressful situations. The stressful situation for the fish arose from significant fluctuations in the content of ammonia, nitrites and nitrates in the water environment of the closed recirculation aqua system during the period of start-up of the biological filter, until the equilibrium was established. A series of experiments were performed, during which it was established that the addition of the drug at the rate of 1 ml per 1 kg of feed accelerates the growth of fish in experimental variants compared to the control. Experimental use of high doses of the drug (5, 15, 30 and 45 ml/kg of fodder) initially inhibited the growth of fish body weight, 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 the control values in the future. The positive effect of the vitamin-amino acid complex “Chiktonik” on the survival of young clarius catfish at the stage of completion of the larval period of life and in the early stages of the fry period was established. In the experiment with older fish, which were fully developed fry, such an effect of the drug was not observed: the survival rate of fish was at the same level both in the experiment and in the control. Therewith, it was established that the fry reacted worse to higher doses of the drug compared to the grown larvae. The growth rate of fry after using high doses of the drug did not equal that of fish from the control group within a month after the experiment, unlike younger fish. In general, the expediency and safety of the practical use of the drug “Chiktonik” for young clarius catfish as a fodder additive at a dose of 1 ml/kg of fish fodder have been proved