GROWTH DYNAMICS OF JUVENILE FRESHWATER FORM OF ARCTIC CHAR SALVELINUS ALPINUS (L.) IN THE CONDITIONS OF INDUSTRIAL FISH FARMING

The purpose of research is to study the growth dynamics of juvenile freshwater Arctic char in the conditions of an industrial fish farm. Objectives: to study rearing conditions, dynamics of weight, body length and safety of juveniles when fed with trout food. The object of the study was juveniles of the freshwater form of Arctic char Salvelinus alpinus (L.) of the Taimyr Peninsula, generation 2022 (n = 2892), obtained at the industrial farm of Maltat LLC. The study was carried out in a fish breeding farm in the city of Divnogorsk near the dam of the Krasnoyarsk hydroelectric power station and at the Department of Breeding, Genetics, Biology and Aquatic Bioresources of the Federal State Budgetary Educational Institution of Higher Education Krasnoyarsk State Agrarian University. The work was carried out according to the method of growing salmon fish using a combined method. Observations of the growth of char were carried out in January–August 2023. The fish were placed in a pontoon cage in the downstream of the Krasnoyarsk hydroelectric power station at a distance of 0.8 km from the dam. The depth of the cage is 4 m, the area is 36 m2. Feeding was carried out with trout feed from the Coppens company: Coppens PRE GROWER-18 2.00 mm for fish weighing up to 25 g. The amount of feed received by the juveniles was 1.5 % of the weight of the fish. Control catches were carried out monthly; the weight of at least 25 specimens was determined by random sampling. When reared in cages, the char grew intensively in the spring and summer, and by September the weight of the fry was 51.8 g and the length was 160 ± 3.59 mm. The survival rate of juveniles when fed with trout food was more than 92% throughout the entire study period.