Adaptive response of koi carp (Cyprinus carpio koi) to low and high temperatures in experimental conditions

Abiotic factors of the water environment are essential for the life of hydrobionts. They are determined by two main criteria – the intensity of the impact factor and the tolerance of each species. The work aims to substantiate the adaptive capabilities of this summer's koi carp (Cyprinus carpio koi) under the influence of low and high temperatures, to compare the coefficients and breathing rhythms of the research objects. Experimental research was carried out in the conditions of the aquarium-basin complex of the Department of Ichthyology and Zoology of the Bila Tserkva National Agrarian University. Two aquariums with a volume of 800 dm3 were used for the experiment. Individuals of approximately the same size and weight (25–30 g) were divided into two groups. The first group of fish was kept at a temperature of 11–14 °C for 30 days, and the second group was kept at a temperature of 24–29 °C for 30 days. During the experiment, there were 20 specimens in each aquarium. This summer koi carp (Cyprinus carpio koi). Feeding was carried out with Alltech Coppens Pre Grower feed – 15EF, 2.0 mm. Composition of ingredients (%) per 1 g of feed: raw protein – 50; fats – 15; fiber – 0.80; ash – 8.6; phosphorus – 1.21. In experimental conditions, changes in consumption of koi carp (Cyprinus carpio koi) O2, the release of CO2 and NH3 (per 1 g of live weight in 1 hour) at temperatures of 11–14 °С and 24–29 °С were studied. The consumption of O2 and the release of NH3 in these summers of koi carp at low and high temperatures were compared. The change in respiration (RR) and ammonia (N/O) coefficients in “warm” and “cold” fish with increasing temperature was analyzed. The breathing rhythm and oxygen per breath at different environmental temperatures were determined. Based on the obtained data, the adaptive reactions of this year's koi carp to the influence of reduced and increased temperature indicators of the aquatic environment were determined.