Hematological indicators of the blood of males and females of the Ukrainian scaled carp breed

Abstract

The research results on hematological indicators of males and females of the Ukrainian scaly breed of carp grown in the conditions of a fish farm in the Dnipropetrovsk region are given. In Ukraine, carp cultivation is becoming an increasingly popular method of commercial fish production. At the same time, the hydrochemical and temperature regimes of the reservoir have important practical significance for the average growth and development of fish since the intensity of respiration, metabolic processes, fish nutrition, motor activity, and resistance to various diseases depend on the chemical composition and temperature of the water. The process of formation of the hydrochemical composition of pond water occurs against the background of climatic changes. Therefore, control of temperature conditions and the physiological state of fish during carp cultivation is an important measure that ensures rational consumption of feed and high growth rates and, in the future, allows to plan of optimal cultivation technology. Therefore, the work aimed to investigate the hematological indicators of blood in males and females of the Ukrainian scaly breed of carp to control their physiological state in the conditions of the hydrochemical and temperature regime of the reservoir of the fish farm. It was established that the main hydrochemical parameters corresponded to the technological standards adopted in fish farming to cultivate carp fish. The hematological parameters of the blood of male and female carp were within the physiological norm. The determined blood composition is natural and characterizes changes in the body of fish according to the season, which reflects adaptation processes in the conditions of seasonal fluctuations in water temperature. Correlative relationships between carp blood's hematological parameters and their keeping temperature conditions were revealed. The pH of the medium (r = 0.28–0.34) has the most significant effect on hematological indicators of carp blood. A positive correlative relationship was established between water temperature and the level of hemoglobin, a color indicator, and the number of erythrocytes and leukocytes in the blood of fish, which was in the range of r = 0.21–0.26. There was a negative relationship between the water temperature indicator and the content of segmented nuclear neutrophils (r = 0.24). The variance analysis of the one-factor complex revealed a significant and most highly probable influence of the conditions of keeping carp on the hemoglobin content, the number of erythrocytes, leukocytes, and the color index of the carp's blood. The share of influence was from 56.14 to 76.90 %. The amplitude of water temperature is essential for favorable conditions for hydrophones and the formation of a natural feed base. In addition, the environment's temperature affects the speed of biological processes in fish. Therefore, the organization of carp feeding, considering scientifically based norms depending on the protein content in compound feed, water temperature, fish weight, and density of its landing, will contribute to ensuring high fish productivity and rational use of feed.