The literature data on the etiology and pathogenesis of swim bladder inflammation (SBI) in various fish species have been highlighted in the paper. The main goal of this work was to analyze the impact of the disease on the physiological status of the body of the yearling carp, the state of the antioxidant defense system, and the content of lipid peroxidation products (LPP). The yearling Liubyn scaly carps, with an average weight of 40 g, which were grown in the ponds of the Rivne fish and reclamation station, were selected for experimental research. During control catches and ichthyopathological examination of forty fish, inflammation of the swim bladder was detected with an intensity of 35 %. During the pathological autopsy of this yearling carp, thickening of the walls of the swim bladder with purulent exudate, atrophy of the posterior lobe, and hyperemia of internal organs was found. Data on the content of lipid peroxidation products (LPP) and the state of the antioxidant system (AOS) in the cells of the hepatopancreas and skeletal muscles of this year's carp with SPM have been presented. It was determined that in the hepatopancreas of fish with the swim bladder inflammation, primary and secondary LPP products accumulate, and the activity of AOS enzymes decreases. The increase of diene conjugates in the hepatopancreas of the diseased fish was revealed by 11.8 % compared to the control group, and the content of TBC-active products by 29.8 %. The level of SOD activity is 13.5 % lower in the fish affected by SMP than in the control group. Catalase activity in the hepatopancreas of the diseased fish increases by 11.7 % compared to the control group. There was a 45.5 % decrease in superoxide dismutase activity in the skeletal muscles of fish affected by SBI and a significant increase in the level of catalase (Р < 0.01) compared to the control group. Pathogens that cause diseases of the swim bladder cause also have an inhibitory effect on the activity of enzymes of the antioxidant system, and the content of products of lipid peroxidation increases.

Introduction. In the conditions of anthropogenic pollution of water, environment-safe drugs and implementing of immunomodulatory drugs are becoming increasingly common. Schemes of their use in fisheries are being developed. The article presents and analyzes the potential use of biologically active additives (BAA), namely probiotics, prebiotics and yeasts, both domestically and internationally produced, in terms of their effect on the fish body. Materials and methods of research. Search for literature data on the use of biologically active substances in fish farming, namely probiotics, prebiotics and yeast. Research results. Considering the negative impact of prophylactic and therapeutic use of antibiotics in aquaculture, the use of dietary immunostimulants has been proposed as an alternative to antimicrobial drugs. In this sense, functional dietary supplements, including pre-, probiotics and yeasts, are receiving increasing attention as an environmental strategy to improve fish health. Probiotics are the objects of comprehensive scientific research and an important product on the world market. The use of probiotics as biocontrol agents in aquaculture is increasing. The benefits of such additives include increased nutritional value, inhibition of pathogens and enhanced immune response by increasing white blood cells and phagocytosis. They improve the quality of the growing environment, protect fish from biological hazards, and modulate physiological processes that ultimately contribute to the health and welfare of fish in aquaculture. Probiotics also enhance growth performance and feed utilization in aquatic animals by increasing the activity of digestive enzymes. The beneficial effects of prebiotics are due to by-products resulting from the fermentation of intestinal commensal bacteria. Among the many health benefits attributed to prebiotics is the modulation of the immune system. They directly enhance the innate immune response, including activation of phagocytosis, neutrophils, alternative complement system, and increased lysozyme activity. Another environmentally friendly product that has been proposed as a dietary supplement is yeasts. Research on yeast products in fish diets has focused on their role in nutritional and functional supplements that contribute to the immune responses and gut health of fish. Conclusions. Various studies of pro- and prebiotics in fish have shown the following results: effects on growth, gut microbiota, resistance to pathogenic bacteria and parameters of innate immunity such as alternative complement activity (ACH50), lysozyme activity, natural hemagglutination activity, respiratory burst, superoxide dismutase activity and phagocytic activity.All the above studies demonstrate that the addition of nutritional supplements to feed, such as immunostimulants, is an alternative method for the prevention and control of various diseases in aquaculture.