Morphopathology of the Prussian carp (Carassius auratus gibelio Bloch, 1782) liver under the effect of allyl acetate

Purpose. To assess the liver parenchyma of Prussian carp based on the analysis of histological parameters of the organ, to establish the level of the effect of alylacetate on the physiological status of fish and the degree of their damage. To determine the prospects for using the obtained results in ichthyological and ecological practice. Methodology. The primary materials were obtained in the summer of 2024 in the Ingul River, city of Mykolaiv. The processing of histological samples was performed at the laboratory of histology, cytology and embryology of the Petro Mohyla Black Sea National University in accordance with generally recognized manuals and the author’s methodology for histological diagnosis of fish tissues. Findings. The study showed that uner the action of allyl acetate, significant changes occur in the marginal and medial zones of the organ in the form of a shift in a certain function, which leads to a change in intracellular metabolism and narrow cellular specialization. With the potential effect of allyl acetate, the reaction of hepatocytes was manifested in an increase in the lipid content in the cytoplasm. The general effect was visualized through the development of a picture of total lipostasis. Fatty degeneration was accompanied by vascular disorders and hemodynamic disorders, the presence of an inflammatory reaction. Under conditions of prolonged exposure to the toxicant, the number of hepatocytes with two nuclei and nucleoli increased significantly, which was recorded in healthy individuals and was not considered a sign of pathology. Under conditions of prolonged exposure to chemical stress, carcinogenesis was activated in the fish liver. This was evidenced by a characteristic picture of a failure of the moment of transition of the sequence and periodicity of morphogenetic processes, which manifested itself in the form of atypical cellular polymorphism. Originality. New data are presented on the reaction of the histological structure of the liver parenchyma of fish under conditions of technogenic load in the water body. For the first time, a detailed histological analysis of the structure of the organ under conditions of prolonged exposure to allyl acetate has been carried out. Information on changes in liver tissue, which demonstrate the destruction of its adaptive potential, has been supplemented. Practical Value. The information obtained is valuable in morphophysiological studies, as well as in ichthyological and ecological practice in connection with the problem of reducing the vital status of fish under conditions of technogenic loads on water bodies. The use of the obtained data allows for a qualitative assessment of the physiological state of fish and can be used in the process of developing corrective measures for the purpose of environmental protection. Keywords: fish, toxicants, liver parenchyma, marginal zone, medial zone, hepatocyte, nucleus, glycogen, cytoplasm, lipostasis.