Comparative characteristics of morphofunctional state of organs in black-back herring (Alosa kessleri kessleri) caught in different years

Abstract

The purpose of the research was to consider pathological characteristics of tissues and organs of black-back herring (Alosa kessleri kessleri) in different years. Results of the comparative analysis of pathohistological changes 
 in the organs were taken into account, since this method allows revealing pathological changes in herring organs and tissues, and comparative analysis of histomorphological parameters of black back herring in different years allowed determining changes in the degree and level of a pathological process in the course of time. There were studied the matured species of black back herring Alosa kessleri kessleri (Grimm) caught for analysis during the spawning run in the Volga River in 2014 and 2021. Six hundred of histological sections of organs (liver, kidneys, spleen, intestines, and gills) in 37 species were prepared and analyzed. The species selected for the study were 2 and 3 years old. The material was processed by the classical histological methods. Pathomorphological study of black back herring’s organs in different years showed that the studied fish species experienced high stress. There has been found a wide range of pathologies which could be caused by a chronic ingestion of pollutants from the environment. It has been stated that the organs through which pollutants enter were most affected (gills, liver, kidneys). The main manifestations 
 of a pathological process were microcirculatory disorders, edema, necrosis, inflammation, connective tissue over-growth, epithelial hyperplasia. All the detected pathological changes in fish organs arose due to the modern environment, which is explained by the disturbances resulting from significant changes in aquatic and terrestrial ecosystems