Adaptive and pathological responses of cyprinidae liver towards habitat in the Volga delta

Human impact on ecosystems makes it imperative to monitor populations of different fish species from various perspectives. The consequence of environmental impact on living organisms is the reactions of organs and organ systems, which find their reflection in pathological changes in the fish body particularly. Reactions in the fish body are the result of the combined influence of environmental factors and natural physiological processes associated with feeding, migrations, generative cycles, etc. The changes in the structure of organs detected in fish make it possible to assess the influence of the environment on fish. The research was carried out in the Volga delta, the Bereket (upper delta) and the Kostyl (lower delta) rivers. Reservoirs for research were chosen in such a way that they were subject to anthropogenic influence to varying degrees. Unfavorable living environment represented by pollutants increase the functional load on the liver. The research has shown an increase in the liver index in fish from reservoirs with a higher level of anthropogenic load. Metabolic functioning of liver cells is considered as an important protective mechanism against toxicants, while the associated transformations are somehow connected with detoxification. Histological preparations were made according to standard methods.