**Abstract**

Anthropogenic pollution of the freshwater basins is a serious environmental problem. This has necessitated the search for different approaches to the detection of different pollutants in water bodies. Many authors point out that the hematological parameters of freshwater fish are sensitive to the action of various pollutants in freshwater basins. This chapter summarizes the results of studies on the effects of current water pollutants (heavy metals, organic matter, etc.) on erythrocytes and hemoglobin in fish. An analysis of the possibility of the use of erythrocyte damage and the change in the hemoglobin content of the tested animals for the purposes of ecological biomonitoring of freshwater pollution will be made.

**Keywords:** anemia, biomonitoring, ecotoxicology, erythrocyte abnormalities, teleost, water pollution
