Changes in hematological parameters of Cichlasoma dimerus (Teleostei, Perciformes) exposed to sublethal concentrations of 4-tert-octylphenol.

Stress response involves various physiological changes, including alteration in hematological parameters closely related to the response of fish to the environment. 4-tert-octylphenol (OP) is one of the worldwide-used surfactants and can pollute the aquatic environment, both marine and freshwater. Previous studies have already shown estrogenic effects of this compound in various wildlife species, e.g., it can disrupt the reproductive system of males organisms including fish. The purpose of this study was to evaluate the effects caused by sublethal concentrations of OP on hematological parameters as biomarkers to assess environmental stress. Adult males and females of Cichlasoma dimerus were exposed to waterborne OP during 60 days under semistatic conditions. Experimental groups consisted of control (ethanol 0.005 %), OP 150, and OP 300 μg/L. OP caused hemodynamic stress in C. dimerus, which lead to normochromic and normocytic anemia, as well as erythrocytic pathologies such as a significant increase in erythroblasts and amitotic erythrocytes. All of the studied parameters can be used as biomarkers for the presence of xenobiotics in water.