Micronucleus test in Centropomus undecimalis (BLOCH, 1972) for the assessment of the water quality of two Brazilian estuaries

Abstract

Fish species of the Centropomus genus are important food resources in Brazil. The species of this group are predators that feed on small fish and benthic invertebrates, and are therefore vulnerable to bioconcentration and the biomagnification of contaminants. As estuaries are continuously impacted by urbanization, the aim of the present study was to evaluate the quality of two brackish environments located in the Ilha do Maranhão, Brazil, by applying the Micronucleus Test with Centropomus undecimalis. Genotoxic lesions were detected in the erythrocytes using this test. Blood samples were collected through punctures of the gills to produce the blood extensions. The smear was stained with modified Rosenfield dye and 2,000 erythrocytes per fish were analyzed. The micronucleus values differed significantly between the two locations in the rainy season, showing that Centropomus undecimalis is more vulnerable to contamination in the Bacanga River Basin. In view of the results, the Micronucleus Test proved to be an effective tool for the evaluation of the environmental quality of areas, and the data generated in the study can contribute to conservation programs by local management authorities, as the biomarker used allows the evaluation of the health of the environment through two organisms.