Evaluation of genotoxicity using the micronucleus assay and nuclear abnormalities in the tropical sea fish Bathygobius soporator (Valenciennes, 1837) (Teleostei, Gobiidae)

Abstract

The micronucleus and nuclear abnormalities assays have been used increasingly to evaluate genotoxicity of many compounds in polluted aquatic ecossystems. The aim of this study is to verify the efficiency of the micronucleus assay and nuclear abnormality assay in field and laboratory work, when using erythrocytes of the tropical marine fish Bathygobius soporator as genotoxicity biomarkers. Gill peripheral blood samples were obtained from specimens of Bathygobius soporator. In order to investigate the frequencies of micronuclei and to assess the sensitivity of species, the results were compared with samples taken at the reference site and maintained in the laboratory, and fish treated with cyclophosphamide. The micronucleus assay was efficient in demonstrating field pollution and reproducing results in the labotatory. There were significant higher frequencies of micronuclei in two sites subject to discharge of urban and industrial effluents. The nuclear abnormality assay did not appear to be an efficient tool for genotoxicity evaluation when compared with field samples taken at a reference site in laboratory, with a positive control.

Keywords: micronucleus assay; Bathygobius soporator; frillfin goby; genotoxicity; nuclear abnormality assay.

Figure 1

Precipitation during four months of 2005 and mean frequency of micronucleated erythrocytes and nuclear abnormalities in B. soporator at three sites in and, Salvador-Bahia, Brazil. NC: negative control; NP: positive control; Prec. mm/months: precipitation mm/months. MN: micronucleus; NA: nuclear abnormalities.