Histopatologia de branquias e teste de micronúcleos em Astyanax jacuhiensis(Cope, 1894) (Teleostei, Characidae) na avalia??o dos efeitos causados pela exposi??o aguda ao alumínio

摘要

http://dx.doi.org/10.5007/2175-7925.2016v29n1p75 The contamination of aquatic environments by aluminum (Al) is usually caused by several anthropogenic activities. Diverse morphological, physiological and biochemical alterations in aquatic organisms have been attributed to exposure to Al. In this context, the aim of this study was to investigate the effects of acute exposure to different concentrations of Al on the histology of gills and frequency of micronucleus (MN) and nuclear abnormalities (NA) in erythrocytes of the fish Astyanax jacuhiensis . Fish were exposed to sublethal concentrations of 0.3 mg/L and 30 mg/L of aluminum at neutral pH for 72 h. A control group was kept in filtrated water. The alterations in the gills were characterized by epithelial hyperplasia and hypertrophy, lamellar fusion, edema, epithelial lifting, aneurism and necrosis. A significant increase (p&0.05) in the frequency of abnormal lamellae was observed in groups exposed to both concentrations of Al in comparison with the control group. On the other hand, no statistical differences were observed in the frequencies of MN and NA. Although no evidence of genotoxicity was observed, the results found in the gill morphological analysis suggest that Al was toxic to the fish at both concentrations tested under neutral pH.