Evaluation of micronucleus test's sensitivity in freshwater fish species.

Abstract

Nile tilapia (Oreochromis niloticus), Butterfish (Poronotus triacanthus) and Red-tailed tinfoil barb (Puntius altus), three fish species inhabiting in Southeast Asia freshwater ecosystems were evaluated for their use as pollution biomarkers using the micronucleus (MN) and nuclear abnormalities (NA) tests in erythrocytes. NA shapes were scored into blebbed nuclei (BL), lobed nuclei (LB), notched nuclei (NT) and binuclei (BN). Fish were exposed to lead (Pb), copper (Cu) and cadmium (Cd) for the period of 24, 48, 72 and 96 h. It was observed that, fish species showed significant sensitivity to the different heavy metals treatment. In general, the highest value of both MN and NA cells were significantly increased in the exposure to Pb followed by Cu and Cd. On the other hand, Nile tilapia was the most sensitive to the three heavy metals exposure. The frequencies of each NA shape were found in the all fish species and in the all treatments as following NT>LB>BN>BL. Results of MN and NA revealed the highest number after 48 h treatment in all cases and decreased within the longer time exposure. Our results demonstrated the suitability of Nile tilapia for genotoxicity of pollution biomarkers using the micronucleus and nuclear abnormalities test. (Published