Histopathological and cytogenetic effects of water pollution in some freshwater fish of Egypt

Abstract

Fish are adequate tool for the establishment of relationships between exposure to environmental pollution and genetic damage. The various histopathologic alterations detected in the liver, kidney and spleen of Oreochromis niloticus, Sarotherodon galilaeus and Tilapia zilli from the more polluted Bahr Shbin and the less polluted Gezirat El Dahab area were investigated. The liver showed to be the organ most affected by the type of contaminant of which the fish were subjected. By using the micronucleus (MN) test, significant values of micronuclei number were detected at Bahr Shbin area. By using the comet assay, the frequency of cells exceeding 50% tail DNA was higher at Bahr Shbin area. In conclusion, the histological changes observed in the liver, kidney and spleen of the three tested species of tilapia in the present study indicates that the fish were responding to the direct effect of the contaminants and reflect the biological impact of complex mixture of pollutant present in this area. The Nile tilapia fish 0. niloticus was show to be appropriate for different in situ tests and environmental monitoring.