Determination of histologic and genotoxic effects of sublethal dose of chlorpyrifos-ethyl on carp fingerlings (Cyprinus carpio L., 1758)

In this study; the carp (Cyprinus carpio L.) fingerlings were exposed to sublethal dose of 16 µg/L (1/10 of 96 h LC50 value) of organophosphorus insecticide chlorpyrifos-ethyl for 24, 48, 96 hours and 7 days. At the end of the experiment different frequencies of nucleus abnormalities and micronuclei were determined in peripheral erythrocytes. Although the differences between control groups and the groups exposed to chlorpyrifos-ethyl were not found statistically significant (P>0.05) in terms of nuclear normalities, the differences between the control group and the groups exposed to chlorpyrifos-ethyl were found statistically significant in terms of micronucleus test (P<0.05); as a result the pesticide was determined as genotoxically effective. Cloudy swelling, hydropic degeneration, hyperemia in hepatopancreas tissues, and hyperemia, telangiactasis, hyperplasia, branchitis, oedema, chloride cell hyperplasia, fusion in gill tissues, and hemorrage, hyperemia in kidney tissues, vacuolisation in bowman capsule, melanization in kidney tissues and tubules, swollen glomerulus, hydrophic degeneration in tubules are the major histopathologic findings determined in carp fingerlings exposed to chlorpyrifos-ethyl. No histopathological findings were found in control groups. Longer exposure to chlorpyrifos-ethyl did not reveal of more histopathological findings, in more fish, and the severity of the findings.In conclusion it is determined that exposure to chlorpyrifos-ethyl even in sublethal concentration caused genotoxic effects and tissue damages in carp fingerlings.