Depuration technique of xenobiotics with reference to accumulation and elimination of paraquat dichloride in Clarias gariepinus

Paraquat dichloride is a highly toxic herbicide which is still used in many developing countries. African cat fish (Clarias gariepinus) is a commercially important species in many countries and was selected assess accumulation and elimination of paraquat dichloride in its tissues. Groups of ten fish with equal lengths and weights were exposed to varying concentrations of Paraquat dichloride for 28 days. After the exposure, the fish were transferred to uncontaminated water. Two fish were sampled for pesticide residue at the end of exposure period (28days) and 1, 7 and 14 days post exposure. In pesticide treated fish, the accumulation of paraquat increased with increases in the concentration of the toxicant and varied significantly between the treatments (p < 0.05). The herbicide depurated gradually with cessation of exposure and no pesticide was observed after 14 days. Xenobiotics could be eliminated from aquatic organisms especially fishes and could be put into practice in areas at risk of pollutants. This novel approach can reduce the risks of biomagnification of poisons in sea food.