TOXICITY OF COPPER SULPHATE AND BEHAVIORAL LOCOMOTOR RESPONSE OF TILAPIA (Oreochromis Niloticus) AND CATFISH (Clarias Gariepinus) SPECIES

Acute toxicity of copper sulphate (CuSO4.5H2O) to tilapia (Oreochromis niloticus) and catfish (Clarias gariepinus) species was investigated using toxicity index of 96 hours LC50 and the quantal response determined by the statistical probit analysis method. In response to the lethality of the copper toxicant, behavioral anomalies (locomotor response) of the exposed fish species were studied as indication of toxic effects of the heavy metal. Fish species shows different mortality responses to the varying concentrations of copper studied (50, 60, 70, 80, 100, and 120 mg/l) due to toxicity. Copper was significantly (no overlap in 95% C.L of 96 hrs LC50 values) more toxic to Oreochromis niloticus than the catfish. 96 hrs LC50 values for Oreochromis niloticus and Clarias gariepinus were revealed to be 58.837 and 70.135 mg/l, respectively. Behavioral changes, mostly locomotor responses (avoidance) were observed among the test animals on exposure to the different concentrations of copper sulphate. There is need to control the use of copper because of its observed toxicity and fish avoidance test shows to be an important predictive and sensitive biomarker in aquatic monitoring and pollution management.