Behavioral intoxication of Channa marulius and Wallago attu during acute exposure of cadmium and copper

Aquatic contamination by heavy metals is a worldwide environmental problem. this contamination is due to different anthropogenic activities of human. different metals have the tendency to induce harmful effect on living organisms. in order to evaluate the acute response of cadmium and copper alterations in the behaviour of freshwater fish,channa (c.) marulius and wallago (w.) attu,the static bioassay tests were carried out. the lc50 values of cadmium and copper were determined as 75.70±0.91; 32.96±0.36 and 1.07±0.01; 0.60±0.02 mg l-1 for c. marulius and w. attu,respectively. during the acute exposure of both metals,the fish showed some abnormal activities like erratic swimming,equilibrium loss and enhanced surfacing behaviour. the metals concentrations showed direct relationship with fish hyperactivity and convulsions rate. the cadmium and copper exposed test mediums showed directly maximum relationship with somersaulting activity (r2=0.838; 0.861) for c. marulius while the same for w. attu was maximum with hyperactivity (r2=0.797; 0.882). these indications were more pronounced for both fishspecies in the copper than cadmium exposed test mediums. the fish kept in the medium without metal exposure showed normal behaviour and activity.