| Popis: |
A static bioassay method to determine the acute toxicity of the herbicide propanil to Oreochromis niloticus was investigated under Laboratory conditions for 96 hours exposure period. Concentrations of propanil used include: 0.0096ml/l, 0.0103ml/l, 0.011ml/l and 0.012ml/l respectively. The lethal concentration (LC50) value of propanil on fingerlings of Oreochromis niloticus was 0.0097ml/l for 96 hours of exposure. The regression equation for probit kill from propanil was found to be Y = 29.84 + 12.33* log conc. (r2 0.9951, Y = Probit kill). Fish showed various abnormal behaviours upon exposure to propanil. Immediate reaction was erratic swimming and tendency to jump out of the test bowl. Others include: restlessness, un-coordinated movement, vertical swimming, air gulping, equilibrium loss, a period of quiescence and eventually death. |
