Acute Toxicity of Chlorpyriphos 50% + Cypermethrin 5% EC to the Guppy, Poecilia reticulata (Peters, 1859)

摘要

The present study was aimed to investigate the acute toxicity of Chlorpyriphos 50% +Cypermethrin5% EC to the juveniles, males, females and mixed population of a freshwater fish, Poecilia reticulata (Peters).The experimental water of hardness 560±5 mg/l and pH 7.4±0.3 were used in bioassay tests. The LC50 valuesand the 95 percent confidence limits were calculated statistically at different concentrations and time intervals(24, 48, 72 and 96 hrs) to juveniles, males, females and mixed population of Poecilia reticulata by Probitanalysis method. Behavioural changes in the studied fish were also observed carefully after subjected to thevarious concentrations of this pesticide. The order of sensitivity of selected pesticide to different specimensof Poecilia reticulata was recorded as: females < mixed population