Abstract
A four-day static renewal acute toxicity test was performed to determine the LC50 value of aqueous extract of Euphorbia tirucalli latex for the freshwater fish, Heteropneustes fossilis. The LC50 values, their upper and lower confidence limits and slope functions were calculated. The LC50 values for aqueous extract of E. tirucalli latex at various exposure periods are 3.450 mu l/L for 24 h, 2.516 mu l/L for 48 h, 1.623 mu l/L for 72 h and 1.315 mu l/L for 96 h. The toxicity of aqueous extract of E. tirucalli latex exhibits a positive correlation between fish mortality and exposure periods. It is concluded that latex of E. tirucalli has higher piscicidal activity as compared with other synthetic pesticides, organophosphates and pyrethroids for the fish H. fossilis. Hence, adequate precautions must be exercised when E. tirucalli latex is being used near fish-inhabiting water reservoirs. (C) 2010 Elsevier Inc. All rights reserved.