Toxic effect of Zanthoxylum rhetsa seed extracts on stinging catfish, Heteropneustes fossilis (Bloch, 1794)

Abstract

Ninety six hours of toxicity test was conducted to observe the lethal concentration (LC50) value of Zanthoxylum rhetsa seed extracts on a stinging catfish, Heteropneustes fossilis. The fishes were exposed to seven different concentrations of the extract (25 mg l-1, 35 mg l-1, 45 mg l-1, 55 mg l-1, 65 mg l -1, 75 mg l -1and 85 mg l -1) for toxicity test and one remained as control. The LC50 value of Z. rhetsa in H. fossilis was found to be 70.1 mg l-1 for 96 hours exposure periods. Analysis of variance for the effect of the extract on the percentage mortality of fish showed a significant relation between both the factors (p