Acute toxicities of diethyl ether and ethanol extracted <i>Nerium indicum</i> leaf to the fish, <i>Heteropneustes fossilis</i>

Abstract

A four-day static renewal acute toxicity test was performed to determine the LC₅₀ value of ethanol and diethyl ether extracted Nerium indicum leaf for the freshwater fish, Heteropneustes fossilis. The LC₅₀ values, their upper and lower confidence limits and slope functions were calculated. The LC₅₀ values for ethanol extracted Nerium indicum leaf at various exposure periods are 155 mg/L for 24 h; 115 mg/L for 48 h; 87.5 mg/L for 72 h; and 60 mg/L for 96 h. The LC₅₀ values for diethyl ether extracted Nerium indicum leaf at various exposure periods are 38 mg/L for 24 h; 27 mg/L for 48 h; 20 mg/L for 72 h; and 14 mg/L for 96 h. The toxicity of Nerium indicum leaf extracts (both ethanol and diethyl ether extracted) exhibits a positive correlation between fish mortality and exposure periods (mortality of fish at a given concentration is increased with increased duration of exposure).

Key words: Toxicity, Fish, Nerium, LC₅₀