Piscicidal Effects of Extracts of Karenja Plant Pongamia pinnata (L.) Pierre and Vat plant Clerodendrum viscosum (Vent.) on singhi Fish Heteropneustes Fossilis (Bloch)

Abstract

The piscicidal properties of the seed, leaf and bark of the indigenous plants, karenja Pongamia pinnata (L.) Pierre and vat Clerodendrum viscosum (Vent.) were studied on the predatory fish Singhi, Heteropneustes fossilis (Bloch) under laboratory conditions. Distilled water, 50% ethyl alcohol and absolute ethyl alcohol extracts of the plant parts of the plants were tested in this experiment. The altered behaviour due to the effects of the extracts was noted, initially hyperactivity, losing stamina and in the later period, after a few hours, the affected fishes becoming sluggish and inactive. Mortality data varied depending upon the toxicity of the plant parts, extracts and concentrations. On the basis of concentrations, the relative toxicity of the piscicides on H. fossilis for P. pinnata was found to be in the order of seed > bark > leaf and for C. viscosum, seed > leaf > bark. The toxicity of seed and leaf extracts of C. viscosum was greater than P. pinnata but opposite for bark extract for the fish. On the basis of LC₅₀ values the toxicity of both the plant parts were similar as to seed > bark > leaf.

The Chittagong Univ. J. B. Sci.,Vol. 7(1 &2):65-78 , 2012.