Ichthyotoxic propensities of some Indian marine green algae (Chlorophytes)

Abstract

Twenty three extracts of chlorophytes have been assayed for ichthyotoxicity against the common mosquito fish <i>Gambusia affinis</i>. The extracts generally have exhibited a wide range of effects. Of the twenty three species of chlorophytes, 35% exhibited ichthyotoxic properties causing mortality in fish and the remaining 65% were found to be nontoxic. Further, <i>Bryopsis plumosa</i> was highly toxic, <i>Caulerpa cupressoides, Bryopsis</i> sp., and <i>Halimeda gracilis</i> were moderately toxic and <i>Caulerpa fergusonii, C.racemosa, C.peltata</i> and <i>C.taxifolia</i> were found less toxic. These results suggest that some marine chlorophytes posses protective chemical defense mechanism against herbivorous fishes.