Ecology, Environment and Conservation Paper

TOXICITY EFFECT OF SOME SELECTED CHEMICALS ON FISH TILAPIA MOSSAMBICLIS

M.Y.Yazdandoost

Abstract

The active metabolic rate of fish is affected by a variety of environmental contaminants.These effects may be direct or indirect. Of the multitude of organismal responses that could be observed as endpoints in toxicity tests, the one most frequently used is survivorship. In ecotoxicology, survivorship is usually expressed as lethal concentration for 50 per cent individuals (LC50). In the present study.