Effects of Kepone® on the sheepshead minnow in an entire life-cycle toxicity test

A life-cycle toxicity test with the estuarine sheepshead minnow (Cyprinodon variegatus) and the insecticide Kepone^® (chlordecone) in seawater showed that the maximum acceptable toxicant concentration (MATC) lies between 0.074 and 0.12 ?g Kepone/L, based on reduced standard length of progeny at 0.12?g/L and higher concentrations. The application factor range (MATC/96-hr LC50) for sheepshead minnows exposed continuously to Kepone is from 0.001 to 0.002. Other adverse effects of Kepone exposure were: External signs of poisoning in fish exposed to concentrations =0.074?g/L, fatty degeneration of the liver and histological evidence of vertebral damage in some fish exposed to 0.78?g/L, reduced growth of parental fish at 0.39 and 0.78?g/L, reduced fecundity and fertility of eggs at 0.78?g/L, and reduced survival of embryos produced by fish exposed to 0.78?g/L. Average bioconcentration factors (concentration in tissue ÷ average measured concentration in water) ranged from 2,600 for 21-day-old juveniles to 7,600 for adult males.