Effect of Tributyltin on the Sex Ratio in Guppy (Poecilia reticulata)

Abstract

In this study, the effect of tributyltin (TBT) on the sex ratio in guppy (Poecilia reticulata) during thelabile period covering both embryonic and post hatching periods was investigated. The gravidfemales was fed an artificial diet containing TBT chloride at an environmental levels of 25, 50 and150ng/g feed from 16th day after the first parturition until next parturition. The newly hatched larvae from untreated females were also fed by the same diet for 11 days. TBT caused various abnormalities like body shape and fin deformations in gravid females and no parturition was seen. Themale ratio significantly increased to 70.74, 87.50 and 87.18 % in the experimental groups of guppylarvae fed by 25, 50 and 150ng TBT/g diet, respectively. Survival and growth of the larvae werenegatively affected by TBT treatment. These results clearly showed the masculanization of guppyexposed to TBT for the first time.