It has been claimed that bisphenol A (BPA) induces some reproductive potential disorders in the freshwater gastropods worldwide. The adult fecundity and egg hatchability as well as histological effects and embryonic deformities on the exotic freshwater snail Helisoma duryi have been studied to explore the superfeminization phenomena. The results of the 96h.LC50 of BPA for H. duryi was 4.06, and the histological examination for the hermaphrodite gland which was exposed to sub-lethal concentration showed considerable modification and changes in the semineferous
tubules, number of eggs, spermatogenesis and the thickness of surrounding connective tissues. The results highlight the importance of obtaining basic knowledge of information on sub-lethal damage through the life-history of potential test species after exposure to test protocols.