Concentration-dependent effects of nonylphenol on testis structure in adult platyfish Xiphophorus maculatus

Nonylphenol has been found to exert estrogenic effects in fish and may affe ct the fertility of male fish. The objective of this study was to use the p latyfish, Xiphophorus maculatus, as a model to evaluate the concentration-d ependent effects of nonylphenol on the testicular structure. A tendency of a concentration-dependent decrease in the gonadosomatic index was observed after 28 days of treatment with nonylphenol. Histological examination revea led marked effects of nonylphenol on the testis structure. The effects were more pronounced at the higher concentrations of nonylphenol. This study st rongly suggests that exposure to nonylphenol can result in decreased fertil ity in X. maculatus males. (C) 2000 Published by Elsevier Science Ltd.