A Reproductive Toxicology Study of Phenanthrene in Medaka (Oryzias latipes)

Abstract Environmental contaminants, such as polycy-clic aromatic hydrocarbons (PAHs), can disrupt the endo-crine system and affect reproductive function of humans and wildlife. In this study, we exposed Japanese medaka (Oryzias latipes) to water-borne or food-spiked phenan-threne, an ubiquitous PAH, and investigated the chronic effects of the chemical on medaka reproduction. The results showed that phenanthrene significantly prolonged the time to hatch for embryos. Other parameters such as fecundity and fertility, organ-somatic ratios, hepatic vitel-logenin production, and the histology of testes and ovaries were not different between the control and phenanthrene-treated groups. This suggests that the time to hatch in embryos might be a more sensitive biomarker for envi-ronmental contaminants. Environmental contaminants could disrupt the endocrine system and affect the reproductive function of humans an