Discipline: Animal Science
Industrialization has caused the production, utilization and release of various anthropogenic substances in the environment. A group of these compounds, the xenoestrogens, has been implicated in various reproductive impairments in wildlife populations. Most researches on xenoestrogens have been based on waterborne exposure of fish. In a partial life cycle test, the impact of a diet contaminated with the xenoestrogen 17a-ethinylestradiol (EE2) on reproductive endpoints such as fecundity, fertilization success, vitellogenin (vtg) induction and testicular morphology of sexually mature male zebrafish was evaluated using a semi-static set-up. Vtg concentrations were measured in fish whole-body homogenate samples using enzyme-linked immunosorbent assay. Results revealed that exposure to 0.02 mg/g EE2 reduced fecundity without altering fertilization success. Vtg induction was also noted in exposed males. Furthermore, exposure decreased luminal space in the seminiferous lobules of the exposed gonads. Whether these effects translate into a reduced reproductive fitness of exposed males in the wild could be a subject of future research.