Effects of soluble sulfide on zebrafish (Danio rerio) embryonic development.

Zebrafish embryos were used to investigate the developmental effects of sulfide. Mortality, teratogenic effects, and developmental parameters of early developmental embryos were recorded. The biodistribution of sulfide in developing zebrafish embryos and larvae were measured through fluorescence imaging. The influences of sulfide on the cardiac function and development velocity of zebrafish embryos were dependent on sulfide concentration. Heart rate and development velocity increased with exposure to lower sulfide concentrations, which may be attributed to the cardioprotective properties of H2S. Meanwhile, heart rate and development velocity decreased, whereas pericardial edema, yolk sac edema, and trunk abnormalities occurred with exposure to higher sulfide concentrations. Sulfide accumulated in the blastoderm of early developmental embryos and was then transported to the yolk sac and yolk extension with the embryonic development. Finally, sulfide was transferred from the yolk to the eyes of zebrafish larvae. The details of mechanism of sulfide toxicity require further research.