Medaka Toxicity Testing
We are using medaka as a model for assessment of endocrine disruption because of the following advantages:
- Medaka is a small fish, easy to breed and maintain in large numbers under laboratory conditions, has high growth rates and matures from fry to breeding adults in a relatively short period (8-10 weeks).
- Medaka is a gonochoristic fish species and has the XY-XX genetic sex determination system, while zebrefish being the most studied model fish species is hermaphroditic until the juvenile stage and all individuals develop ovary-like gonad. This feature allows us to evaluate sex specific effects of chemicals of emerging concerns.
- Medaka embryos incubated in surface water showed characteristic deformities. Here is one of them: the development of embryonic body was disrupted, however the heart is beating (Left, 8 days post fertilization). Right: medaka in control group, 8 dpf