You May Have Already Eaten the First Known Fluorescent Vertebrate

Your hovercraft may not be full of them, but there's a good chance that you've already eaten one:

The Japanese eel, Anguilla japonica, a freshwater species, is known as unagi in Japan, where it's an extremely common ingredient in the cuisine. It's grilled, served in sushi, and given many more preparations. The chemists, who primarily study food, were investigating how light interacts with the oily flesh of the eel, and noticed something odd: when hit with a blue light, the eel positively glows.
In a paper in the current issue of Nature the researchers describe how they isolated and identified the specific protein responsible for the fluorescence. After examining it, they noticed that it's very different from the proteins that cause fluorescence in other lifeforms. It shines brightly even with low oxygen levels, for one thing, and it also requires a substance called bilirubin, which is found in bile.

More