Turns out that some fish have a secret code- of colors! We now know that over 180 species of fish exhibit biofluorescence: they absorb blue light, transform it, and emit a different colored light. In fact, fluorescent proteins that were originally derived from jellyfish are now commonly used in biomedical research applications. Researchers can track these fluorescent proteins to determine gene expression, which is pretty cool.
But while scientists have known about biofluorescence in jellyfish and corals for years, it’s only recently that biofluorescence in eels, fish, and sharks has been observed. It hasn’t been detected before, because like a true secret code, not everyone can ‘read’ it. Many fish have yellow filters in their eyes, allowing them to see this secret code- but the colors are undetectable to the human eye. The discovery was made by accident- underwater photography using blue lights revealed an eel that glowed green when the pictures were developed!
So what’s the purpose of this secret code? Well, they’re not quite sure yet. But it will be interesting to see what scientists can learn about these fish, both for a better understanding of the animals as well as a determination of possible research applications. Another reason why science kicks ass- unlocking secret codes is all in a day’s work!