Some fish glow red

Icthyologists know that countless fish have lights of one kind or another, and some fluoresce all over in green or blue. A fish that glows red all over, though, is a new phenomenon. It's not that the species Enneapterygius pusillus was undiscovered, but no one knew, until a chance observation in the wild, that it could light its body up like a neon sign. Researchers began to look at other fish through goggles or filters allowing them to see red light deep underwater (where red light does not penetrate) and found many other examples of fish whose bodies, or selected areas, glow red. To put it another way, the red glow from the fish is always visible, but humans that deep normally can't see it and so didn't know this phenomenon was taking place. Now discoverer Nico Michiels can announce, "red fluorescence is widespread among marine fish."