If you’re a millennial, there’s a good chance you’ve read The Rainbow Fish, a delightful children’s book where the titular character is illustrated with shiny foil that seems to glitter with all ...

You can see right through this little aquarium fish from Thailand: Its skin is almost completely transparent. But when the light hits it just right, its body flickers with shimmering rainbow colors.

Monica Cull is a Digital Editor/Writer for Discover Magazine who writes and edits articles focusing on animal sciences, ancient humans, national parks, and health trends. View Full Profile. Some ...