Glowing bacteria on deep-sea fish shed light on evolution, ‘third type’ of symbiosis

You may recognize the anglerfish from its dramatic appearance in the hit animated film Finding Nemo, as it was very nearly the demise of clownfish Marlin and blue-tang fish Dory. It lives most of its life in total darkness more than 1,000 meters below the ocean surface. Female anglerfish sport a glowing lure on top of their foreheads, basically a pole with a light bulb on its end, where bioluminescent bacteria live. The light-emitting lure attracts both prey and potential mates to the fish.