In the pitch-black environment of the deep sea, light is a precious thing. In fact, making light is essential for the survival of many deep-sea animals. At least nine major groups of deep-sea animals, including jellies, corals, brittle stars, squids, and fish, use the same light-emitting chemical, coelenterazine, to power their displays. Surprisingly, many of these animals can’t actually produce coelenterazine, but must get it by eating other glowing animals.
Click here for original story, Comb jellies make their own glowing compounds instead of getting them from food
Source: Phys.org