We’ve posted stunning videos of coral fluorescence and were awestruck when we saw this video of fluorescing nudibranchs and scorpionfish. Corals are thought they glow to attract symbiotic algae or to protect the coral from UV light. But why do animals fluoresce? Most experts feel creatures, like the nudibranch and scorpionfish in this video, use fluorescence as a way to camoflage itself, to warn others or as a sexual signal. Fluoro-frogfish photo above by Jeffrey Honda Photography.