We’re not talking just about corals, which every reefkeeper already knows about. Fish, cephalopods, crustaceans, tunicates, sponges, cowries, nudibranchs, flatworms, algae, and all forms of sea life emit other-worldly biofluorescence.
With the aid of special photography equipment (blue light + barrier filters), we can view these animals like never before. All the neon colors you see in this night dive video by Jeff Honda are 100% real. The ocean is truly an amazing, alien world!
What is fluorescence?
Adam Blundell, M.S. writes about ‘The Seen and Unseen World of Coral Fluorescence‘ in Advanced Aquarist’s June, 2005 issue:
Fluorescence is a process whereby a matter of energy is absorbed by a substance, and then released by that substance with less energy. In this case a light source of high energy (lets say blue light) is absorbed by a substance (a coral) and then released with less energy (i.e. green light or red light).
Dana Riddle writes what may be the most comprehensive series of articles on coral coloration & fluorescence: