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:

1. Coral Coloration: Fluorescence: Part 1
2. Coral Coloration, Part 2: Fluorescence: Pigments 510 – 565 and Notes on Green Fluorescent Proteins
3. Coral Coloration, Part 3: Pigments Responsible for
4. Coral Coloration, Part 4: Red Fluorescent Pigments, a Preliminary Report of Effects of Various Environmental Factors and Color Mixing
5. Coral Coloration, Part 5: Non-fluorescent Chromoproteins (CP-480 to CP-562)
6. Coral Coloration, Part 6: Non-fluorescent Chromoproteins (CP-568 – CP-610) And A Newly Discovered Colorant
7. Coral Coloration – Part 7: Coral Reflectance, Chromoproteins and Environmental Factors Affecting Non-fluorescent Pigmentation
8. Coral Coloration, Part 8: Blue and Green Coral Fluorescence: Environmental Factors Affecting Fluorescent Pigmentation
9. Coral Coloration, Part 9: Tridacna and Other Photosynthetic Clam Coloration, With Observations on Possible Functions