What is fluorescence in corals and other reef animals?
CM: From the physics point of view, fluorescence is the process by which light of one wavelength (color) is absorbed in a substance and transformed into another color. On the biology side, fluorescence comes from a few sources—the intense greens, yellows, and oranges in your corals and anemones come from fluorescent proteins in the host tissue; a deep red fluorescence originates from chlorophyll in algae, including the symbiotic algae in the invert tissues, and algae coating live rock and your tank walls. You get an orange fluorescence from phycoerythrin, a photosynthetic accessory pigment found in red algae and cyanobacteria. We have found fluorescence in many other reef animals, including fish, shrimp, crabs, mantis shrimp (more on them below), bristleworms, and more. In many cases we have no idea what is doing the fluorescing. BZN: While many aquarists are familiar with the effects produced by actinic lighting, what are the best ways to stimulate and observe fluorescing proteins in
