Biofluorescent

Biofluorescence is the emission of light by living organisms after absorption of light from an external source, typically blue or ultraviolet light, followed by re-emission at a longer wavelength such as green, yellow, or red. It differs from bioluminescence, which generates light through chemical reactions within the organism; biofluorescence requires external illumination to be visible.

In nature, biofluorescence is especially common in marine organisms. Corals, certain fishes, sharks, and other reef dwellers exhibit vivid fluorescence patterns when illuminated by blue light. The effect is produced by fluorescent proteins or pigment molecules, including variants related to the green fluorescent protein family, or by pigments that act as fluorophores. The emitted light depends on the molecule and can range from green to red.

Functions are still studied; proposed roles include enhanced intra-specific communication, signaling to mates, amplification of existing patterns, camouflage through matching ambient light, or prey detection; the overall ecological significance varies by species and environment.

Researchers study biofluorescence using specialized lighting and imaging; in marine biology, blue excitation light is used to reveal fluorescence patterns that are not visible under white light. Biofluorescence is distinct from bioluminescence, which is self-generated light.