Bioluminiscens

Bioluminiscens, or bioluminescence, is the production and emission of light by living organisms. In most systems the light results from a chemical reaction in which a substrate called luciferin is oxidized by an enzyme called luciferase in the presence of molecular oxygen. The reaction releases photons, producing visible light. Some bacteria generate light through a different luciferase system, often in symbiosis with marine animals, while in many organisms the light originates in specialized tissues called photophores or photocytes.

The color and intensity of bioluminescent emission vary among species, but blue and green light are common in marine environments because these wavelengths travel farther in seawater. Light production can be continuous or pulsed, depending on ecological needs and signaling purposes. Bioluminescence serves a range of functions, including camouflage (counter-illumination), attraction of prey or mates, communication, and defense against predators.

Bioluminescent organisms occur in terrestrial and marine habitats. Terrestrial examples include fireflies and glow-worms, which use light mainly for mating signals. In the ocean, dinoflagellates, certain jellyfish, scallops, octopuses, and deep-sea fishes rely on light-producing organs to navigate, hunt, or communicate in dim environments. Some species harbor symbiotic luminous bacteria in their light organs.

In science and biotechnology, luciferase enzymes and their substrates are widely used as bioluminescent reporters in molecular biology, enabling sensitive imaging of gene expression, cellular processes, and diagnostic assays. The study of bioluminiscens spans biology, ecology, evolution, and applied science.