Bioluminescence is the production and emission of light by a living organism. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms and terrestrial invertebrates. Some Symbiotic organisms carried within larger organisms produce light.
Bioluminescence is a form of luminescence, or "cold light" emission by living organisms; less than 20% of the light generates thermal radiation. It should not be confused with iridescence, structural coloration, phosphorescence.
Bioluminescence is a form of chemiluminescence where light energy is released by a chemical reaction. Fireflies, anglerfish, and other creatures produce the chemicals luciferin (a pigment) and luciferase (an enzyme). The luciferin reacts with oxygen to create light. The luciferase acts as a catalyst to speed up the reaction, which is sometimes mediated by cofactors such as calcium ions or ATP. The chemical reaction can occur either inside or outside the cell. In bacteria, the expression of genes related to bioluminescence is controlled by an operon called the Lux operon.
Bioluminescence occurs widely among some groups of animals, especially in the open sea; in some fungi and bacteria; and in various terrestrial invertebrates including insects. Many, perhaps most deep-sea animals produce light. Most marine light-emission is in the blue and green light spectrum, the wavelengths that pass furthest through seawater. However, some loose-jawed fish emit red and infrared light, and the genus Tomopteris emits yellow light. Sometimes thousands of square miles of the ocean shine with the light of bioluminescent bacteria in the "Milky seas effect".
Non-marine bioluminescence is less widely distributed. The two best-known forms of land bioluminescence are fireflies and glow worms. Other insects, insect larvae, annelids, arachnids and even species of fungi have been noted to possess bioluminescent abilities. Some forms of bioluminescence are brighter (or exist only) at night, following a circadian rhythm.
Uses in nature 
Bioluminescence has several functions in different taxa.
Counterillumination camouflage 
In many animals of the deep sea, including several squid species, bacterial bioluminescence is used for counterillumination camouflage, in which the animal matches the overhead environmental light as seen from below. In these animals, photoreceptors control the illumination to match the brightness of the background. These light organs are usually separate from the tissue containing the bioluminescent bacteria. However, in one species, Euprymna scolopes, the bacteria are an integral component of the animal's light organ.
Bioluminescence is used as a lure to attract prey by several deep sea fish such as the anglerfish. A dangling appendage that extends from the head of the fish attracts small animals to within striking distance of the fish.
The cookiecutter shark uses bioluminescence to camouflage its underside, but a small patch near its pectoral fins remains dark, appearing as a small fish to large predatory fish like tuna and mackerel swimming beneath it. When such fish approach the lure, they are bitten by the shark.
Dinoflagellates may use bioluminescence for defence against predators. They shine when they detect a predator, possibly making the predator itself more vulnerable by attracting the attention of predators from higher trophic levels. A South American giant cockroach, Lucihormetica luckae, uses bioluminescence to mimic the toxic Pyrophorus beetle for defensive purposes.
Attracting mates 
In the marine environment, use of luminescence for mate attraction is well documented only in ostracods, small shrimplike crustaceans. Pheromones may be used for long-distance communication, with bioluminescence used at close range to enable mates to "home in".
Certain squid and small crustaceans use bioluminescent chemical mixtures or bacterial slurries in the same way as many squid use ink. A cloud of luminescent material is expelled, distracting or repelling a potential predator, while the animal escapes to safety.
Communication (quorum sensing) plays a role in the regulation of luminesence in many species of bacteria. Using small extracellularly secreted molecules, they turn on genes for light production only at high cell densities.
While most marine bioluminescence is green to blue, the Black Dragonfish produces a red glow. This adaptation allows the fish to see red-pigmented prey, which are normally invisible in the deep ocean environment where red light has been filtered out by the water column.
Bioluminescent organisms are a target for many areas of research. Luciferase systems are widely used in the field of genetic engineering as reporter genes. Luciferase systems have also been harnessed for biomedical research using bioluminescence imaging. Vibrio symbiosis with numerous marine invertebrates and fish, namely the Hawaiian Bobtail Squid (Euprymna scolopes), are key experimental models for bioluminescence.
The structures of photophores, the light producing organs in bioluminescent organisms, are being investigated by industrial designers. Engineered bioluminescence could perhaps one day be used to reduce the need for street lighting, or for decorative purposes.
- Poisson, Jacques (April 2010). "Raphaël Dubois, from pharmacy to bioluminescence". Rev Hist Pharm (Paris) (in french) (France) 58 (365): 51–6. ISSN 0035-2349. PMID 20533808.
- E. Thomas & Williams Ltd. "Original Types of Miners' Flame Safety Lamps". Welshminerslamps.com. Retrieved 13 March 2013.
- Smiles, Samuel (1862). Lives of the Engineers. Volume III (George and Robert Stephenson). London: John Murray. p. 107. ISBN 0-7153-4281-9. (ISBN refers to the David & Charles reprint of 1968 with an introduction by L. T. C. Rolt)
- Kirkwood, Scott (Spring 2005). "Park Mysteries: Deep Blue". National Parks Magazine (National Parks Conservation Association). pp. 20–21. ISSN 0276-8186. Retrieved 14 June 2010.
- Hastings JW (1983). "Biological diversity, chemical mechanisms, and the evolutionary origins of bioluminescent systems". J. Mol. Evol. 19 (5): 309–21. doi:10.1007/BF02101634. ISSN 1432-1432. PMID 6358519.
- Ross, Alison (27 September 2005). "'Milky seas' detected from space". BBC. Retrieved 13 March 2013.
- Young, RE; Roper, CF. (1976). "Bioluminescent countershading in midwater animals: evidence from living squid". Science 191 (4231): 1046–8. Bibcode:1976Sci...191.1046Y. doi:10.1126/science.1251214. PMID 1251214.
- Tong, D; Rozas, NS; Oakley, TH; Mitchell, J; Colley, NJ; McFall-Ngai, MJ (2009). "Evidence for light perception in a bioluminescent organ". Proceedings of the National Academy of Sciences of the United States of America 106 (24): 9836–41. Bibcode:2009PNAS..106.9836T. doi:10.1073/pnas.0904571106. PMC 2700988. PMID 19509343.
- Young, Richard Edward (October 1983). "Oceanic Bioluminescence: an Overview of General Functions". Bulletin of Marine Science 33 (4): 829–845.
- Martin, R. Aidan. "Biology of Sharks and Rays: Cookiecutter Shark". ReefQuest Centre for Shark Research. Retrieved 13 March 2013.
- Milius, S (1 August 1998). "Glow-in-the-dark shark has killer smudge". Science News. Retrieved 13 March 2013.
- Haddock, Steven H.D.; Moline, M.A., Case, J.F (2010). "Bioluminescence in the sea". Annual Review of Marine Science 2: 443–493. Bibcode:2010ARMS....2..443H. doi:10.1146/annurev-marine-120308-081028. PMID 21141672.
- Peter Vršanský, Dušan Chorvát, Ingo Fritzsche, Miroslav Hain and Robert Ševčík (2012). "Light-mimicking cockroaches indicate Tertiary origin of recent terrestrial luminescence". Naturwissenschaften 99 (9): 739–749. doi:10.1007/s00114-012-0956-7.
- Stanger-Hall, K.F.; Lloyd, J.E.; Hillis, D.M. (2007). "Phylogeny of North American fireflies (Coleoptera: Lampyridae): implications for the evolution of light signals". Molecular Phylogenetics and Evolution 45 (1): 33–49. doi:10.1016/j.ympev.2007.05.013. PMID 17644427.
- Bioluminescence. Bio.davidson.edu (2005-10-25). Retrieved on 20 October 2011.
- Marek, Paul; Papaj, Daniel; Yeager, Justin; Molina, Sergio; Moore, Wendy. "Bioluminescent aposematism in millipedes". Current Biology 21 (18): R680–R681. doi:10.1016/j.cub.2011.08.012.
- Long-wave sensitivity in deep-sea stomiid dragonfish with far-red bioluminescence: evidence for a dietary origin of the chlorophyll-derived retinal photosensitizer of Malacosteus niger. by R.H. Douglas, C.W. Mullineaux, and J.C. Partridge
- Ow, D.W. and Wood, K.V. and DeLuca, M. and de Wet, J.R. and Helinski, D.R. and Howell, S.H. (1986). "Transient and stable expression of the firefly luciferase gene in plant cells and transgenic plants". Science 234 (4778) (American Association for the Advancement of Science). pp. 856––856. ISSN 0036-8075.
- Bioluminescence Questions and Answers. Siobiolum.ucsd.edu. Retrieved on 20 October 2011.
- (4 May 2013) One Per Cent: Grow your own living lights The New Scientist, Issue 2915, Retrieved 7 May 2013
- Dr. Chris Riley, “Glowing plants reveal touch sensitivity”, BBC 17 May 2000.
|Wikimedia Commons has media related to: Bioluminescence|
|Wikisource has the text of the 1920 Encyclopedia Americana article Luminosity of Animals.|
- UCSB Biological Sciences: Bioluminescence
- MBARI: Gonyaulax Bioluminescence
- UF/IFAS: glow-worms
- TED: Glowing life in an underwater world (video)
- Maui Magazine: Night Lights: Bioluminescence
- DefenceTalk: Military eyes glowing secrets of fireflies, others
- Smithsonian Ocean Portal: Bioluminescent animals photo gallery
- The Nature of Animal Light by E. Newton Harvey (1920) Philadelphia & London: J. B. Lippencott
- Bioluminescent bloom makes beach a magical minefield New Scientist, 14 May 2012.
- National Geographic: Bioluminescence