bioluminescence

Flying and glowing firefly, Photinus pyralis

Female glowworm, Lampyris noctiluca

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.

History

The French pharmacologist Raphaël Dubois carried out early work on bioluminescence.^[1]

Before the development of the safety lamp for use in coal mines, dried fish skins were used in Britain and Europe as a weak source of light.^[2][3]

Overview

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.

By etymology, bioluminescence is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light".

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).^[4] 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.^[5]

Distribution

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".^[6]

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.^[7] In these animals, photoreceptors control the illumination to match the brightness of the background.^[7] 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.^[8]

Mimicry

Firefly larva

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.^[9]

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.^[10][11]

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.^[12] A South American giant cockroach, Lucihormetica luckae, uses bioluminescence to mimic the toxic Pyrophorus beetle for defensive purposes.^[13]

Attracting mates

The attraction of mates is seen actively in fireflies, which use periodic flashing in their abdomens to attract mates in the mating season.^[14]

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".

Distraction

A bobtail squid, one of many bioluminescent cephalopods – 63 out of 100 genera of cuttlefish and squid contain species with the ability.^[15]

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.^{[citation needed]}

Warning

Aposematism is a widely used function of bioluminescence. It is suggested that many firefly larvae glow to repel predators. Millipedes have been shown to glow for the same purpose.^[16]

Communication

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.^{[citation needed]}

Illumination

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.^[17]

Biotechnology

Autoluminograph of a genetically-engineered glowing tobacco plant^[18]

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.^[19][20]

The gene that makes firefly's tails glow has been added to mustard plants. The plants glow faintly for an hour when touched, but a sensitive camera is needed to see the glow.^[21]

References

External links

• UCSB Biological Sciences: Bioluminescence
• MBARI: Gonyaulax Bioluminescence
• www.caymankayaks.com
• 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

Aquatic ecosystems – general and freshwater components General Aquatic ecosystems Acoustic ecology Agent-based models Algal bloom Anoxic waters Aquatic adaptation Aquatic animals Aquatic biodiversity research Aquatic biomonitoring Aquatic insects Aquatic layers Aquatic mammals Aquatic plants Aquatic predation Aquatic respiration Aquatic science Aquatic toxicology Benthos Bioluminescence Biomass Cascade effect Colored dissolved organic matter Dead zone Ecohydrology Eutrophication Fisheries science Food chain Food web GIS and aquatic science Hydrobiology Hypoxia Isotope analysis Microbial ecology Microbial food web Microbial loop Nekton Neuston Particle Photic zone Phytoplankton Plankton Pleuston Productivity Ramsar Convention Schooling Sediment trap Siltation Spawning Substrate Thermal pollution Trophic level Underwater camouflage and mimicry Water column Zooplankton More... Freshwater Freshwater ecosystems Brackish marsh Freshwater biology Freshwater biomes Freshwater fish Freshwater marsh Freshwater swamp forest Hyporheic zone Lake ecosystems Landscape limnology Limnology Lake stratification Macrophyte Pond Fish pond Rheotaxis River ecosystems Stream bed Stream pool Trophic state index Upland and lowland Water garden Wetland Environmental quality More... Ecoregions Freshwater ecoregions List of freshwater ecoregions Marine ecoregions List of marine ecoregions Ecology of the Everglades Ecology of the San Francisco Estuary Ecosystem of the North Pacific Subtropical Gyre Freshwater ecology of Maharashtra   Aquatic ecosystems – marine components Marine Marine ecosystem f-ratio Iron fertilization Iron Hypothesis Large marine ecosystem Marine biology Marine chemistry Marine snow Ocean nourishment Oceanic physical-biological process Ocean turbidity Photophore Thorson's rule Upwelling Whale fall More... Marine life forms Census of Marine Life Coastal fish Coral reef fish Deep sea communities Deep sea creature Deep sea fish Deep-water coral Demersal fish Marine bacteriophage Marine invertebrates Marine larval ecology Marine mammal Marine reptile Marine vertebrate Paradox of the plankton Pelagic fish Seabird Seashore wildlife Wild fisheries Marine habitats Bay mud Black smokers Coastal biogeomorphology Cold seeps Coral reefs Davidson Seamount Estuaries Intertidal ecology Intertidal wetlands Kelp forests Hydrothermal vents Lagoons Mangroves Marine biomes Marine habitats Mudflats Rocky shores Salt marshes Seagrass meadows Sponge reefs Tide pools Issues Ecological values of mangrove Fisheries and climate change HERMIONE Marine conservation Marine conservation activism Marine pollution Marine Protected Area

Modelling ecosystems – trophic components General Abiotic component Abiotic stress Behaviour Biogeochemical cycle Biomass Biotic component Biotic stress Carrying capacity Competition Ecosystem Ecosystem ecology Ecosystem model Keystone species List of feeding behaviours Metabolic theory of ecology Productivity Producers Autotrophs Chemosynthesis Chemotrophs Foundation species Mixotrophs Myco-heterotrophy Mycotroph Organotrophs Photoheterotrophs Photosynthesis Photosynthetic efficiency Phototrophs Primary nutritional groups Primary production Consumers Apex predator Bacterivore Carnivores Chemoorganotroph Foraging Generalist and specialist species Intraguild predation Herbivores Heterotroph Heterotrophic nutrition Insectivore Mesopredator release hypothesis Omnivores Optimal foraging theory Predation Prey switching Decomposers Chemoorganoheterotrophy Decomposition Detritivores Detritus Microorganisms Archaea Bacteriophage Environmental microbiology Lithoautotroph Lithotrophy Microbial cooperation Microbial ecology Microbial food web Microbial intelligence Microbial loop Microbial mat Microbial metabolism Phage ecology Food webs Biomagnification Ecological efficiency Ecological pyramid Energy flow Food chain Trophic level Example webs Cold seeps Hydrothermal vents Intertidal Kelp forests Lakes North Pacific Subtropical Gyre Rivers San Francisco Estuary Soil Tide pool Processes Ascendency Bioaccumulation Cascade effect Climax community Competitive exclusion principle Consumer-resource systems Copiotrophs Dominance Ecological network Ecological succession Energy quality Energy Systems Language f-ratio Feed conversion ratio Feeding frenzy Mesotrophic soil Nutrient cycle Oligotroph Paradox of the plankton Trophic cascade Trophic mutualism Trophic state index Defense/counter Animal coloration Antipredator adaptations Camouflage Deimatic behaviour Herbivore adaptations to plant defense Mimicry Plant defense against herbivory Predator avoidance in schooling fish

Modelling ecosystems – other components Population ecology Abundance Allee effect Depensation Ecological yield Effective population size Intraspecific competition Logistic function Malthusian growth model Maximum sustainable yield Overpopulation in wild animals Overexploitation Population cycle Population dynamics Population modeling Population size Predator–prey equations Recruitment Resilience Small population size Stability Species Biodiversity Density-dependent inhibition Ecological effects of biodiversity Ecological extinction Endemic species Flagship species Gradient analysis Indicator species Introduced species Invasive species Latitudinal gradients in species diversity Minimum viable population Neutral theory Occupancy-abundance relationship Population viability analysis Priority effect Rapoport's rule Relative abundance distribution Relative species abundance Species diversity Species homogeneity Species richness Species distribution Species-area curve Umbrella species Species interaction Antibiosis Biological interaction Commensalism Community ecology Ecological facilitation Interspecific competition Mutualism Storage effect Spatial ecology Biogeography Cross-boundary subsidy Ecocline Ecotone Ecotype Disturbance Edge effects Foster's rule Habitat fragmentation Ideal free distribution Intermediate Disturbance Hypothesis Island biogeography Landscape ecology Landscape epidemiology Landscape limnology Metapopulation Patch dynamics r/K selection theory Source–sink dynamics Niche Ecological niche Ecological trap Ecosystem engineer Environmental niche modelling Guild Habitat Marine habitats Limiting similarity Niche apportionment models Niche construction Niche differentiation Other networks Assembly rules Bateman's principle Bioluminescence Ecological collapse Ecological debt Ecological deficit Ecological energetics Ecological indicator Ecological threshold Ecosystem diversity Emergence Extinction debt Kleiber's law Liebig's law of the minimum Marginal value theorem Thorson's rule Xerosere Other Allometry Alternative stable state Balance of nature Biological data visualization Constructal theory Ecocline Ecological economics Ecological footprint Ecological forecasting Ecological humanities Ecological stoichiometry Ecopath Ecosystem based fisheries Endolith Evolutionary ecology Functional ecology Industrial ecology Macroecology Microecosystem Natural environment Regime shift Systems ecology Theoretical ecology List of ecology topics