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80-405: Deepwater may refer to ocean water in the abyssal zone , hadal zone , or other deep ocean zones. Deepwater may also refer to: Abyssal zone As there is no light, photosynthesis cannot occur, and there are no plants producing molecular oxygen (O 2 ), which instead primarily comes from ice that had melted long ago from the polar regions . The water along the seafloor of this zone

160-456: A black lining able to keep the light from any bioluminescent fish prey which they have swallowed from attracting larger predators. The sea-firefly is a small crustacean living in sediment. At rest it emits a dull glow but when disturbed it darts away leaving a cloud of shimmering blue light to confuse the predator. During World War II it was gathered and dried for use by the Japanese army as

240-651: A bright enough wake to be detected; a German submarine was sunk in the First World War , having been detected in this way. The Navy was interested in predicting when such detection would be possible, and hence guiding their own submarines to avoid detection. Among the anecdotes of navigation by bioluminescence is one recounted by the Apollo 13 astronaut Jim Lovell , who as a Navy pilot had found his way back to his aircraft carrier USS Shangri-La when his navigation systems failed. Turning off his cabin lights, he saw

320-401: A common ancestor. However, he found this hypothesis to be false, with different organisms having major differences in the composition of their light-producing proteins. He spent the next 30 years purifying and studying the components, but it fell to the young Japanese chemist Osamu Shimomura to be the first to obtain crystalline luciferin. He used the sea firefly Vargula hilgendorfii , but it

400-433: A long-lasting glow which the fish can control. The glowing esca is dangled or waved about to lure small animals to within striking distance of the fish. The cookiecutter shark uses bioluminescence to camouflage its underside by counter-illumination, 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

480-405: A majority are found in symbiotic relationships that involve fish, squids, crustaceans etc. as hosts. Most luminous bacteria inhabit the sea, dominated by Photobacterium and Vibrio . In the symbiotic relationship, bacterium benefit from having a source of nourishment and a refuge to grow. Hosts obtain these bacterial symbionts either from the environment, spawning , or the luminous bacterium

560-485: A role in the regulation of luminescence in many species of bacteria. Small extracellularly secreted molecules stimulate the bacteria to turn on genes for light production when cell density, measured by concentration of the secreted molecules, is high. Pyrosomes are colonial tunicates and each zooid has a pair of luminescent organs on either side of the inlet siphon. When stimulated by light, these turn on and off, causing rhythmic flashing. No neural pathway runs between

640-512: A similar role in these ecosystems as plants do in the sunlit regions above. A new insight into the complexity of the abyssal environment has been provided by a team of researchers from the Scottish Society of Marine Sciences. They have found that manganese nodules on the deep sea floor produce free oxygen from water molecules. The manganese nodules act as a kind of battery as they contain different metals, and they release oxygen into

720-426: A source of light during clandestine operations. The larvae of railroad worms ( Phrixothrix ) have paired photic organs on each body segment, able to glow with green light; these are thought to have a defensive purpose. They also have organs on the head which produce red light; they are the only terrestrial organisms to emit light of this color. Aposematism is a widely used function of bioluminescence, providing

800-542: A warning that the creature concerned is unpalatable. It is suggested that many firefly larvae glow to repel predators; some millipedes glow for the same purpose. Some marine organisms are believed to emit light for a similar reason. These include scale worms , jellyfish and brittle stars but further research is needed to fully establish the function of the luminescence. Such a mechanism would be of particular advantage to soft-bodied cnidarians if they were able to deter predation in this way. The limpet Latia neritoides

880-416: Is evolving with their host. Coevolutionary interactions are suggested as host organisms' anatomical adaptations have become specific to only certain luminous bacteria, to suffice ecological dependence of bioluminescence. Bioluminescence is widely studied amongst species located in the mesopelagic zone, but the benthic zone at mesopelagic depths has remained widely unknown. Benthic habitats at depths beyond

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960-419: Is expelled, distracting or repelling a potential predator, while the animal escapes to safety. The deep sea squid Octopoteuthis deletron may autotomize portions of its arms which are luminous and continue to twitch and flash, thus distracting a predator while the animal flees. Dinoflagellates may use bioluminescence for defense against predators . They shine when they detect a predator, possibly making

1040-546: Is in the blue and green light spectrum . However, some loose-jawed fish emit red and infrared light, and the genus Tomopteris emits yellow light. The most frequently encountered bioluminescent organisms may be the dinoflagellates in the surface layers of the sea, which are responsible for the sparkling luminescence sometimes seen at night in disturbed water. At least 18 genera of these phytoplankton exhibit luminosity. Luminescent dinoflagellate ecosystems are present in warm water lagoons and bays with narrow openings to

1120-432: Is largely devoid of molecular oxygen, resulting in a death trap for organisms unable to quickly return to the oxygen-enriched water above or to survive in the low-oxygen environment. This region also contains a much higher concentration of nutrient salts, like nitrogen , phosphorus , and silica , due to the large amount of dead organic material that drifts down from the ocean zones above and decomposes. The region below

1200-425: Is no conclusive evidence that the cockroaches are bioluminescent. While most marine bioluminescence is green to blue, some deep sea barbeled dragonfishes in the genera Aristostomias , Pachystomias and Malacosteus emit a red glow. This adaptation allows the fish to see red-pigmented prey, which are normally invisible to other organisms in the deep ocean environment where red light has been filtered out by

1280-406: Is prevalent in the pelagic zone such as counter-illumination may not be functional or relevant in the benthic realm. Bioluminescence in bathyal benthic species still remains poorly studied due to difficulties of the collection of species at these depths. Bioluminescence has several functions in different taxa. Steven Haddock et al. (2010) list as more or less definite functions in marine organisms

1360-582: Is regenerated from the oxidized (oxyluciferin) form, allowing it to recombine with aequorin, in preparation for a subsequent flash. Photoproteins are thus enzymes , but with unusual reaction kinetics. Furthermore, some of the blue light released by aequorin in contact with calcium ions is absorbed by a green fluorescent protein , which in turn releases green light in a process called resonant energy transfer . Overall, bioluminescence has arisen over 40 times in evolutionary history. In evolution , luciferins tend to vary little: one in particular, coelenterazine ,

1440-518: Is that bioluminescence has evolved independently at least 40 times. Bioluminescence in fish began at least by the Cretaceous period. About 1,500 fish species are known to be bioluminescent; the capability evolved independently at least 27 times. Of these, 17 involved the taking up of bioluminous bacteria from the surrounding water while in the others, the intrinsic light evolved through chemical synthesis. These fish have become surprisingly diverse in

1520-544: Is the light emitting pigment for nine phyla (groups of very different organisms), including polycystine radiolaria , Cercozoa ( Phaeodaria ), protozoa , comb jellies , cnidaria including jellyfish and corals , crustaceans , molluscs , arrow worms and vertebrates ( ray-finned fish ). Not all these organisms synthesise coelenterazine: some of them obtain it through their diet. Conversely, luciferase enzymes vary widely and tend to be different in each species. Bioluminescence occurs widely among animals, especially in

1600-534: Is the only known bioluminescent terrestrial mollusk. Pulses of light are emitted from a gland near the front of the foot and may have a communicative function, although the adaptive significance is not fully understood. Bioluminescence is used by a variety of animals to mimic other species. Many species of deep sea fish such as the anglerfish and dragonfish make use of aggressive mimicry to attract prey . They have an appendage on their heads called an esca that contains bioluminescent bacteria able to produce

1680-401: Is the only known freshwater gastropod that emits light. It produces greenish luminescent mucus which may have an anti-predator function. The marine snail Hinea brasiliana uses flashes of light, probably to deter predators. The blue-green light is emitted through the translucent shell, which functions as an efficient diffuser of light. Communication in the form of quorum sensing plays

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1760-420: Is used for camouflage by counterillumination , 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

1840-495: The Deepsea Challenger , had penetrated to a depth of 10,898 meters (35,756 ft). The relative sparsity of primary producers means that the majority of organisms living in the abyssal zone depend on the marine snow that falls from oceanic layers above. The biomass of the abyssal zone actually increases near the seafloor as most of the decomposing material and decomposers rest on the seabed. The composition of

1920-404: The firefly luciferase . Generically, this reaction can be described as: Instead of a luciferase, the jellyfish Aequorea victoria makes use of another type of protein called a photoprotein , in this case specifically aequorin . When calcium ions are added, rapid catalysis creates a brief flash quite unlike the prolonged glow produced by luciferase. In a second, much slower step, luciferin

2000-506: The Oplophoridae family, uses its photophores to emit light, and can secrete a bioluminescent substance when in the presence of a predator. This secretory mechanism is common among prey fish. Many cephalopods , including at least 70 genera of squid , are bioluminescent. Some 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

2080-472: The abdomen when flying and a green light from the thorax when they are disturbed or moving about on the ground. The former is probably a sexual attractant but the latter may be defensive. Larvae of the click beetle Pyrophorus nyctophanus live in the surface layers of termite mounds in Brazil. They light up the mounds by emitting a bright greenish glow which attracts the flying insects on which they feed. In

2160-422: The abyssal plain depends on the depth of the sea floor. Above 4000 meters the seafloor usually consists of calcareous shells of foraminifera, zooplankton , and phytoplankton . At depths greater than 4000 meters shells dissolve, leaving behind a seafloor of brown clay and silica from dead zooplankton and phytoplankton. Chemosynthetic bacteria support large and diverse communities near hydrothermal vents , filling

2240-464: The abyssal zone are the pressure and darkness caused by the zone's depth. Many organisms living in this zone have evolved to minimize internal air spaces, such as swim bladders . This adaptation helps to protect them from the extreme pressure, which can reach around 75 MPa (11,000 psi). The absence of light also spawned many different adaptations, such as having large eyes and the ability to produce their own light ( bioluminescence ). Large eyes would allow

2320-665: The abyssal zone is the sparsely inhabited hadal zone . The region above is the bathyal zone . The deep trenches or fissures that plunge down thousands of meters below the ocean floor (for example, the mid-oceanic trenches such as the Mariana Trench in the Pacific ) are almost unexplored. Previously, only the bathyscaphe Trieste , the remote control submarine Kaikō and the Nereus have been able to descend to these depths. However, as of March 25, 2012 one vehicle,

2400-533: The abyssal zone. Due to the zone's depth, increasing global temperatures do not affect it as quickly or drastically as the rest of the world, but the zone is still afflicted by ocean acidification . Pollutants, such as plastics, are also present in this zone. Plastics are especially bad for the abyssal zone because these organisms have evolved to eat or try to eat anything that moves or appears to be detritus, resulting in organisms consuming plastics instead of nutrients. Both ocean acidification and pollution are decreasing

2480-433: The already small biomass that resides within the abyssal zone. Another problem caused by humans is overfishing . Even though no fishery can fish for organisms anywhere near the abyssal zone, they can still cause harm in deeper waters. The abyssal zone depends on dead organisms from the upper zones sinking to the seafloor, since the ecosystem lacks producers due to a lack of sunlight. As fish and other animals are removed from

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2560-444: The amount of pollution not only in the abyssal zone, but in the ocean as a whole, and would physically destroy habitats and the seafloor. Sediment plumes generated by mining activities can spread widely, affecting filter feeders and smothering marine life. The potential release of toxic chemicals and heavy metals from mining equipment and disturbed seabed materials could lead to chemical pollution, while noise from machinery can disrupt

2640-413: The animal access to the seafloor and the nutrients located there. There are also animals that spend their time in the upper portion of the abyssal zone, some of which even occasionally spend time in the zone directly above, the bathyal zone. While there are a number of different fish species representing many different groups and classes, like Actinopterygii (ray-finned fish), there are no known members of

2720-480: The animal's light organ. Bioluminescence is used in a variety of ways and for different purposes. The cirrate octopod Stauroteuthis syrtensis uses emits bioluminescence from its sucker like structures. These structures are believed to have evolved from what are more commonly known as octopus suckers. They do not have the same function as the normal suckers because they no longer have any handling or grappling ability due its evolution of photophores . The placement of

2800-496: The animals obtain it through their diet. Conversely, luciferases vary widely between different species. Bioluminescence has arisen over 40 times in evolutionary history . Both Aristotle and Pliny the Elder mentioned that damp wood sometimes gives off a glow. Many centuries later Robert Boyle showed that oxygen was involved in the process, in both wood and glowworms. It was not until the late nineteenth century that bioluminescence

2880-468: The animals responsible for luminescence. He mentions pellucids, crustaceans (to which he ascribes the milky whiteness of the water), and cancers (shrimps and crabs). Under the microscope he described the "luminous property" to be in the brain, resembling "a most brilliant amethyst about the size of a large pin's head". Charles Darwin noticed bioluminescence in the sea, describing it in his Journal : While sailing in these latitudes on one very dark night,

2960-534: The atmosphere" was probably responsible. Daniel Pauly comments that Darwin "was lucky with most of his guesses, but not here", noting that biochemistry was too little known, and that the complex evolution of the marine animals involved "would have been too much for comfort". Bioluminescence attracted the attention of the United States Navy in the Cold War , since submarines in some waters can create

3040-429: The behavior and communication of marine animals. Physical disturbances to the seabed may destroy geological features and their associated ecosystems. Furthermore, changes in water quality and the disruption of carbon sequestration processes, where organic carbon is stored in the deep sea, could have broader environmental impacts, including contributing to climate change. The slow rate of change in deep-sea environments and

3120-444: The chemical mechanisms or to prove what function the light serves. In some cases the function is unknown, as with species in three families of earthworm ( Oligochaeta ), such as Diplocardia longa , where the coelomic fluid produces light when the animal moves. The following functions are reasonably well established in the named organisms. In many animals of the deep sea, including several squid species, bacterial bioluminescence

3200-426: The class Chondrichthyes (animals such as sharks, rays, and chimaeras) that make the abyssal zone their primary or constant habitat. Whether this is due to the limited resources, energy availability, or other physiological constraints is unknown. Most Chondrichthyes species only go as deep as the bathyal zone. Creatures that live in the abyssal zone include:     Climate change has had negative effects on

3280-522: The darkness and do not waste energy on developing and maintaining bright or complex patterns. The abyssal zone is made up of many different types of organisms, including microorganisms, crustaceans, molluscs (bivalves, snails, and cephalopods), different classes of fishes, and possibly some animals that have yet to be discovered. Most of the fish species in this zone are described as demersal or benthopelagic fishes. Demersal fish are fish whose habitats are on or near (typically less than five meters from)

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3360-472: The dead insect thus assisting in the dispersal of both bacteria and nematodes. A similar reason may account for the many species of fungi that emit light. Species in the genera Armillaria , Mycena , Omphalotus , Panellus , Pleurotus and others do this, emitting usually greenish light from the mycelium , cap and gills . This may attract night-flying insects and aid in spore dispersal, but other functions may also be involved. Quantula striata

3440-435: The deep can feed on them. When a whale carcass falls down to the abyssal zone, this is called a whale fall . The carcass of the whale can create complex ecosystems for organisms in the depths. Benthic organisms in the abyssal zone would need to have evolved morphological traits that could either keep them out of oxygen-depleted water above the sea floor or enable them to extract oxygen from the water above, while also allowing

3520-757: The deep ocean and control their light with the help of their nervous system, using it not just to lure prey or hide from predators, but also for communication. All bioluminescent organisms have in common that the reaction of a "luciferin" and oxygen is catalyzed by a luciferase to produce light. McElroy and Seliger proposed in 1962 that the bioluminescent reaction evolved to detoxify oxygen, in parallel with photosynthesis. Thuesen, Davis et al. showed in 2016 that bioluminescence has evolved independently 27 times within 14 fish clades across ray-finned fishes. The oldest of these appears to be Stomiiformes and Myctophidae. In sharks, bioluminescence has evolved only once. Genomic analysis of octocorals indicates that their ancestor

3600-435: The detection and use of any light available, no matter how small. Commonly, animals in the abyssal zone are bioluminescent, producing blue light, because light in the blue wavelength range is attenuated over greater travel distances than other wavelengths. Due to this lack of light, complex patterns and bright colors are not needed. Most fish species have evolved to be transparent, red, or black so that they better blend in with

3680-695: The development of increased eye sensitivity and enhanced visual signals. If selection were to favor a mutation in the oxygenase enzyme required for the breakdown of pigment molecules (molecules often associated with spots used to attract a mate or distract a predator) it could have eventually resulted in external luminescence in tissues. Rees et al. use evidence gathered from the marine luciferin coelenterazine to suggest that selection acting on luciferins may have arisen from pressures to protect oceanic organisms from potentially deleterious reactive oxygen species (e.g. H 2 O 2 and O 2 ). The functional shift from antioxidation to bioluminescence probably occurred when

3760-580: The environment. Because it was previously thought that only plants and algae produce dark oxygen (oxygen produced without light), this can be seen as a scientific breakthrough. Organisms that live at this depth have had to evolve to overcome challenges provided by the abyssal zone. Fish and invertebrates had to evolve to withstand the sheer cold and intense pressure found at this level. Not only did they have to find ways to hunt and survive in constant darkness, but they also had to thrive in an ecosystem that has less oxygen and biomass, energy sources and prey, than

3840-417: The female lights up to attract males. The defense mechanisms for bioluminescent organisms can come in multiple forms; startling prey, counter-illumination, smoke screen or misdirection, distractive body parts, burglar alarm, sacrificial tag or warning coloration. The shrimp family Oplophoridae Dana use their bioluminescence as a way of startling the predator that is after them. Acanthephyra purpurea , within

3920-434: The following: defensive functions of startle, counterillumination (camouflage), misdirection (smoke screen), distractive body parts, burglar alarm (making predators easier for higher predators to see), and warning to deter settlers; offensive functions of lure, stun or confuse prey, illuminate prey, and mate attraction/recognition. It is much easier for researchers to detect that a species is able to produce light than to analyze

4000-402: The glowing wake of the ship, and was able to fly to it and land safely. The French pharmacologist Raphaël Dubois carried out work on bioluminescence in the late nineteenth century. He studied click beetles ( Pyrophorus ) and the marine bivalve mollusc Pholas dactylus . He refuted the old idea that bioluminescence came from phosphorus, and demonstrated that the process was related to

4080-517: The glowworm require air for light to be produced. Harvey notes that in 1753, J. Baker identified the flagellate Noctiluca "as a luminous animal" "just visible to the naked eye", and in 1854 Johann Florian Heller (1813–1871) identified strands ( hyphae ) of fungi as the source of light in dead wood. Tuckey , in his posthumous 1818 Narrative of the Expedition to the Zaire , described catching

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4160-510: The laboratory, luciferase-based systems are used in genetic engineering and biomedical research. Researchers are also investigating the possibility of using bioluminescent systems for street and decorative lighting, and a bioluminescent plant has been created. 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. This experimental form of illumination avoided

4240-439: The light is bacteriogenic, produced by symbiotic bacteria such as those from the genus Vibrio ; in others, it is autogenic, produced by the animals themselves. In a general sense, the principal chemical reaction in bioluminescence involves a light-emitting molecule and an enzyme , generally called luciferin and luciferase , respectively. Because these are generic names, luciferins and luciferases are often distinguished by

4320-514: The long lifespans and reproductive cycles of abyssal species mean that recovery from such disturbances could take decades or centuries. Bioluminescence Bioluminescence is the production and emission of light by living organisms . It is a form of chemiluminescence . Bioluminescence occurs widely in marine vertebrates and invertebrates , as well as in some fungi , microorganisms including some bioluminescent bacteria , and terrestrial arthropods such as fireflies . In some animals,

4400-553: The lure, they are bitten by the shark. Female Photuris fireflies sometimes mimic the light pattern of another firefly, Photinus , to attract its males as prey. In this way they obtain both food and the defensive chemicals named lucibufagins , which Photuris cannot synthesize. South American giant cockroaches of the genus Lucihormetica were believed to be the first known example of defensive mimicry, emitting light in imitation of bioluminescent, poisonous click beetles. However, doubt has been cast on this assertion, and there

4480-463: The marine environment, use of luminescence for mate attraction is chiefly known among ostracods , small shrimp-like crustaceans , especially in the family Cyprididae . Pheromones may be used for long-distance communication, with bioluminescence used at close range to enable mates to "home in". A polychaete worm, the Bermuda fireworm creates a brief display, a few nights after the full moon, when

4560-403: The mesopelagic are also poorly understood due to the same constraints. Unlike the pelagic zone where the emission of light is undisturbed in the open sea, the occurrence of bioluminescence in the benthic zone is less common. It has been attributed to the blockage of emitted light by a number of sources such as the sea floor, and inorganic and organic structures. Visual signals and communication that

4640-563: The necessity of using candles which risked sparking explosions of firedamp . In 1920, the American zoologist E. Newton Harvey published a monograph, The Nature of Animal Light , summarizing early work on bioluminescence. Harvey notes that Aristotle mentions light produced by dead fish and flesh, and that both Aristotle and Pliny the Elder (in his Natural History ) mention light from damp wood. He records that Robert Boyle experimented on these light sources, and showed that both they and

4720-416: The ocean, the frequency and amount of dead material reaching the abyssal zone decreases. Deep sea mining operations could cause problems for the abyssal zone in the future. The talks and planning for this industry are already under way. Deep sea mining could be disastrous for this extremely fragile ecosystem since there are many ecological dangers posed by mining for deep sea minerals. Mining could increase

4800-402: The ocean. A different effect is the thousands of square miles of the ocean which shine with the light produced by bioluminescent bacteria, known as mareel or the milky seas effect . Bioluminescence is abundant in the pelagic zone, with the most concentration at depths devoid of light and surface waters at night. These organisms participate in diurnal vertical migration from the dark depths to

4880-441: The only unifying mechanism is the role of molecular oxygen ; often there is a concurrent release of carbon dioxide (CO 2 ). For example, the firefly luciferin/luciferase reaction requires magnesium and ATP and produces CO 2 , adenosine monophosphate (AMP) and pyrophosphate (PP) as waste products. Other cofactors may be required, such as calcium (Ca ) for the photoprotein aequorin , or magnesium (Mg ) ions and ATP for

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4960-556: The open sea, including fish , jellyfish , comb jellies , crustaceans , and cephalopod molluscs; in some fungi and bacteria ; and in various terrestrial invertebrates, nearly all of which are beetles . In marine coastal habitats, about 2.5% of organisms are estimated to be bioluminescent, whereas in pelagic habitats in the eastern Pacific, about 76% of the main taxa of deep-sea animals have been found to be capable of producing light. More than 700 animal genera have been recorded with light-producing species. Most marine light-emission

5040-578: The oxidation of a specific compound, which he named luciferin , by an enzyme . He sent Harvey siphons from the mollusc preserved in sugar. Harvey had become interested in bioluminescence as a result of visiting the South Pacific and Japan and observing phosphorescent organisms there. He studied the phenomenon for many years. His research aimed to demonstrate that luciferin, and the enzymes that act on it to produce light, were interchangeable between species, showing that all bioluminescent organisms had

5120-466: The phenomenon. Today, the two prevailing hypotheses (both concerning marine bioluminescence) are those put forth by Howard Seliger in 1993 and Rees et al. in 1998. Seliger's theory identifies luciferase enzymes as the catalyst for the evolution of bioluminescent systems. It suggests that the original purpose of luciferases was as mixed-function oxygenases. As the early ancestors of many species moved into deeper and darker waters natural selection favored

5200-434: The photophores are within the animals oral reach, which leads researchers to suggest that it uses it bioluminescence to capture and lure prey. Fireflies use light to attract mates . Two systems are involved according to species; in one, females emit light from their abdomens to attract males; in the other, flying males emit signals to which the sometimes sedentary females respond. Click beetles emit an orange light from

5280-440: The predator itself more vulnerable by attracting the attention of predators from higher trophic levels. Grazing copepods release any phytoplankton cells that flash, unharmed; if they were eaten they would make the copepods glow, attracting predators, so the phytoplankton's bioluminescence is defensive. The problem of shining stomach contents is solved (and the explanation corroborated) in predatory deep-sea fishes: their stomachs have

5360-444: The reflected glare of these livid flames, was not so utterly obscure, as over the rest of the heavens. Darwin also observed a luminous "jelly-fish of the genus Dianaea", noting that: "When the waves scintillate with bright green sparks, I believe it is generally owing to minute crustacea. But there can be no doubt that very many other pelagic animals, when alive, are phosphorescent." He guessed that "a disturbed electrical condition of

5440-400: The retainment of functional eyes for organisms to detect bioluminescence. Organisms often produce bioluminescence themselves, rarely do they generate it from outside phenomena. However, there are occasions where bioluminescence is produced by bacterial symbionts that have a symbiotic relationship with the host organism. Although many luminous bacteria in the marine environment are free-living,

5520-401: The sea presented a wonderful and most beautiful spectacle. There was a fresh breeze, and every part of the surface, which during the day is seen as foam, now glowed with a pale light. The vessel drove before her bows two billows of liquid phosphorus, and in her wake she was followed by a milky train. As far as the eye reached, the crest of every wave was bright, and the sky above the horizon, from

5600-432: The seafloor. Most fish species fit into that classification, because the seafloor contains most of the abyssal zone's nutrients; therefore, the most complex food web or greatest biomass would be in this region of the zone. Organisms in the abyssal zone rely on the natural processes of higher ocean layers. When animals from higher ocean levels die, their carcasses occasionally drift down to the abyssal zone, where organisms in

5680-456: The species or group, e.g. firefly luciferin . In all characterized cases, the enzyme catalyzes the oxidation of the luciferin. In some species, the luciferase requires other cofactors , such as calcium or magnesium ions, and sometimes also the energy-carrying molecule adenosine triphosphate (ATP). In evolution , luciferins vary little: one in particular, coelenterazine , is found in 11 different animal phyla , though in some of these,

5760-399: The strength of selection for antioxidation defense decreased as early species moved further down the water column. At greater depths exposure to ROS is significantly lower, as is the endogenous production of ROS through metabolism. While popular at first, Seliger's theory has been challenged, particularly on the biochemical and genetic evidence that Rees examines. What remains clear, however,

5840-411: The surface at night, dispersing the population of bioluminescent organisms across the pelagic water column. The dispersal of bioluminescence across different depths in the pelagic zone has been attributed to the selection pressures imposed by predation and the lack of places to hide in the open sea. In depths where sunlight never penetrates, often below 200m, the significance of bioluminescent is evident in

5920-407: The twentieth and early twenty-first century was published recently. In 1932 E. N. Harvey was among the first to propose how bioluminescence could have evolved. In this early paper, he suggested that proto-bioluminescence could have arisen from respiratory chain proteins that hold fluorescent groups. This hypothesis has since been disproven, but it did lead to considerable interest in the origins of

6000-483: The upper zones. To survive in these conditions, many fish and other organisms developed a much slower metabolism, and require much less oxygen than those in upper zones. Many animals also move very slowly to conserve energy. Their reproduction rates are also very slow, to decrease competition and conserve energy. Animals here typically have flexible stomachs and mouths, so that when scarce prey are found they can consume as many as possible. Other challenges faced by life in

6080-487: The water column. These fish are able to utilize the longer wavelength to act as a spotlight for its prey that only they can see. The fish may also use this light to communicate with each other to find potential mates. The ability of the fish to see this light is explained by the presence of specialized rhodopsin pigment. The mechanism of light creation is through a suborbital photophore that utilizes gland cells which produce exergonic chemical reactions that produce light with

6160-449: The zooids, but each responds to the light produced by other individuals, and even to light from other nearby colonies. Communication by light emission between the zooids enables coordination of colony effort, for example in swimming where each zooid provides part of the propulsive force. Some bioluminous bacteria infect nematodes that parasitize Lepidoptera larvae. When these caterpillars die, their luminosity may attract predators to

6240-575: Was another ten years before he discovered the chemical's structure and published his 1957 paper Crystalline Cypridina Luciferin . Shimomura, Martin Chalfie , and Roger Y. Tsien won the 2008 Nobel Prize in Chemistry for their 1961 discovery and development of green fluorescent protein as a tool for biological research. Harvey wrote a detailed historical account on all forms of luminescence in 1957. An updated book on bioluminescence covering also

6320-423: Was bioluminescent as long as 540 million years ago. Bioluminescence is a form of chemiluminescence where light energy is released by a chemical reaction. This reaction involves a light-emitting pigment, the luciferin , and a luciferase , the enzyme component. Because of the diversity of luciferin/luciferase combinations, there are very few commonalities in the chemical mechanism. From currently studied systems,

6400-437: Was properly investigated. The phenomenon is widely distributed among animal groups, especially in marine environments. On land it occurs in fungi, bacteria and some groups of invertebrates , including insects . The uses of bioluminescence by animals include counterillumination camouflage, mimicry of other animals, for example to lure prey, and signaling to other individuals of the same species, such as to attract mates. In

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