Difference between revisions of "Bioluminescence" - New World Encyclopedia

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==Types of organisms==
 
==Types of organisms==
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Bioluminescence occurs in a great diversity of taxa, including [[bacterium|bacteria]], [[fungus|fungi]], [[dinoflagellate]]s, [[annelid]]s, [[ctenophore]]s (comb jellies),  (jellyfish), [[mollusk]]s, [[crustacean]]s, [[echinoderm]]s, and [[insect]]s, and [[fish]]. 
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"It is the predominant source of light in the largest fraction of the habitable volume of the earth, the deep ocean" (Haddock et al. 2006) .
  
 
Ninety percent of [[deep-sea fish|deep-sea marine life]] is estimated to produce bioluminescence in one form or another. Most marine light-emission belongs in the [[blue]] and [[green]] [[electromagnetic radiation|light spectrum]], the wavelengths that can transmit through the [[seawater]] most easily. However, certain [[loose jawed fish]] emit [[red]] and [[infrared]] light.
 
Ninety percent of [[deep-sea fish|deep-sea marine life]] is estimated to produce bioluminescence in one form or another. Most marine light-emission belongs in the [[blue]] and [[green]] [[electromagnetic radiation|light spectrum]], the wavelengths that can transmit through the [[seawater]] most easily. However, certain [[loose jawed fish]] emit [[red]] and [[infrared]] light.
  
 
At least two chemicals are required. The one which produces the light is generically called a "luciferin" and the one that drives or catalyzes the reaction is called a "luciferase."
 
  
  
  
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"Nearly all comb-jellies (Phylum Ctenophora) can make light, but the best-known species Pleurobrachia has not been found to luminesce. Because ctenophores can produce brilliant colors from diffraction through their comb plates, people get the impression that they are seeing bioluminescence."
  
"Nearly all comb-jellies (Phylum Ctenophora) can make light, but the best-known species Pleurobrachia has not been found to luminesce. Because ctenophores can produce brilliant colors from diffraction through their comb plates, people get the impression that they are seeing bioluminescence."
 
"It is the predominant source of light in the largest fraction of the habitable volume of the earth, the deep ocean" (Haddock et al. 2006) .
 
  
 
In contrast, bioluminescence is essentially absent (with a few exceptions) in fresh water, even in Lake Baikal (Haddock et al. 2006).
 
In contrast, bioluminescence is essentially absent (with a few exceptions) in fresh water, even in Lake Baikal (Haddock et al. 2006).

Revision as of 23:51, 5 April 2007

Bioluminescence is the production and emission of light by a living organism as the result of a chemical reaction during which chemical energy is converted to light energy. It is widespread in the marine environment, but rare in terrestrial and especially freshwater environments. Examples include emission of visible light by dinoflagellates, jellyfish, squid, copepods, fireflies, and many other organisms belonging to a wide diversity of taxonomic groups.

Characteristics of the phenomenon

File:Red tide bioluminescence at midnight.jpg
Image of bioluminescent red tide event of 2005 at a beach in Carlsbad California showing brilliantly glowing crashing waves containing billions of Lingulodinium polyedrum dinoflagellates. The blue light is a result of a luciferase enzyme

Simply defined, bioluminescence is "light produced by a chemical reaction" that "originates in an organism" (Haddock et al. 2006). The name bioluminescence originates from the Greek bios for "living" and the Latin lumen for "light."

Bioluminescence is a form of luminescence, or "cold light" emission; less than 20% of the light generates thermal radiation]]. Bioluminescence should not be confused with fluorescence or phosphorescence. In fluorescence, the molecular absorption of a photon triggers the emission of another photon with a longer wavelength. In other words, the energy originates from an external source of light, which is absorbed and almost immediately emitted (Haddock et al. 2006). In phosphorescence, the material absorbs an external source of light as well, but does not immediately re-emit the radiation it absorbs. The absorbed radiation may be re-emitted at a lower intensity for up to several hours.

Chimiluminescence (or chemoluminescence) is the general term for production of ight via a chemical reaction, and thus bioluminescence is a subset of chemiluminescence, but where the light-producing chemical reaction occurs inside an organism (Haddock et al. 2006).

Bioluminescence is generated by an enzyme-catalyzed chemoluminescence reaction, wherein the pigment luciferin is oxidized by the enzyme luciferase. In other wrods, the chemical luciferin is the one that produces light and the chemical luciferase is the one that drives or catalyzes the reaction (Haddock et al. 2006). Adenosine triphosphate (ATP) is involved in most instances. The chemical reaction can occur either within or outside of the cell.

In bacteria, the expression of genes related to bioluminescence is controlled by an operon (key nucleotide sequence) called the Lux operon.

Types of organisms

Bioluminescence occurs in a great diversity of taxa, including bacteria, fungi, dinoflagellates, annelids, ctenophores (comb jellies), (jellyfish), mollusks, crustaceans, echinoderms, and insects, and fish.

"It is the predominant source of light in the largest fraction of the habitable volume of the earth, the deep ocean" (Haddock et al. 2006) .

Ninety percent of deep-sea marine life is estimated to produce bioluminescence in one form or another. Most marine light-emission belongs in the blue and green light spectrum, the wavelengths that can transmit through the seawater most easily. However, certain loose jawed fish emit red and infrared light.



"Nearly all comb-jellies (Phylum Ctenophora) can make light, but the best-known species Pleurobrachia has not been found to luminesce. Because ctenophores can produce brilliant colors from diffraction through their comb plates, people get the impression that they are seeing bioluminescence."


In contrast, bioluminescence is essentially absent (with a few exceptions) in fresh water, even in Lake Baikal (Haddock et al. 2006).

Non-marine bioluminescence is less widely distributed, but a larger variety in colours is seen. The two best-known forms of land bioluminescence are fireflies and New Zealand 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 only exist) at night, following a circadian rhythm.


Bioluminescence may be generated by symbiotic organisms carried within a larger organism.


Artistic rendering of bioluminescent Antarctic krill (watercolor by Uwe Kils)

Adaptations for bioluminescence

There are four main accepted theories for the evolution of bioluminescent traits:



A squid which changes the color of its luminescence to match moonlight and sunlight.


A siphonophore which uses red light to lure fish to its tentacles.


Tiny single-celled organisms that make the sea sparkle.


Fishes like Malacosteus and Aristostomias with their own "night vision" light.


Crustaceans which send out coded messages to their own species when it is time to mate.


Camouflage

Main article: Camouflage

Attraction

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. Some fish, however, use a non-bioluminescent lure.

The cookiecutter shark uses bioluminescence for camouflage, but a small patch on its underbelly remains dark and appears as a small fish to large predatory fish like tuna and mackerel. When these fish try to consume the "small fish", they are bitten by the shark.

Dinoflagellates have an interesting twist on this mechanism. When a predator of plankton is sensed through motion in the water, the dinoflagellate luminesces. This in turn attracts even larger predators which will consume the would-be predator of the dinoflagellate.

The attraction of mates is another proposed mechanism of bioluminescent action. This is seen actively in fireflies who use periodic flashing in their abdomens to attract mates in the mating season. In the marine environment this has only been well-documented in certain small crustacean called ostracod. It has been suggested that pheromones may be used for long-distance communication, and bioluminescent used at close range to "home in" on the target.

The honey mushroom attracts insects using bioluminescence so that the insects will help disseminate the fungus' spores into the environment.

Repulsion

Certain squid and small crustaceans use bioluminescent chemical mixtures, or bioluminescent bacterial slurries in the same way as many squid use ink. A cloud of luminescence is expulsed, confusing or repelling a potential predator while the squid or crustacean escapes to safety.

Communication

Bioluminescence is thought to play a direct role in communication between bacteria (see quorum sensing). It promotes the symbiotic induction of bacteria into host species, and may play a role in colony aggregation.



Almost all marine bioluminescence is blue in color, for two related reasons.

First, blue-green light (wavelength around 470 nm) transmits furthest in water. The reason that underwater photos usually look blue is because red light is quickly absorbed as you descend.

The second reason for bioluminescence to be blue is that most organisms are sensitive only to blue light — they lack the visual pigments which can absorb longer (yellow, red) or shorter (indigo, ultraviolet) wavelengths.




A notable exception to this "rule" is Malacosteid family of fishes (known as Loosejaws), which produce red light and are able to see this light when other organisms can not.


The light produced by species like Malacosteus, Aristostomias, and Pachystomias has such long wavelengths that it is nearly infrared and is barely visible to a human eye. In addition, they can produce typical blue-green light from a separate organ.



Why Red Light

The ability to produce red light, gives the Malacosteidae a huge advantage in the deep sea. Although the light doesn't travel very far, it lets them see their prey, without alerting the prey or any potentially curious predators. So these fish produce a red signal meant only for themselves, and a blue-green signal, perhaps used as a warning to others.


Biotechnology

File:Glowing tobacco plant.jpg
"Artificial" bioluminescence induced by genetic engineering of a tobacco plant.

Bioluminescent organisms are a target for many areas of research. Luciferase systems are widely used in the field of genetic engineering as reporter genes (see picture left). 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) is a key experimental model for symbiosis, quorum sensing, and bioluminescence.

The structure of photophores, the light producing organs in bioluminescent organisms, are being investigated by industrial designers.

Some proposed applications of engineered bioluminescence include:

  • Christmas trees that do not need lights, reducing dangerous electronics
  • glowing trees to line highways to save government electricity bills
  • agricultural crops and domestic plants that luminesce when they need watering
  • new methods for detecting bacterial contamination of meats and other foods
  • bio-identifiers for escaped convicts and mental patients
  • detecting bacterial species in suspicious corpses
  • novelty pets that bioluminesce (rabbits, mice, fish etc.)

Organisms that bioluminesce

All cells produce some form of bioluminescence within the electromagnetic spectrum, but most is neither visible nor noticeable to the naked eye. Every organism's bioluminescence is unique in wavelength, duration, timing and regularity of flashes. Below follows a list of organisms which have been observed to have visible bioluminescence.

Non-marine organisms

Fish

  • cookie cutter shark
  • Marine hatchetfish
  • Anglerfish
  • Flashlight fish
  • Pineconefish
  • Porichthys
  • Beebe's monster
  • Gulper Eel
  • Many rattails

Marine invertebrates

Plankton and microbes

  • Dinoflagellates
  • Vibrionaceae (e.g. Vibrio fischeri, Vibrio harveyi, Vibrio phosphoreum)

References
ISBN links support NWE through referral fees

Haddock, S.H.D.; McDougall, C.M.; Case, J.F. "The Bioluminescence Web Page", http://lifesci.ucsb.edu/~biolum/ (created 1997; updated 2006; accessed XX/XX/XX).

Young, R.E. and R.M. Mencher. (1980) Bioluminescence in mesopelagic squid: diel color change during counterillumination. Science, 208:1286-1288.


Young, R.E. and C.F.E. Roper. (1976) Bioluminescent countershading in midwater animals: evidence from living squid. Science, 191:1046-1048.


See also

  • biophoton
  • Milky Sea
  • De Phenomenis in Orbe Lunae
  • Foxfire
  • List of light sources
  • Alba (rabbit)

External links

bn:জীব দ্যুতি de:Biolumineszenz es:Bioluminiscencia eo:Lumantaj bestoj fr:Bioluminescence is:Lífljómun it:Bioluminescenza he:ביולומינסנציה mk:Биолуминисценција nl:Bioluminescentie no:Bioluminescens nn:Bioluminescens pl:Bioluminescencja fi:Bioluminesenssi sv:Mareld tg:Биолюминесентсия tr:Biyoluminesans


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