Thursday, March 19, 2009

Bioluminescent Under the Arctic Abyss

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. Its name is a hybrid word, originating from the Greek bios for "living" and the Latin lumen "light". Adenosine triphosphate is involved in most instances.


Photo: rci.rutgers.edu

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 has appeared independently several times during evolution.

Bioluminescence occurs in marine vertebrates and invertebrates, as well as microorganisms and terrestrial animals. Symbiotic organisms carried within larger organisms are also known to bioluminesce.



Some of Bioluminescent creatures give off light continually. Others flash their lights on and off by mixing their chemicals on queue or by covering their light organs with a flap of skin. The flashlight fish has a light-producing organ near its eyes that is covered with an eyelid-type flap. The fish can flash its light by opening and closing this flap. These creatures produce light for a variety of reasons. For some, it is a warning to stay away. For others, it is a form of camouflage. Certain species of shallow water squid give off light to blend in with the moonlight. Some creatures use their light for navigation.

Certain fish species use bioluminescence as a form of "night light". Some use it for communication. Certain species of crustaceans send out coded signals to others of their own kind during mating season. Other creatures use bioluminescence as a trap. The anglerfish uses a lighted "lure" on the top of its head to attract its prey. When the unsuspecting animal is within striking distance, the angler vacuums it down with a lightening-fast snap of its powerful jaws. Whatever the reason for producing this dazzling light show, it remains as one of the natural world's most bizarre and spectacular facts.

Sources: wikipedia.org, seasky.org

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