- Pompeii worm
Taxobox
name = Pompeii worm
image_width = 200px
regnum =Animal ia
phylum = Annelida
classis =Polychaeta
ordo =Terebellida
familia =Alvinellidae
genus = "Alvinella "
species = "A. pompejana"
binomial = "Alvinella pompejana"
binomial_authority = Desbruyéres and Laubier, 1980The Pompeii worm ("Alvinella pompejana") is a deep-sea
polychaete vermiformextremophile found only athydrothermal vent s in thePacific Ocean , discovered in the early 1980s off theGalápagos Islands by French researchers.Attaching themselves to
black smoker s, the worms have been found to thrive at temperatures of up to 80°C (176°F), making the Pompeii worm the most heat-tolerant complex animal known to science after the tardigrades (or water bears), which are able to survive temperatures over 150ºC.Pompeii worms get their name from the Roman city of
Pompeii that was destroyed during an eruption ofMount Vesuvius in AD 79. Its family nameAlvinellidae and genus name "Alvinella" both derive from DSV "Alvin", the three-person submersible vehicle used during the discovery of hydrothermal vents and their fauna during the late 1970s. The familyAlvinellidae contains eight other species, but none match the Pompeii worm's heat tolerance.Biology
Reaching a length of up to 13 centimeters (5 inches), Pompeii worms are a pale grey with "hairy" backs; these "hairs" are actually colonies of bacteria which are thought to afford the worm some degree of insulation. Glands on the worm's back secrete a mucus which the bacteria feed on (see "
symbiosis "). The Pompeii worms form large aggregate colonies enclosed in delicate, paper-thin tubes.Pompeii worms have a feather-shaped head. The plume of tentacle-like structures on it are
gill s, coloured red byhaemoglobin .Symbiotic Bacteria
While it is not yet known precisely how the Pompeii worm survives these severe vent conditions, scientists suspect the answer lies in the fleece-like bacteria on the worm's back; this layer may be up to a centimetre thick. The bacteria may possess special
protein s, "eurythermalenzyme s", providing the bacteria—and by extension the worms—protection from a wide range of temperatures. It is plausible that the bacteria also provide thermal insulation. Studies are hampered by the difficulties of sampling; to date, Pompeii worms have not surviveddecompression .Study of the Pompeii worm's seemingly life-sustaining bacteria could lead to significant advances in the
biochemical ,pharmaceutical ,textile ,paper anddetergent industries.Behavior
Pompeii worms simultaneously keep their heads (including the gills) in much cooler water while their tails are exposed to hot water (see below). Since their internal temperature has yet to be measured, it is plausible that a Pompeii worm survives exposure to hot water by dissipating heat through its head to keep its internal temperature within the realm previously known to be compatible with animal survival.
Thought to subsist on vent
microbe s, the Pompeii worm pokes its head out of its tube home to feed and breathe. It is the posterior end that is exposed to extreme temperatures; the anterior end stays at a much more comfortable 22°C (72°F).External links
* [http://www.exploratorium.edu/aaas-2001/dispatches/thermal_worm.html Exploratorium: The worm that boasts the world's hottest lifestyle]
* [http://www.ocean.udel.edu/extreme2002/creatures/pompeiiworm/ Mission to the Abyss: includes an interactive 3D rendering of a Pompeii worm]
* [http://news.nationalgeographic.com/news/2004/12/1208_041208_pompeii_worms.html National Geographic article about the Pompeii worm]
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