Ice worm

Ice worm
Mesenchytraeus solifugus
Scientific classification
Kingdom:	Animalia
Phylum:	Annelida
Class:	Clitellata
Subclass:	Oligochaeta
Order:	Haplotaxida
Family:	Enchytraeidae
Genus:	Mesenchytraeus Eisen, 1878[1]
Type species
Mesenchytraeus primaevus Eisen, 1878
Species
See text

Ice worms (also written as ice-worms or iceworms) are enchytraeid annelids of the genus Mesenchytraeus. The majority of the species in the genus are abundant in gravel beds or the banks of riverine habitats,^[2][3] but the most well-known members of the genus are found in glacial ice. They are the only annelid worms known to spend their entire lives in glacial ice,^[4] and the largest metazoan to complete their entire life cycle at conditions below 0 °C (32 °F).^[5]

The genus contains 76 species, including M. solifugus, M. harrimani, M. kuril, M. maculatus and M. obscurus.^[6][7][8]

History

The earliest written records of ice worms were by the Ottoman explorer Evliya Çelebi in 1648 while he was in Uludağ (known in ancient times as "Olympus") near Bursa, Turkey. Evliyâ writes that the worms were found in the "midst of ice and snow as old as the creation." He describes them as having the usual size of very small cucumbers, having forty feet, forty black spots, and red eyes, and being composed entirely of ice that "melts quickly away." He said the that worms were very rare and were presented as gifts to kings as they were purportedly aphrodisiacs and had health benefits. He also repeats rumors of how ice worms in the Caucasus mountains were supposedly as "big as dogs".^[9] Although the phenomenon had been described by many geographers and travelers since antiquity, it was dismissed by scientists as a myth until late nineteenth-century research proved that a species of dark brown or black worm (Mesenchytraeus solifugus) does indeed live in glaciers and permanent snow.

In North America, the first ice worms species were discovered in 1887 in Alaska, on the Muir Glacier. These glacier ice worms can be found on glaciers in Alaska, Washington, Oregon and British Columbia. They have not been found in other glaciated regions of the world.

Description

The specific name solifugus for the North American species, Mesenchytraeus solifugus, is Latin for "sun-avoiding," as ice worms retreat underneath the ice before dawn. Enzymes in ice worms have very low optimal temperatures, and can be denatured at even a few degrees above 0 °C (32 °F). When ice worms are exposed to temperatures as modest as 5 °C (41 °F), their membrane structures disassociate and fall apart (i.e., "melt") causing the worm itself to "liquefy." Ice worms are several centimeters long, and can be black, blue, or white. They come to the surface of the glaciers in the evening and morning. On Suiattle Glacier in the North Cascades, population counts indicated over 7 billion ice worms.

It is not known how ice worms tunnel through the ice. Some scientists believe they travel through microscopic fissures in ice sheets, while others believe they secrete some chemical which can melt ice by lowering its freezing point, like an antifreeze. They feed on snow algae.

Species

The genus contains 76 species. They are the following:^[6][7]

Mesenchytraeus franzi is a junior synonym of Cognettia clarae.^[6] Mesenchytraeus megachaetae Shen, Chen & Xie, 2011 has been renamed Mesenchytraeus gigachaetus Xie, 2012 due to the previous name being preoccupied by Mesenchytraeus megachaetae Bretscher, 1901, a junior synonym of Mesenchytraeus armatus.^[7][10]

In popular culture

• An old Canadian song "When the Ice Worms Nest Again" that may date from the Klondike gold rush of 1898 jokes about how cold it is in northern Canada. Versions of the song has been released commercially by Wilf Carter, Edith Fowke and Richard Johnston, Alan Mills, and Murray Adaskin, among others.^[11]
• Scottish-born Canadian poet of the Yukon Robert W. Service wrote the poem "The Ballad of the Ice-worm Cocktail" in 1940, in which a fake ice worm made of spaghetti is the subject of a bar bet. This may have contributed to the impression that ice worms are mythical creatures.^[12]
• In the annual February Ice Worm Festival of Cordova, Alaska, a long imitation ice worm is paraded through the streets like a Chinese new year dragon dance.^[12][13][14]

See also

• Project Iceworm

References

External links

• North Cascade Glaciers ice worms research
• Seattle Times Article on Iceworms