Ice worms (also written as ice-worms or iceworms) are enchytraeid

annelids The annelids (Annelida , from Latin ', "little ring"), also known as the segmented worms, are a large phylum, with over 22,000 extant species including ragworms, earthworms, and leeches. The species exist in and have adapted to various ecolo ...

of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

''Mesenchytraeus''. The majority of the

species In biology, a species is the basic unit of Taxonomy (biology), classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of ...

in the genus are abundant in gravel beds or the banks of

river A river is a natural flowing watercourse, usually freshwater Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the ...

ine habitats, but the best-known members of the genus are found in

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

ice. They include the only annelid worms known to spend their entire lives in

ice, and some of the few

metazoan Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in ...

s to complete their entire life cycle at conditions below . They were discovered in a wide range of environments, which include level snowfields, steep avalanche cones, crevasse walls, glacial rivers and pools, and hard glacier ice. These organisms are unique in that they can simply move between tightly packed ice crystals. They utilize setae, which are small bristles found on the outside of their bodies, to grip the ice and pull themselves along. Ice Worm against Fingernail

The genus contains 77

, including the North American glacier ice worm (''

Mesenchytraeus solifugus ''Mesenchytraeus solifugus'', commonly called an ice worm, is a species of oligochaete worm that inhabits coastal glaciers in northwestern North America. ''M. solifugus'' is dark brown and grows to about 15 mm long and 0.5 mm wide ...

'') and the Yosemite snow worm ('' Mesenchytraeus gelidus''). Ice worms eat snow algae and bacteria. They live at zero degrees Celsius (32 degrees Fahrenheit), but if temperatures dip even slightly below that, according to a

Washington State University Washington State University (Washington State, WSU, or informally Wazzu) is a public land-grant research university with its flagship, and oldest, campus in Pullman, Washington. Founded in 1890, WSU is also one of the oldest land-grant uni ...

researcher, the worms die.

Species

The genus contains 77

. They are the following: *''

Mesenchytraeus affinis 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, but the best-known members of th ...

'' Michaelsen, 1901 *''

Mesenchytraeus altus 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, but the best-known members of th ...

'' Welch, 1917 *''

Mesenchytraeus americanus 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, but the best-known members of th ...

'' Bell, 1942 *''

Mesenchytraeus anisodiverticulus 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, but the best-known members of th ...

'' Shen, Chen & Xie, 2012 *''

Mesenchytraeus antaeus 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, but the best-known members of th ...

'' Rota & Brinkhurst, 2000 *''

Mesenchytraeus arcticus 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, but the best-known members of th ...

'' Bell, 1962 *''

Mesenchytraeus argentatus 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, but the best-known members of th ...

'' Nurminen, 1973b *'' Mesenchytraeus armatus'' (Levinsen, 1884) :*'' Mesenchytraeus armatus armatus'' (Levinsen, 1884) :*'' Mesenchytraeus armatus kananaskis'' Dash, 1970 *'' Mesenchytraeus asiaticus'' Eisen, 1904 *'' Mesenchytraeus atriaphorus'' Altman, 1936 *'' Mesenchytraeus beringensis'' Eisen, 1904 *'' Mesenchytraeus beumeri'' (Michaelsen, 1886b) *'' Mesenchytraeus bungei'' Michaelsen, 1901 *'' Mesenchytraeus cejkai'' Cernosvitov, 1937d *'' Mesenchytraeus celticus'' Southern, 1909 *'' Mesenchytraeus chaunus'' Piper, MacLean & Christensen, 1982 *'' Mesenchytraeus chromophorus'' Altman, 1936 *'' Mesenchytraeus crenobius'' Timm, 1994 *'' Mesenchytraeus diplobulbosus'' Bell, 1949 *''

Mesenchytraeus diverticulatus 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, but the best-known members of t ...

'' Piper, MacLean & Christensen, 1982 *'' Mesenchytraeus eastwoodi'' Eisen, 1904 *'' Mesenchytraeus eltoni'' Stephenson, 1925 *''

Mesenchytraeus falciformis 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, but the best-known members of t ...

'' Eisen, 1878 *'' Mesenchytraeus flavidus'' Michaelsen, 1887 *'' Mesenchytraeus flavus'' (Levinsen, 1884) *'' Mesenchytraeus fontinalis'' Eisen, 1904 :*'' Mesenchytraeus fontinalis fontinalis'' Eisen, 1904 :*'' Mesenchytraeus fontinalis gracilis'' Eisen, 1904 *'' Mesenchytraeus franciscanus'' Eisen, 1904 *'' Mesenchytraeus fuscus'' Eisen, 1904 :*'' Mesenchytraeus fuscus fuscus'' Eisen, 1904 :*''

Mesenchytraeus fuscus inermis 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, but the best-known members of th ...

'' Eisen, 1904 *'' Mesenchytraeus gaudens'' Cognetti, 1903a *'' Mesenchytraeus gelidus'' Welch, 1916 *'' Mesenchytraeus gigachaetus'' Xie, 2012 *'' Mesenchytraeus glandulosus'' (Levinsen, 1884) *'' Mesenchytraeus grandis'' Eisen, 1904 *'' Mesenchytraeus grebnitzkyi'' Michaelsen, 1901 *'' Mesenchytraeus groenlandicus'' Nielsen & Christensen, 1959 *'' Mesenchytraeus hamiltoni'' Healy, 1996b *'' Mesenchytraeus harrimani'' Eisen, 1904 *'' Mesenchytraeus hydrius'' Welch, 1919a *'' Mesenchytraeus johanseni'' Welch, 1919b *'' Mesenchytraeus kincaidi'' Eisen, 1904 *'' Mesenchytraeus kontrimavichusi'' Piper, MacLean & Christensen, 1982 *'' Mesenchytraeus konyamensis'' Michaelsen, 1916 *'' Mesenchytraeus kuehnelti'' Dózsa-Farkas, 1991a *'' Mesenchytraeus kuril'' Healy & Timm, 2000 *''

Mesenchytraeus lusitanicus 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, but the best-known members of th ...

'' Collado, Martínez-Ansemil, and Giani, 1993 *'' Mesenchytraeus macnabi'' Bell, 1942 *'' Mesenchytraeus maculatus'' Eisen, 1904 *'' Mesenchytraeus magnus'' Altman, 1936 *'' Mesenchytraeus melanocephalus'' Christensen & Dózsa-Farkas, 1999 *'' Mesenchytraeus minimus'' Altman, 1936 *'' Mesenchytraeus mirabilis'' Eisen, 1878 *'' Mesenchytraeus monochaetus'' Bretscher, 1900 *''

Mesenchytraeus monodiverticulus 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, but the best-known members of t ...

'' Shen, Chen & Xie, 2012 *'' Mesenchytraeus monothecatus'' Bell, 1945 *'' Mesenchytraeus multispinus'' (Grube, 1851) *'' Mesenchytraeus nanus'' Eisen, 1904 *'' Mesenchytraeus obscurus'' Eisen, 1904 *'' Mesenchytraeus ogloblini'' Černosvitov, 1928b *'' Mesenchytraeus orcae'' Eisen, 1904 *'' Mesenchytraeus pedatus'' Eisen, 1904 *'' Mesenchytraeus pelicensis'' Issel, 1905c *''

Mesenchytraeus penicillus 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, but the best-known members of th ...

'' Eisen, 1904 *'' Mesenchytraeus primaevus'' Eisen, 1878 *'' Mesenchytraeus rhithralis'' Healy & Fend, 2002 *'' Mesenchytraeus sanguineus'' Nielsen & Christensen, 1959 *'' Mesenchytraeus setchelli'' Eisen, 1904 *''

'' (Emery, 1898) :*'' Mesenchytraeus solifugus solifugus'' (Emery, 1898) :*'' Mesenchytraeus solifugus rainierensis'' Welch, 1916 *'' Mesenchytraeus straminicolus'' Rota, 1995 *'' Mesenchytraeus sveni'' Christensen & Dózsa-Farkas, 1999 *'' Mesenchytraeus svetae'' Piper, MacLean & Christensen, 1982 *'' Mesenchytraeus tetrapodus'' Timm, 1978 *'' Mesenchytraeus torbeni'' Christensen & Dózsa-Farkas, 1999 *'' Mesenchytraeus tundrus'' Piper, MacLean & Christensen, 1982 *'' Mesenchytraeus unalaskae'' Eisen, 1904 *'' Mesenchytraeus variabilis'' Cejka, 1914 *'' Mesenchytraeus vegae'' Eisen, 1904 *'' Mesenchytraeus viivi'' Timm, 1978 *'' Mesenchytraeus vshivkovae'' Timm, 1994 ''Mesenchytraeus franzi'' is a junior synonym of '' Cognettia clarae''. ''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.''

References

External links

Seattle Times Article on Iceworms
{{DEFAULTSORT:Ice Worm Enchytraeidae

Species

See also

References

External links