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Is-orm ( Danish )

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for metan-is-orme se Hesiocaeca methanicola

Is-orme er arter af ormeslægten Mesenchytraeus, som lever i gletsjeris. De omfatter Mesenchytraeus solifugus, M. harrimani, M. kuril, M. maculatus og M. obscurus.

De første is-ormearter blev opdaget i 1887 i AlaskaMuir Glacier [2]. Disse is-orme findes på gletsjere i Alaska, Washington, Oregon og Britisk Columbia. De er ikke blevet fundet i andre isdækkede områder i verden. Navnet "solifugus" er latin for "sol-undvigende", da is-ormene kryber under isen før daggry. Enzymer i is-orme har meget lave optimale temperaturer og kan blive denatureret ved ganske få plusgrader celsius. Når is-orme udsættes for temperaturer højere end 5 grader celsius, falder deres membranstrukturer fra hinanden ("smelter") hvilket forårsager, at ormen bliver flydende. Is-orme er adskillige centimeter lange, og kan være sorte, blå eller hvide. Is-ormene kommer til overfladen af gletsjerne om aftenen og morgenen for at spise snealger. På Suiattle Glacier i North Cascades indikerer gletsjertællinger, at populationen på denne gletsjer er over 7 milliarder is-orme.

Det vides ikke hvordan is-orme bevæger sig gennem isen. Nogle forskere mener, at de kravler gennem mikroskopiske revner i islaget, mens andre tror de udskiller sekreter med kemikalier, som kan smelte isen ved at mindske isens frysepunkt, ligesom antifrysevæske.

Kilder/referencer

  1. ^ Kathryn A. Coates, Jan M. Locke, Brenda M. Healy & Mark J. Wetzel (26. august 2008). "The aphanoneuran and clitellate Annelida occurring in the United States and Canada: families Enchytraeidae and Propappidae". University of Illinois at Urbana-Champaign. Hentet 22. januar 2010. CS1 maint: Multiple names: authors list (link)
  2. ^ Kimi Ross (2009). "The Glacier Ice Worm". BellaOnline.

Eksterne henvisninger

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Is-orm: Brief Summary ( Danish )

provided by wikipedia DA
for metan-is-orme se Hesiocaeca methanicola

Is-orme er arter af ormeslægten Mesenchytraeus, som lever i gletsjeris. De omfatter Mesenchytraeus solifugus, M. harrimani, M. kuril, M. maculatus og M. obscurus.

De første is-ormearter blev opdaget i 1887 i AlaskaMuir Glacier . Disse is-orme findes på gletsjere i Alaska, Washington, Oregon og Britisk Columbia. De er ikke blevet fundet i andre isdækkede områder i verden. Navnet "solifugus" er latin for "sol-undvigende", da is-ormene kryber under isen før daggry. Enzymer i is-orme har meget lave optimale temperaturer og kan blive denatureret ved ganske få plusgrader celsius. Når is-orme udsættes for temperaturer højere end 5 grader celsius, falder deres membranstrukturer fra hinanden ("smelter") hvilket forårsager, at ormen bliver flydende. Is-orme er adskillige centimeter lange, og kan være sorte, blå eller hvide. Is-ormene kommer til overfladen af gletsjerne om aftenen og morgenen for at spise snealger. På Suiattle Glacier i North Cascades indikerer gletsjertællinger, at populationen på denne gletsjer er over 7 milliarder is-orme.

Det vides ikke hvordan is-orme bevæger sig gennem isen. Nogle forskere mener, at de kravler gennem mikroskopiske revner i islaget, mens andre tror de udskiller sekreter med kemikalier, som kan smelte isen ved at mindske isens frysepunkt, ligesom antifrysevæske.

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Ice worm

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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 best-known members of the genus are found in glacial ice. They include the only annelid worms known to spend their entire lives in glacial ice,[4] and some of the few metazoans to complete their entire life cycle at conditions below 0 °C (32 °F).[5]

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.

Unknown species of ice worm

The genus contains 77 species, including the North American glacier ice worm (Mesenchytraeus solifugus) and the Yosemite snow worm (Mesenchytraeus gelidus).[6][7][8]

Ice worms eat snow algae and bacteria.[9] They live at zero degrees Celsius (32 degrees Fahrenheit), but if temperatures dip even slightly below that, according to a Washington State University researcher, the worms die.[10]

Species

The genus contains 77 species. They are the following:[6][7][11]

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][12]

See also

References

  1. ^ Kathryn A. Coates; Jan M. Locke; Brenda M. Healy; Mark J. Wetzel (August 26, 2008). "The aphanoneuran and clitellate Annelida occurring in the United States and Canada: families Enchytraeidae and Propappidae". University of Illinois at Urbana-Champaign. Retrieved January 22, 2010.
  2. ^ Paula L. Hartzell & Daniel H. Shain (2009). "Glacier Ice Worms". In Daniel H. Shain (ed.). Annelids in Modern Biology. Wiley-Blackwell. p. 305. ISBN 9780470455197.
  3. ^ Brenda Healy & Steve Fend (2002). "The occurrence of Mesenchytraeus (Enchytraeidae: Oligochaeta) in riffle habitats of north-west American rivers, with description of a new species". Journal of Natural History. 36 (1): 15–23. doi:10.1080/713833842. S2CID 84290342.
  4. ^ Shain, Daniel H.; Carter, Melissa R.; Murray, Kurt P.; Maleski, Karen A.; Smith, Nancy R.; McBride, Taresha R.; Michalewicz, Lisa A.; Saidel, William M. (2000). "Morphologic characterization of the ice worm Mesenchytraeus solifugus". Journal of Morphology. 246 (3): 192–7. doi:10.1002/1097-4687(200012)246:3<192::AID-JMOR3>3.0.CO;2-B. PMID 11077431. S2CID 30143253.
  5. ^ A.H. Farrell, K.A.Hohenstein, & D.H. Shain (2004). "Molecular adaptation in the ice worm, Mesenchytraeus solifugus: divergence of energetic-associated genes". Journal of Molecular Evolution. 59 (5): 666–673. Bibcode:2004JMolE..59..666F. doi:10.1007/s00239-004-2658-z. PMID 15693622. S2CID 22139929.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  6. ^ a b c Rüdiger M. Schmelz & Rut Collado (2012). "An updated checklist of currently accepted species of Enchytraeidae (Oligochaeta, Annelida)". VTI Agriculture and Forestry Research. 357: 67–87.
  7. ^ a b c Rüdiger M. Schmelz & Rut Collado (2015). "Checklist of taxa of Enchytraeidae (Oligochaeta): an update" (PDF). Soil Organisms. 87 (2): 149–152. Archived from the original (PDF) on 2016-12-20. Retrieved 2017-01-23.
  8. ^ Qi Shen, Jing Chen, & Zhicai Xie (2012). "Mesenchytraeus monodiverticulus sp. nov. (Annelida: Cliterllata: Enchytraeidae) from Changbai Mountain, with a key to Mesenchytraeus with enlarged chaetae". Proceedings of the Biological Society of Washington. 125 (3): 215–227. doi:10.2988/12-08.1. S2CID 84234028.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  9. ^ "Ice Worms (Mesenchytraeus solifugus) and Their Habitats on North Cascade Glaciers-North Cascade Glacier Climate Project". North Cascade Glacier Climate Project. November 6, 2008. Archived from the original on 2009-02-09. Retrieved 17 July 2021.
  10. ^ Greenfieldboyce, Nell (July 13, 2021). "It's Summer, And That Means The Mysterious Return Of Glacier Ice Worms". NPR. Retrieved 17 July 2021.
  11. ^ Qi Shen, Jing Chen, & Zhicai Xie (2012). "Mesenchytraeus monodiverticulus sp. nov. (Annelida: Clitellata: Enchytraeidae) from Changbai Mountain, with a key to Mesenchytraeus with enlarged chaetae". Proceedings of the Biological Society of Washington. 125 (3): 215–227. doi:10.2988/12-08.1. S2CID 84234028.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  12. ^ Zhicai Xie (2012). "Mesenchytraeus gigachaetus, new name, a replacement name for Mesenchytraeus megachaetus Shen et al., 2011". Proceedings of the Biological Society of Washington. 125 (1): 18. doi:10.2988/11-41.1. S2CID 86642220.

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Ice worm: Brief Summary

provided by wikipedia EN

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 the genus are found in glacial ice. They include the only annelid worms known to spend their entire lives in glacial ice, and some of the few metazoans to complete their entire life cycle at conditions below 0 °C (32 °F).

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.

Unknown species of ice worm

The genus contains 77 species, including the North American glacier ice worm (Mesenchytraeus solifugus) 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 researcher, the worms die.

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Mesenchytraeus ( French )

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Mesenchytraeus (les vers de glace) est un genre de vers annélides de la famille des Enchytraeidae. Leur nom vient du fait qu’ils vivent exclusivement dans la glace.

Espèces

Habitat

Le premier ver de glace est découvert en 1887 en Alaska sur le glacier Muir[1]. Présents dans des glaciers, ils sont présents de l’Alaska à l’Oregon en passant par la Colombie-Britannique et l’État de Washington.

Description

L’espèce « solifugus » tire son nom du mot latin signifiant « qui évite le soleil » car le ver se cache sous la glace juste avant l’aube. Le ver ne supporte pas les températures positives et sa structure membraneuse peut littéralement « fondre » au-dessus de 5 °C.

Les vers peuvent atteindre une taille de plusieurs centimètres. Ils ont une couleur noire, bleue ou blanche. Sur le glacier Suiattle dans la région des North Cascades, on a décompté plus de 7 milliards de vers de glace. On ne sait pas très bien comment les vers se déplacent dans la glace. Certains scientifiques pensent qu’ils passent dans des microfissures présentes dans la glace tandis que d’autres pensent que les vers sécrètent un fluide modifiant la température de solidification de la glace (sorte d’antigel) en vue de pouvoir avancer. Les vers se nourrissent d'algues de neige.

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Mesenchytraeus: Brief Summary ( French )

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Mesenchytraeus (les vers de glace) est un genre de vers annélides de la famille des Enchytraeidae. Leur nom vient du fait qu’ils vivent exclusivement dans la glace.

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冰蟲 ( Chinese )

provided by wikipedia 中文维基百科

冰蟲是指Mesenchytraeus屬的環節動物的總稱,生活於北極地區的冰層中。

Mesenchytraeus solifugus是最早發現的種類,於1887年在阿拉斯加發現。是地球上極少數能在攝氏0度以下仍能生存的生物。冰蟲的酶在接近零度左右仍有活力;但溫度若超過5度,酶便會消化其細胞膜,把冰蟲本身給溶化。冰蟲可達約數公分長,體色有黑、藍、白等。在約清晨及傍晚時會接近冰層表面。以雪水藻類花粉為食。

目前仍不清楚冰蟲如何在堅硬的冰層中建立通道。一些科學家認為冰蟲是以冰床中的超細微縫隙來旅行;一些人則相信冰蟲可以分泌某種化學物質來溶解冰層。

延伸閱讀

  • Hartzell, P. (2003). Glacial Ecology: North Cascades Glacier Macroinvertebrates. Retrieved on Oct. 21, 2005, from: https://web.archive.org/web/20051212000121/http://nichols.edu/departments/Glacier/bio/index.htm
  • Pelto, M. S. (2003). Ice Worms (Mesenchytraeus solifugus) and Their Habitats on North Cascade Glaciers. A study by North Cascade Glacier Climate Project. Retrieved on Sept. 28, 2005, from http://www.nichols.edu/departments/glacier/iceworm.htm
  • Shain, D. H., Carter M. R., Murray, K. P., Maleski, K. A., Smith, N. R., McBride, T. R., et al. (2000). Morphologic Characterization of the Ice Worm Mesenchytraeus solifugus. Journal of Morphology, 246, 192-197.
  • Shain, D. H., Mason, T. A., Farrell, A. H., & Michalewicz, L. A. (2001). Distribution and behavior of ice worms (Mesenchytraeus solifugus) in south-central Alaska. Canadian Journal of Zoology, 79, 10, 1813-1821.

外部連結

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冰蟲: Brief Summary ( Chinese )

provided by wikipedia 中文维基百科

冰蟲是指Mesenchytraeus屬的環節動物的總稱,生活於北極地區的冰層中。

Mesenchytraeus solifugus是最早發現的種類,於1887年在阿拉斯加發現。是地球上極少數能在攝氏0度以下仍能生存的生物。冰蟲的酶在接近零度左右仍有活力;但溫度若超過5度,酶便會消化其細胞膜,把冰蟲本身給溶化。冰蟲可達約數公分長,體色有黑、藍、白等。在約清晨及傍晚時會接近冰層表面。以雪水藻類花粉為食。

目前仍不清楚冰蟲如何在堅硬的冰層中建立通道。一些科學家認為冰蟲是以冰床中的超細微縫隙來旅行;一些人則相信冰蟲可以分泌某種化學物質來溶解冰層。

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