Panagrolaimus detritophagus is a terrestrial free-living nematode (roundworm). It has been reported in California, South America and Europe.[2] It is the type species of the genus Panagrolaimus.[3] In 2018, it, along with another nematode species (Plectus parvus) became the first multicellular organism to be thawed back into a living state after prolonged cryopreservation.[4][5] Pleistocene permafrost was obtained from the Kolyma River lowland, and thawed. The worms moved and ate after being thawed. They had been frozen for 30–40 thousand years, based on the age of that deposit.[4][5][6]
| Panagrolaimus detritophagus | |
|---|---|
Scientific classification 
| |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Nematoda |
| Class: | Secernentea |
| Order: | Tylenchida |
| Family: | Panagrolaimidae |
| Genus: | Panagrolaimus |
| Species: | P. detritophagus
|
| Binomial name | |
| Panagrolaimus detritophagus | |
Ecology
editThis species is non-parasitic. It decomposes soil organic matter with the aid of symbiotic bacteria.[2] As such it is a decomposer. It is also involved in nitrogen mineralization. This species is considered an enrichment opportunist.[7] That means that this is a cp-1 ("colonizer") nematode, like many Panagrolaimidae species.[8] Enrichment opportunists are loosely comparable to r-strategists. They multiply quickly after an organic enrichment event, and then their population rapidly declines when nutrients run out.[9] Organic enrichment is the rapid addition of a large amount of organic nutrients, for example due to a pollution event.[10]
Anatomy
editAdult females have been measured to be approximately 740 micrometers long and 33.5 micrometers wide, with a mass of approximately half a microgram.[7] Males and females have been collected.[2] All specimens have a short, cylinder-shaped stoma and a valve in the postcorpus. This species lacks caudal alae. Males have spicules. Females have a single ovary which is reflexed and prodelphic. The spermatheca is offset. This species is described as very active and fast-moving.[2]
References
edit- ^ "WoRMS – World Register of Marine Species – Panagrolaimus detritophagus Fuchs, 1930". Marinespecies.org. Retrieved 1 September 2018.
- ^ a b c d "Panagrolaimus detritophagus". Nemaplex.ucdavis.edu. Retrieved 1 September 2018.
- ^ Mullin, Peter. "Panagrolaimus sp". Nematode.unl.edu. Retrieved 1 September 2018.
- ^ a b "Worms Frozen for 42,000 Years in Siberian Permafrost Wriggle to Life". Livescience.com. Retrieved 1 September 2018.
- ^ a b Shatilovich, A. V.; Tchesunov, A. V.; Neretina, T. V.; Grabarnik, I. P.; Gubin, S. V.; Vishnivetskaya, T. A.; Onstott, T. C.; Rivkina, E. M. (1 May 2018). "Viable Nematodes from Late Pleistocene Permafrost of the Kolyma River Lowland". Doklady Biological Sciences. 480 (1): 100–102. doi:10.1134/s0012496618030079. PMID 30009350.
- ^ "Siberian Worms Survived More Than 30,000 Years Stuck in Permafrost". Atlasobscura.com. 30 July 2018. Retrieved 1 September 2018.
- ^ a b "Nematode Ecophysiological Parameters – species level". Nemaplex. University of California. Retrieved 1 September 2018.
- ^ Bongers, Tom (1990). "The maturity index: an ecological measure of environmental disturbance based on nematode species composition". Oecologia. 83 (1): 14–19. doi:10.1007/bf00324627.
- ^ Ferris, Howard; Bongers, Tom (1 March 2006). "Nematode Indicators of Organic Enrichment". Journal of Nematology. 38 (1): 3–12. PMC 2586436. PMID 19259424.
- ^ Hellawell, J. M. (1986). "The effects of organic enrichment". Biological Indicators of Freshwater Pollution and Environmental Management. pp. 155–211. doi:10.1007/978-94-009-4315-5_6.