View source for Nematode Worms (Caenorhabditis Elegans)

[[File:Adult_Caenorhabditis_elegans.jpg|alt=|right|frameless]]
'''''Caenorhabditis elegans''''' is a free-living transparent nematode worm about 1&nbsp;mm in length<ref>
{{cite book | last = Wood | first = WB | year = 1988 | title = The Nematode ''Caenorhabditis elegans'' | page = 1 | publisher = [[Cold Spring Harbor Laboratory Press]] | isbn = 978-0-87969-433-3 }}</ref> that lives in temperate soil environments. It is the type species of its genus.<ref>{{cite journal |doi=10.1111/j.1439-0469.1996.tb00827.x |title=Phylogeny of ''Rhabditis'' subgenus ''Caenorhabditis'' (Rhabditidae, Nematoda) |journal=Journal of Zoological Systematics and Evolutionary Research |volume=34 |issue=4 |pages=217–233 |year=2009 | vauthors = Sudhaus W, Kiontke K }}</ref> The name is a blend of the Greek ''caeno-'' (recent), ''rhabditis'' (rod-like)<ref>καινός (caenos) = new, recent; ῥάβδος (rhabdos) = rod, wand.</ref> and Latin ''elegans'' (elegant). In 1900, Maupas initially named it ''Rhabditides elegans.'' Osche placed it in the subgenus ''Caenorhabditis'' in 1952, and in 1955, Dougherty raised ''Caenorhabditis'' to the status of genus.<ref>
{{cite web
 |last=Ferris
 |first=H
 |date=30 November 2013
 |title=''Caenorhabditis elegans''
 |url=http://plpnemweb.ucdavis.edu/nemaplex/Taxadata/G900S2.htm
 |publisher=[[University of California, Davis]]
 |access-date=2013-11-19
 |url-status=dead
 |archive-url=https://web.archive.org/web/20131209003325/http://plpnemweb.ucdavis.edu/nemaplex/taxadata/G900S2.htm
 |archive-date=9 December 2013
 }}</ref>

''C. elegans'' is an unsegmented pseudocoelomate and lacks respiratory or circulatory systems.<ref>{{cite journal| vauthors = Wallace RL, Ricci C, Melone G | title =A cladistic analysis of pseudocoelomate (aschelminth) morphology.|journal=Invertebrate Biology| volume =115| issue =2|date=1996|pages=104–112| doi =10.2307/3227041| jstor =3227041}}</ref> Most of these nematodes are hermaphrodites and a few are males.<ref>{{Cite web | url = http://www.wormbook.org/chapters/www_introsexdetermination/introsexdetermination.html |title=Introduction to sex determination|website=www.wormbook.org|access-date=2017-03-15}}</ref> Males have specialized tails for mating that include spicules.

In 1963, Sydney Brenner proposed research into ''C. elegans,'' primarily in the area of neuronal development. In 1974, he began research into the molecular and developmental biology of ''C. elegans'', which has since been extensively used as a [[Model Organisms|model organism]].{{pmid|4366476}} It was the first multicellular organism to have its whole genome sequenced, and in 2019 it was the first organism to have its connectome (neuronal "wiring diagram") completed.{{pmid|22462104}}{{pmid|23801597}}<ref>{{cite magazine  |last=Jabr |first=Ferris | name-list-style = vanc |date=2012-10-02 |title=The Connectome Debate: Is Mapping the Mind of a Worm Worth It? |url=https://www.scientificamerican.com/article/c-elegans-connectome/ |magazine=Scientific American |access-date=2014-01-18}}</ref>