Heligmosomoides polygyrus 3340565 194749029 2008-02-28T21:46:26Z Eubot 231599 Removed taxobox colour. See [[User:Eubot/Removing colours from taxoboxen]]. {{Taxobox | name = ''Heligmosomoides polygyrus'' | regnum = [[Animalia]] | phylum = [[Nematoda]] | classis = [[Chromadorea]] | ordo = [[Rhabditida]] | familia = [[Heligmosomatidae]] | genus = ''[[Heligmosomoides]]'' | species = '''''H. polygyrus''''' | binomial = ''Heligmosomoides polygyrus'' }} '''''Heligmosomoides polygyrus''''' is a common [[nematode]] found in the duodenum and small intestine of [[woodmouse|woodmice]] and other [[rodents]]. They are 5-20mm in length and bright red due to the pigmentation of their tissues. They are usually heavily coiled, with the female having 12-15 coils and the male 8-12. The male can be distinguished from the female by a prominent [[copulatory bursa]] and two long, thin [[spicule]]s at the posterior end. They have a direct [[Biological life cycle|life cycle]]. The eggs pass out with the [[faeces]] of the [[host (biology)|host]] into the environment. After 2 days they hatch as [[larvae]] which are about 300μm in length. The larvae moult 3 days later but retain the shed cuticle for protection. It is at this point they become infective. The larvae shed the outer protective sheath after they are eaten by a suitable host. The larvae then penetrate the [[submucosa]] of the duodenum where they under go 2 further molts. About 7 days later the male and female adult worms emerge into the [[lumen]] of the [[duodenum]]. They attach to the epithelial layer of the duodenum where they feed off the contents of the gut. The adult worms mate and eggs are shed in the feces. The complete life cycle from egg to egg takes a minimum of 15 days, and the female worms will live inside their host for 8 months. These worms often form [[cyst]]s in the wall of the intestine. These cysts often become infected with bacteria, but it is not yet known if these are harmful to the host. This is organism is used to model human helminth infection in laboriory mice. [[Category:Nematodes|Heligmosomoides polygyrus]]