Editing Ascaris lumbricoides (section)

==Morphology and anatomy==
[[File:Ascaris lumbricoides4.jpg|right|thumb|Fertile egg as can be seen in a microscope]]
[[File:Ascaris lumbricoides.jpg|right|thumb|Fertile egg in human faeces (detail)]]
[[File:Ascaris lumbricoides non-fertile egg.jpg|right|thumb|Infertile egg]]
''Ascaris lumbricoides'' is characterized by its great size. Males are {{Convert|2|–|4|mm|in|abbr=on|sigfig=1}} in diameter and {{Convert|15|–|31|cm|in|abbr=on|sigfig=2}} long. The male's posterior end is curved ventrally and has a bluntly pointed tail. Females are {{Convert|3|–|6|mm|in|abbr=on|sigfig=1}} wide and {{Convert|20|–|49|cm|in|abbr=on|sigfig=2}} long. The [[vulva (disambiguation)|vulva]] is located in the anterior end and accounts for about one-third of its body length. [[uterus|Uteri]] may contain up to 27 million eggs at a time, with 200,000 being laid per day. Fertilized eggs are oval to round in shape and are {{Convert|45|–|75|μm|in|abbr=on}} long and {{Convert|35|–|50|μm|in|abbr=on}} wide with a thick outer shell. Unfertilized eggs measure {{Convert|88|–|94|μm|in|abbr=on}} long and {{Convert|44|μm|in|abbr=on}} wide.<ref name="Roberts">Roberts, Larry S.; Janovy, John Jr. ''Foundations of Parasitology'', Eighth Edition. United States: McGraw-Hill, 2009{{page needed|date=August 2015}}</ref>

Anatomically, the digestive tract is complete with prominent muscular [[pharynx]]. [[Respiration (physiology)|Respiration]] is by simple diffusion across body wall. The nervous system consists of a [[nerve ring]] and many longitudinal nerve cords. They are dioecious and have separate reproductive systems consisting of thread like gonads and genital ducts that open outside by apertures. Fertilization is internal and [[Embryo|development]] is mostly indirect. [[Sexual dimorphism]] is well marked. Externally, males are much shorter than females and males also have a curved posterior end, unlike females. Internally, in males, all the digestive, reproductive systems open in a common chamber- cloaca whereas in females, there is a separate anus for digestive tract and female genital pore for female reproductive system.{{fact|date=March 2025}}