Question

How do you account for the origin of perivisceral space in the body of a nematode and and an annelid?

Answer 1

Large nematodes do have originated a perivisceral space, between the digestive tract and body wall. But the gut is often lined only by the basal laminate of the epithelial. Mesodermal cells occur on the gut, but there is not a complete Mesodermal tissue sheath. The perivisceral cavity in nematodes is regarded as pseudocoel. it the internal cavity of an organism that develops in the developmental stages and give coelom.While in annelid a true coelom is present, which is a body cavity between digestive tube and external body wall that is lined with Mesodermal tissue.