The pseudocoelom is a fluid-filled body cavity lying inside the external body wall of the nematode that bathes the internal organs, including the alimentary system and the reproductive system (PeriFIG 1). ... PeriFIG 1: Pseudocoelom (body cavity).

Do pseudocoelomates have a body cavity?

Pseudocoelomate metazoans have a fluid-filled body cavity, the pseudocoelom, which, unlike a true coelom, does not have a cellular peritoneal lining. Most of the pseudocoelomates (e.g., the classes Nematoda and Rotifera) are small and none possess an independent vascular system.

Why is the body cavity known as a pseudocoelom?

Some animals possess a “false” coelom called a pseudocoelom. These animals are known as pseudocoelomates. A pseudocoelom is a body cavity that lies between mesodermal and endodermal tissue and is, therefore, not completely surrounded by mesodermal tissue.