Coelomate animals or Coelomata (also known as eucoelomates – "true coelom") have a body cavity called a coelom with a complete lining called peritoneum derived from mesoderm (one of the three primary tissue layers). ... Acoelomate animals, like flatworms, have no body cavity at all.

Which coelomates contain true coelom?

The animals which possess true coelom are called eucoelomates or coelomates. The true coelom is a body cavity which arises as a cavity in embryonic mesoderm. It is present in • Annelida, Arthropoda, Mollusca (Schizocoelom), Echinodermata and Chordata (Enterocoelom).

What is the difference between coelom and Acoelomate?

The main difference between coelomate and acoelomate body plans are that coelomates have a true coelom, which is a fluid-filled body cavity completely lined by tissue which is derived from mesoderm. ... Acoelomates, though, lack a cavity between the digestive tract and the outer body wall.