Identify the characteristic of acoelomates.

Acoelomates do not have a fluid-filled space between their body wall and alimentary canal. Thus, their internal organs are not protected from external crushing forces. Acoelomates do have some disadvantages as they do not have coelom to diffuse metabolites and gases. But most acoelomates have a smaller body surface, and hence this use of coelom is negligible. Also, the absence of body cavities does not signify the absence of fluid currents in the body.