<Li> Nemertea, traditionally viewed as acoelomates </Li> <P> For others, the coelomate phyla excludes Nemertea but also comprises Entoprocta, Pentastoma, Pogonophora (i.e., from tiny sessile aquatic animals to great whales and everything in between). </P> <P> In some protostomes, the embryonic blastocoele persists as a body cavity . These protostomes have a fluid filled main body cavity unlined or partially lined with tissue derived from mesoderm . </P> <P> This fluid - filled space surrounding the internal organs serves several functions like distribution of nutrients and removal of waste or supporting the body as a hydrostatic skeleton . </P>

Define coelom. how is the coelom related to the hydrostatic skeleton