The Muscular System of the demosponge: Demospongiae Pachataxa
The demosponge is the largest class in the phylum Prorifera. Most are marine dwellers but some live in freshwater environments. Some are even brightly colored. Demosponge's do not have muscles as they are stationary in the water relying on water current to move. To find out more about Demosponge's, check this website:
http://www.ucmp.berkeley.edu/porifera/demospongia.html
http://www.ucmp.berkeley.edu/porifera/demospongia.html