Phylum Porifera

Phylum Porifera Sponges are the simplest animals Radially symmetrical Acoelomate Body resembles a perforated sac. Has inner cavity called spongocoel Has large opening called osculum Lining body are cells flagellated cells called choanocytes These cells beat to produce a flow of H20 into the sponge through pores in through the body wall, and out through the osculum. Body wall is composed of many elements Mesohyl - gelatenous material Amoebocytes Motile cells which perform many functions Capture, digest and transport food Create tough structural fibers of the body wall called spicules.

A Typical Sponge

Sponges