What is the definition of "Porifera"?

Porifera, which means pore bearer, is a phylum that includes the organisms known as sponges. Sponges consist of a jelly-like substance between two layers of cells and are found in freshwater and marine habitats.

Sponges draw in water through the pores and filter out the food. The water is then pumped out of the body through larger openings. Sponges do not have organ systems and depend on a constant flow of water for food, oxygen and elimination of waste. Some cells can move around and change into other types of cells. Since sponges have no body symmetry, they can change the shape of their bodies.