Porifera- The phylum Porifera are better known as sponges. They are multicellular organisms, whose bodies are full of pores and challens that allow water to flow through them. Sponges live of the water flowing through them because they don't have a nervous, digestive, or circulatory system. The constant water flow supplies them with food and oxygen. Most sponges live in clear, clam water and are usually found on rocks on rooted into to sand.
Sponges do not have a excretory system. They clean out waste by using the water that flows through them. The food obtained from water is delivered to cells that eat it. Then the waste and carbon dioxide is realized when the water flows through the cells. The Archeocytes usually dump the waste into the outgoing water current, however some species incorporate the waste into their skeletons.