Sponges are the simplest form of multi-cellular animals. A sponge is a bottom-dwelling creature which attaches itself to something solid in a place where it can find enough food to grow. The scientific name for sponges is "Porifera," which translates into "pore-bearing."
A sponge exists by pumping water through its body. A sponge is covered with tiny pores which lead internally to a system of canals and eventually out to one or more larger holes. These canals exist to move water through the sponge's body. Lining these canals are special collar cells. The collar cells force water through the sponge which brings oxygen and nutrients while removing carbon dioxide and waste. The collar cells are how sponges feed. The water brings with it bacteria and other organisms which the cells capture and filter out.
How Do Sponges Reproduce?
The Two Types of Sponges
Encrusting sponges are similar to moss because they tend to cover the surfaces of rocks.Because of their strange and large shapes, free standing sponges are best known to people. The barrel sponge, a tropical sponge, can grow large enough to fit a person inside of it. Tube sponges are well known for very varied coloration.