Sea sponges are animals that live on the ocean floor. After human beings harvest and dry them, the sponges serve as the household tool many people use to bathe and wash dishes and cars, among other items.
Sponges, which have neither brains nor central nervous systems, attach themselves to rocks and other solid objects on the ocean floor, where they remain permanently, according to Mediterranean Natural Sponges, an Australia-based supplier of natural sponges. The ancient animal is considered by scientists to have a highly efficient design. Sponges feed by filtering organic particles and plankton through pores along the surfaces of their bodies. This is also how they obtain oxygen. While there are roughly 5,000 sponge species in the world, only seven species are considered commercially feasible to harvest.
According to the Oceanic Research Group, a nonprofit organization committed to the conservation of oceans and marine life through education, there are two primary types of sponge. The encrusted type tends to cover a rock or other solid object in a fashion similar to moss. Free-standing sponges, on the other hand, grow into a variety of shapes. Free-standing sponges are capable of growing to fairly large sizes, with the barrel sponge sometimes becoming larger than a human being.