The sponge you use to scrub with in the bathtub is most certainly not living. It is no more alive than a human skeleton. In fact, the sponge that you buy at the market is actually the skeleton of the sponge animal. When fully clothed with flesh and skin, this fellow is alive, though he looks more like a living plant than a living animal.

Most sponges are marine animals who spend their lives squatting on the floor of some warmish sea. They look for all the world like chubby lettuces and small round shrubs. Usually there are a lot of them together and you could easily mistake them for an underwater vegetable garden. Some are drabbish grey, some are rosy red, yellow, orange, violet or even black.

There are some 3, 000 spongy members of the animal phylum Porifera, ranging in size from a fraction of an inch to six feet. There trumpet shaped sponges, basket shaped, finger shaped and dome shaped sponge. All have tough, leathery skins stretched tight over cushiony layers of fleshy tissue. All have skins riddled with tiny pores, which is why the name of their phylum means the pore bearers.

Water, bearing oxygen and scraps of food, passes into the body of a sponge where it circulates through a network of connecting canals. In the center of the fleshy tissue we find the skeleton of the sponge, which is also riddled with tubes. The skeleton which supports the soft body tissues may be made of hard, glassy material, soft, rubbery material or a mixture of both   depending on the kind of sponge.

Tho bathtub sponge is a dome shaped fellow who enjoys life in warm surroundings, such as the Mediterranean Sea.

Its skeleton is made entirely of soft, rather elastic sponging – though this cannot be seen while the animal is alive. Other spongin sponges are found off the coast of Florida and in the warm waters of the Gulf of Mexico.

Sponge fishing calls for skin diving, for the fisherman must gather his catch from the floor of the sea. The sponges, brought to the surface in baskets, are soggy masses covered with thick, dark skins. When cut apart, the inside of a fresh sponge looks like raw liver. All the flesh and skin must be removed before the strange animals are ready for market.

The first job of washing and cleaning is done as soon as the sponges are brought on deck. Then they are strung up to dry aid given time for their fleshy material to decay. The spongy skeletons are then taken ashore, cleaned and sorted.