What types of sponges are used in households? Aquatic Animals Read more from Chapter Aquatic and Land Animal Diversity

Asponge is supported by a skeleton made of hard crystals called spicules, which can be calcareous (made of calcium carbonates, the material found in limestone) or siliceous (made of silica—essentially, glass). Either type of sponge forms into a delicate network, giving the sponge its characteristic “holey-spongy” look.

A type of sponge called the demosponge has siliceous spicules and a network of fibrous proteins called sponging; they are the source of all natural household sponges. These utilitarian sponges are made by soaking the dead sponges in shallow water until all the once living cellular material has decayed, leaving the spongin network behind. Because this process is so labor intensive—and it also depletes the numbers of natural sponges—most sponges now sold for household use are plastic or fiber and have nothing to do with real sponges.