Introduction

Poriferans (Latin porus, "pore"; ferre, "to bear"), the sponges, are distributed worldwide from the intertidal zone to deep ocean waters, including the Arctic and Antarctic. They are divided among three classes: Demospongiae, Calcarea, and Hexactinellida. Until 1765, sponges were classified as plants due to their sessile nature and lack of complexity!

Among the 5000 living species, only two have been used commercially as bath sponges (Spongia and Hippospongia). A wild sponge requires 5 years of growth to reach a marketable size (12.5 cm), after which time it is killed, dried, and kneaded. This process yields the spicule-free spongin skeleton that can hold up to 35 times its weight in water.