Porifera

This article or section should be merged with Sponge.

The phylum Porifera (from Latin porus "pore" and ferre "to bear") consists of primitive multicellular aquatic animals commonly referred to as sponges. There are approximately 5,000 distinct species of sponges, which can be found attached to surfaces anywhere from the intertidal zone to as deep as 8,500 m (29,000 feet) or further. Adult sponges do not show significant movement of body parts and do not have a definite nervous system. There are three classes within the phylum Porifera; these are the Calcispongiae, Hexactinellida and Demospongiae. About one-fifth of known sponges fall within Calcispongiae and Hexactinellida; the remainder are classified as Demospongiae. Sponges may reproduce sexually and asexually.