Demosponge

class of sponges (phylum Porifera)

The Demospongiae are the largest class in the phylum Porifera. Their skeletons are made of spicules consisting of fibers of the protein spongin, the mineral silica, or both. Where spicules of silica are present, they have a different shape from those in the otherwise similar glass sponges.

Demospongiae
Barrel sponge (Xestospongia testudinaria)
Scientific classification
Kingdom:
Phylum:
Class:
Demospongiae
Subclasses

Homoscleromorpha
Tetractinomorpha