Demosponge

Barrel Sponge
Class: Demospongiae
Order: Haplosclerida
Species: Xestospongia testudinaria

The Demosponge class is the largest class in the phylum Porifera. It includes 81% of all species of sea sponges. Its kingdom is Animalia,  its phylum is Porifera, and its class is the Demosponge. The Demosponge class reproduces both sexually and asexually. They have skeletons made of fibers consisting of the protein spongin or the mineral silica, or both. Spongin gives the Demosponge its softness and absorbency. The first Demosponges appeared in the Precambrian era at the end of the "Snowball Earth" period. Demosponges can be used for bath sponges, which are either harvested or grown commercially before being bleached and sold. Sponges are sessile, meaning they have no symmetry and they have cells that work together to filter feed.

https://en.wikipedia.org/wiki/Demosponge