Crumb-of-bread sponge
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Porifera
Class:	Demospongiae
Order:	Suberitida
Family:	Halichondriidae
Genus:	Hymeniacidon
Species:	H. perlevis
Binomial name
Hymeniacidon perlevis (Montagu, 1818)
Synonyms
List Axinella cristagalli Maas, 1894 Halichondria caruncula (Bowerbank, 1858) Halichondria macularis Johnston, 1846 Halichondria sanguinea (Grant, 1826) Hymeniacidon aldousii Bowerbank, 1874 Hymeniacidon aurea (Montagu, 1814) Hymeniacidon caruncula Bowerbank, 1858 Hymeniacidon consimilis Bowerbank, 1866 Hymeniacidon hillieri Bowerbank, 1882 Hymeniacidon mammeata Bowerbank, 1866 Hymeniacidon medius Bowerbank, 1874 Hymeniacidon perleve [lapsus] Hymeniacidon radiosa Bowerbank, 1874 Hymeniacidon sanguinea (Grant, 1826) Hymeniacidon virgulatus Bowerbank, 1882 Hymeniacidon viridans Bowerbank, 1866 Isodictya uniformis Bowerbank, 1866 Polymastia mammeata (Bowerbank, 1866) Raphiodesma simplissima Bowerbank, 1874 Reniera uniformis (Bowerbank, 1866) Spongia aurea Montagu, 1814 Spongia perlevis Montagu, 1814 Spongia sanguinea Grant, 1826 Stylinos uniformis (Bowerbank, 1866) Stylotella simplissima (Bowerbank, 1874) Stylotella uniformis (Bowerbank, 1866) Suberites paludum Schmidt, 1868

The crumb-of-bread sponge (Hymeniacidon perlevis) is a species of sea sponge in the class Demospongiae.

The crumb-of-bread sponge is a thickly encrusting sponge with a glistening bumpy surface. Specimens found intertidally are bright yellow. Specimens from deeper water are darker. The sponge has been found to have a certain scent, it's been described as exploded gunpowder. The oscula are scattered across the surface of the sponge and may be flush with the sponge surface or on raised mounds.^[1] The form of the sponge is variable, depending on its environment. In sheltered areas, branched structures grow from the base. In areas with wave action the surface is convoluted or flat.^[2]

The crumb-of-bread sponge is found in the northern Atlantic Ocean, the Mediterranean Sea and the Pacific Ocean, as well as around the southern African coast from the northern Cape to Port St Johns. It lives from the intertidal zone in tide pools to a maximum depth of about 15 meters (about 50 feet).