''Agelas dispar'' is a

species In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate s ...

demosponge Demosponges (Demospongiae) are the most diverse class in the phylum Porifera. They include 76.2% of all species of sponges with nearly 8,800 species worldwide (World Porifera Database). They are sponges with a soft body that covers a har ...

in the family Agelasidae. It lives on shallow-water

reef A reef is a ridge or shoal of rock, coral or similar relatively stable material, lying beneath the surface of a natural body of water. Many reefs result from natural, abiotic processes— deposition of sand, wave erosion planing down rock out ...

s in the

Caribbean Sea The Caribbean Sea ( es, Mar Caribe; french: Mer des Caraïbes; ht, Lanmè Karayib; jam, Kiaribiyan Sii; nl, Caraïbische Zee; pap, Laman Karibe) is a sea of the Atlantic Ocean in the tropics of the Western Hemisphere. It is bounded by Mexico ...

and around the West Indies.

Taxonomy

''Agelas dispar'' is the

type species In zoological nomenclature, a type species (''species typica'') is the species name with which the name of a genus or subgenus is considered to be permanently taxonomically associated, i.e., the species that contains the biological type specimen ...

of the

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

and was first described in 1864 by the French naturalist

Édouard Placide Duchassaing de Fontbressin Édouard Placide Duchassaing de Fontbressin (1819 in Moule, Guadeloupe – 1873 in Périgueux) was a French naturalist. He is noted for his work in botany and spongiology. A native of Guadeloupe, he studied zoology, geology and medicine in ...

and the Italian naturalist

Giovanni Michelotti Giovanni Michelotti (6 October 1921 – 23 January 1980) was one of the most prolific designers of sports cars in the 20th century. His notable contributions were for Ferrari, Lancia, Maserati and Triumph marques. He was also associated with ...

. They deposited the

holotype A holotype is a single physical example (or illustration) of an organism, known to have been used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of several ...

in Amsterdam. In 1932, the zoologists M. Burton and H.S. Rao, unaware that the holotype was still in existence, deposited a

neotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the ...

in the Natural History Museum in London, but this specimen has since disappeared.

Description

''Agelas dispar'' forms massive irregularly-shaped, sometimes bulbous mounds or may be encrusting. It can grow to as much as across. The consistency is spongy but firm; the surface is smooth with many exhalent pores of irregular shape and size, often in shallow pits. The colour externally is pinkish-brown, reddish-brown or deep brown. Internally there are large cavities, many primary canals across and narrow secondary canals. There is a fibrous, tightly-meshed skeleton made of

spongin Spongin, a modified type of collagen protein, forms the fibrous skeleton of most organisms among the phylum Porifera, the sponges. It is secreted by sponge cells known as spongocytes. Spongin gives a sponge its flexibility. True spongin is found ...

with ascending and tangential fibres. The

spicules Spicules are any of various small needle-like anatomical structures occurring in organisms Spicule may also refer to: *Spicule (sponge), small skeletal elements of sea sponges *Spicule (nematode), reproductive structures found in male nematodes ( ...

consist of bundles of acanthostyles (one end blunt, one end pointed and covered with 7 to 12 whorls of spines).

Distribution

''Agelas dispar'' is found in the

and around the West Indies; its preferred habitat is shallow-water reefs.

References

{{Taxonbar, from=Q2458488 Agelasida Fauna of the Atlantic Ocean Fauna of the Caribbean Sponges described in 1870