''Agelas dispar'' is a

species A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...

demosponge Demosponges or common sponges are sponges of the class Demospongiae (from + ), the most diverse group in the phylum Porifera which include greater than 90% of all extant sponges with nearly 8,800 species A species () is often de ...

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 component, abiotic (non-living) processes such as deposition (geol ...

s in the

Caribbean Sea The Caribbean Sea is a sea of the Atlantic Ocean, North Atlantic Ocean in the tropics of the Western Hemisphere, located south of the Gulf of Mexico and southwest of the Sargasso Sea. It is bounded by the Greater Antilles to the north from Cuba ...

and around the West Indies.

Taxonomy

''Agelas dispar'' is the

type species In International_Code_of_Zoological_Nomenclature, 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 spe ...

of the

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

and was first described in 1864 by the French naturalist

Édouard Placide Duchassaing de Fontbressin Édouard Placide Duchassaing de Fontbressin (c. 1819 in Le Moule, 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 med ...

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 Motor Company, Triumph marques. He was ...

. They deposited the

holotype A holotype (Latin: ''holotypus'') is a single physical example (or illustration) of an organism used when the species (or lower-ranked taxon) was formally described. It is either the single such physical example (or illustration) or one of s ...

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 associated. In other words, a type is an example that serves to anchor or centralizes ...

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 Sponges of the Atlantic Ocean Fauna of the Caribbean Sponges of Brazil Sponges described in 1870