Echinidae is a

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

sea urchin Sea urchins () are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to . The spherical, hard shells (tests) of ...

s in the order

Echinoida Echinoida is an order of sea urchins in the class Echinoidea. They are distinguished from other sea urchins by simultaneously possessing both an un-sculpted test and a feeding lantern with large plates fused across the top of each pyramid. Tax ...

. Members of the family are found in the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

and the

Antarctic The Antarctic ( or , American English also or ; commonly ) is a polar region around Earth's South Pole, opposite the Arctic region around the North Pole. The Antarctic comprises the continent of Antarctica, the Kerguelen Plateau and other ...

.Family Echinidae Gray, 1825.
The Echinoid Directory. Retrieved 2011-08-28.

Characteristics

Members of the family Echinidae are characterized by having trigeminate ambulacra (quadrigeminate in one genus) with pairs of

tube feet Tube feet (technically podia) are small active tubular projections on the oral face of an echinoderm, whether the arms of a starfish, or the undersides of sea urchins, sand dollars and sea cucumbers; they are more discreet though present on britt ...

pores arranged either as vertical arcs or as a dense band. The ambulacral plates are compound. The tubercles are imperforate and do not have crenulate edges. There are few tubercles on the interambulacral plates. The buccal notches are reduced in size and, their most significant distinguishing feature, the

pedicellariae A pedicellaria (plural: pedicellariae) is a small wrench- or claw-shaped appendage with movable jaws, called valves, commonly found on echinoderms (phylum Echinodermata), particularly in sea stars (class Asteroidea) and sea urchins (class Echinoi ...

are globiferous and have one or two pairs of lateral teeth on the narrow tubular blades.True Sea-urchins (Family Echinidae)
Marine Species Identification Portal. Retrieved 2011-08-28.

Genera

According to the

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

(WoRMS), the following

genera Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nomenclat ...

are included in the family: *''

Dermechinus ''Dermechinus'' is a genus of sea urchin in the family Echinidae found in deep water in the southern Indian, Pacific and Atlantic Oceans. It is monotypic, with ''Dermechinus horridus'', sometimes called the cactus urchin, being the only specie ...

'' ( Mortensen, 1942) -- 1 species *'' Echinus''

Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...

1758 Events January–March * January 1 – Swedish biologist Carl Linnaeus (Carl von Linné) publishes in Stockholm the first volume (''Animalia'') of the 10th edition of Systema Naturae, 10th edition of ''Systema Naturae'', the sta ...

-- 9 species *'' Gracilechinus'' ( Fell & Pawson, 1966) -- 8 species *'' Polyechinus'' ( Mortensen, 1942) -- 1 species *'' Sterechinus'' (

Koehler Koehler is a transliteration of the German surname Köhler, referring to a man making charcoal from wood. Notable people with the surname include: * Ana Luiza Koehler (born 1977), Brazilian comics artist and architect. *Arthur Koehler (1885– ...

, 1901) -- 6 species *'' Atactus''

Pomel Nicolas Auguste Pomel (20 September 1821 – 2 August 1898) was a French geologist, paleontologist and botanist. He worked as a mines engineer in Algeria and became a specialist in north African vertebrate fossils. He was Senator of Algeria for Ora ...

, 1883 † (''nomen dubium'') *'' Stirechinus'' ( Desor, 1856) † Image:Expl1825 - Flickr - NOAA Photo Library.jpg, '' Dermechinus horridus'' Image:Echinus esculentus - Carantec.jpg, ''

Echinus esculentus ''Echinus esculentus'', the European edible sea urchin or common sea urchin, is a species of marine invertebrate in the Echinidae family. It is found in coastal areas of western Europe down to a depth of . It is considered "Near threatened" in t ...

'' Image:Gracilechinus acutus.JPG, ''

Gracilechinus acutus ''Gracilechinus acutus'' is a species of sea urchin in the family Echinidae, commonly known as the white sea urchin. It is an omnivore and feeds on algae and small invertebrate Invertebrates are a paraphyletic group of animals that neither p ...

'' Image:Sea urchins, Sterechinus neumayeri.jpg, ''

Sterechinus neumayeri ''Sterechinus neumayeri'', the Antarctic sea urchin, is a species of sea urchin in the family Echinidae. It is found living on the seabed in the waters around Antarctica. It has been used as a model organism in the fields of reproductive biolo ...

References

{{Taxonbar, from=Q528635 Extant Miocene first appearances