Antedon Temporal range: | |
---|---|
Antedon mediterranea | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Crinoidea |
Order: | Comatulida |
Family: | Antedonidae |
Subfamily: | Antedoninae |
Genus: | Antedon de Freminville, 1811 [1] |
Species | |
See text |
Antedon is a genus of sessile, stemless crinoids. The genus first appeared in the fossil record in the Cretaceous period. [2]
Members of this genus have no stems but have five pairs of feathery arms arising from a central concave disc. There are a number of cirri or unbranched appendages on a low, cone-shaped dorsal ossicle, a bone-like structure in the centre of the disc. The mouth and the ambulacral grooves are also on the upper surface. Clawed cirri on the lower surface provide temporary attachment to the substrate. [3] There is great variability in the morphological features in Antedonids found in different habitats and the main distinguishing feature among the species is the number of cirri. [4]
The following species are recognised in the World Register of Marine Species: [1]
Crinoids are marine invertebrates that make up the class Crinoidea. Crinoids that remain attached to the sea floor by a stalk in their adult form are commonly called sea lilies, while the unstalked forms, called feather stars or comatulids, are members of the largest crinoid order, Comatulida. Crinoids are echinoderms in the phylum Echinodermata, which also includes the starfish, brittle stars, sea urchins and sea cucumbers. They live in both shallow water and in depths as great as 9,000 meters (30,000 ft).
Starfish or sea stars are star-shaped echinoderms belonging to the class Asteroidea. Common usage frequently finds these names being also applied to ophiuroids, which are correctly referred to as brittle stars or basket stars. Starfish are also known as asteroids due to being in the class Asteroidea. About 1,900 species of starfish live on the seabed in all the world's oceans, from warm, tropical zones to frigid, polar regions. They are found from the intertidal zone down to abyssal depths, at 6,000 m (20,000 ft) below the surface.
The Myzostomida or Myzostomatida are an order of small marine worms, which are parasitic on echinoderms, mostly crinoids. These highly unusual and diverse annelids were first discovered by Friedrich Sigismund Leuckart in 1827.
The Ophidiasteridae are a family of sea stars with about 30 genera. Occurring both in the Indo-Pacific and Atlantic Oceans, ophidiasterids are greatest in diversity in the Indo-Pacific. Many of the genera in this family exhibit brilliant colors and patterns, which sometimes can be attributed to aposematism and crypsis to protect themselves from predators. Some ophidiasterids possess remarkable powers of regeneration, enabling them to either reproduce asexually or to survive serious damage made by predators or forces of nature. Some species belonging to Linckia, Ophidiaster and Phataria shed single arms that regenerate the disc and the remaining rays to form a complete individual. Some of these also reproduce asexually by parthenogenesis.
Articulata are a subclass or superorder within the class Crinoidea, including all living crinoid species. They are commonly known as sea lilies or feather stars. The Articulata are differentiated from the extinct subclasses by their lack of an anal plate in the adult stage and the presence of an entoneural system. Articulata first appeared in the fossil record during the Triassic period although other, now extinct crinoid groups, originated in the Ordovician.
Whale barnacles are species of acorn barnacle that belong to the family Coronulidae. They typically attach to baleen whales, and sometimes settle on toothed whales. The whale barnacles diverged from the turtle barnacles about three million years ago.
Comasteridae is a family of crinoids.
The Brisingids are deep-sea-dwelling starfish in the order Brisingida.
The Asterozoa are a subphylum in the phylum Echinodermata. Characteristics include a star-shaped body and radially divergent axes of symmetry. The subphylum includes the class Asteroidea, the class Ophiuroidea, and the extinct order Somasteroidea.
Luidia is a genus of starfish in the family Luidiidae in which it is the only genus. Species of the family have a cosmopolitan distribution.
Antedonidae is a family of crinoids or feather stars in the phylum Echinodermata. Members of the family are unstalked and have ten feathery arms. They can move about freely and have clawed cirri to attach them temporarily to structures.
Antedon bifida is a species of crinoid in the family Antedonidae commonly known as the rosy feather star. It is found in north west Europe.
Antedon petasus is a marine invertebrate, a species of crinoid or feather star in the family Antedonidae. It is found around the coasts of north west Europe.
Metacrinus is a genus of stalked crinoids in the family Isselicrinidae. Members of this genus live on hard surfaces in deeper parts of the ocean. The genus has extant species and is also represented in the fossil record. Members of the genus grow to a maximum height of 60 centimetres (24 in) and are found in the eastern Pacific Ocean from Japan to Australia.
Antedon mediterranea is a species of stalkless crinoid in the family Antedonidae, commonly known as the Mediterranean feather star. It is found on the seabed at moderate depths in the Mediterranean Sea. It is a filter feeder and captures plankton with its long feathery arms.
Bourgueticrinida is an order of crinoids that typically live deep in the ocean. Members of this order are attached to the seabed by a slender stalk and are known as sea lilies. While other groups of crinoids flourished during the Permian, bourgueticrinids along with other extant orders did not appear until the Triassic, following a mass extinction event in which nearly all crinoids died out.
Leptometra is a genus of free-swimming, stemless crinoids.
Florometra serratissima is a species of crinoid or feather star in the family Antedonidae. It is found off the Pacific coast of North America, usually in deep water.
Aporometridae is a monotypic family of crinoids, the only genus being Aporometra, which contains three species, all endemic to the seas around Australia.
Notocrinidae is a monotypic family of crinoids, the only genus being Notocrinus, which contains two species, both endemic to the seas around Antarctica.