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Asteroidea
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 below the surface. Starfish are marine invertebrates. They typically have a central disc and usually five arms, though some species have a larger number of arms. The aboral or upper surface may be smooth, granular or spiny, and is covered with overlapping plates. Many species are brightly coloured in various shades of red or orange, while others are blue, grey or brown. Starfish have tube feet operated by a hydraulic system and a mouth at the centre of the oral or lower surfa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brisingida
The Brisingids are deep-sea-dwelling starfish in the order Brisingida. Description These starfish have between 6 and 16 long, attenuated arms which they use for suspension feeding. Other characteristics include a single series of marginals, a fused ring of disc plates, the lack of actinal plates, a spool-like ambulacral column, reduced abactinal plates, and crossed pedicellariae. They are 40 times the size of disk radius and have 7–20 flexible spiny arms. Distribution Brisingida occur in a number of deep-sea locations, particularly in the Caribbean and New Zealand New Zealand () is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and List of islands of New Zealand, over 600 smaller islands. It is the List of isla .... This type of species are found of varying size especially in the eastern Pacific Ocean at a depth of 1,820–2,418 m. Taxonomy The Brisingida contain two fam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Valvatida
The Valvatida are an order of starfish in the class Asteroidea, which contains 695 species in 172 genera in 17 families. Description The order encompasses both tiny species, which are only a few millimetres in diameter, like those in the genus '' Asterina'', and species which can reach up to 75 cm, such as species in the genus '' Thromidia''. Almost all species in this order have five arms with tube feet. This order is primarily identified by the presence of conspicuous marginal ossicles, which characterize most of the species. Most members of this order have five arms and two rows of tube feet with suckers. Some species have paxillae and in some, the main pedicellariae are clamp-like and recessed into the skeletal plates. This group includes the cushion star, and the leather star. Families According to the World Register of Marine Species, the following families are included in Valvatida: * family Acanthasteridae Gervais, 1841 * family Archasteridae Viguier, 187 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinoderm
An echinoderm () is any animal of the phylum Echinodermata (), which includes starfish, brittle stars, sea urchins, sand dollars and sea cucumbers, as well as the sessile sea lilies or "stone lilies". While bilaterally symmetrical as larvae, as adults echinoderms are recognisable by their usually five-pointed radial symmetry (pentamerous symmetry), and are found on the sea bed at every ocean depth from the intertidal zone to the abyssal zone. The phylum contains about 7,600 living species, making it the second-largest group of deuterostomes after the chordates, as well as the largest marine-only phylum. The first definitive echinoderms appeared near the start of the Cambrian. Echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs and limbs; in some cases, they can undergo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinaster Serpentarius
''Echinaster'' is a well-studied and common genus of starfish containing ~30 species and is the second-largest genus found within the family Echinasteridae. The genera ''Henricia'' and ''Echinaster'' encompass 90% of all the species found within the family Echinasteridae. It contains 30 species, however the number of species in this genus is still debatable because of uncertainty within the genera. This genus is currently sub-divided into two sub-genera: ''Echinaster'' and ''Othilia'', evolutionary relationships between the sub-genera is not understood. ''Echinaster'' are found in the Pacific, Atlantic and Indian oceans, with most species being studied in the Gulf of Mexico and Brazil. The sub-genera ''Othilia'' is thought to encompass species mainly found in the Gulf of Mexico and Brazil. ''Echinaster'' is often one of the most studied species within the family Echinasteridae and is often used to find evolutionary relationships. Many species found within ''Echinaster'' are red, o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forcipulatida
The Forcipulatida are an order (biology), order of sea stars, containing three families and 49 genera. Description Forcipulatids share with the Brisingida, brisingid sea stars distinctive pedicellariae, consisting of a short stalk with three skeletal Ossicle (echinoderm), ossicles. Unlike that group, however, the forcipulatids tend to have more robust bodies. The order includes some well-known species, such as the common starfish, ''Asterias rubens''. This order can be commonly found from North Carolina in the United States all the way to Santos in Brazil. Phylogeny The order is divided into three families: * Family Asteriidae — 39 genera * Family Heliasteridae — two genera * Family Zoroasteridae — eight genera World Register of Marine Species gives another taxonomy, with 7 families and 64 genera: * Family Asteriidae Gray, 1840 * Family Heliasteridae Viguier, 1878 * Family Pedicellasteridae Perrier, 1884 * Family Pycnopodiidae Fisher, 1928 * Family Stichasteridae Perrie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brittle Star
Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to in length on the largest specimens. The Ophiuroidea contain two large clades, Ophiurida (brittle stars) and Euryalida (basket stars). Over 2,000 species of brittle stars live today. More than 1,200 of these species are found in deep waters, greater than 200 m deep. Range The ophiuroids diverged in the Early Ordovician. Ophiuroids can be found today in all of the major marine provinces, from the poles to the tropics. Basket stars are usually confined to the deeper parts of this range; Ophiuroids are known even from abyssal (>6,000 m) depths. However, brittle stars are also common members of reef communities, where they hide under rocks and even w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forcipulatacea
The Forcipulatacea are a superorder of sea stars. Subdivision * Order Forcipulatida * Order Brisingida * ''Incertae sedis or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty ...'': ** Family Paulasteriidae References Asteroidea {{Asteroidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Notomyotida
Benthopectinidae is a family of sea stars containing at least 75 species in eight genera. It is the only family in the monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unisp ... order Notomyotida. These asteroids are deep-sea dwelling and have flexible arms. The inner dorso-lateral surface of the arms contain characteristic longitudinal muscle bands. Eight genera of deep-water species make up the majority of the family benthopectinidae, and many of its members are expected to have a greater range than is currently recognized. Shin. (2015). A New Record of Sea Star Genus Nearchaster (Asteroidea: Notomyotida: Benthopectinidae) from East Sea, Korea. Animal Systematics, Evolution and Diversity, 31(2), 135–138. https://doi.org/10.5635/ASED.2015.31.2.135 Taxonomy Nine genera are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protoreaster Nodosus
''Protoreaster nodosus'', commonly known as the horned sea star or chocolate chip sea star, is a species of sea star found in the warm, shallow waters of the Indo-Pacific region. They are sometimes seen in the marine aquarium trade or dried and sold as curios. Description ''P. nodosus'' possess rows of spines or "horns"; black conical points arranged in a single row, radially on the dorsal side, which may erode and become blunt. These dark protrusions can intimidate possible predators by looking frightening or dangerous. On the ventral side, tube feet, purple in color (or pale, transparent pink), are arranged in rows on each arm. Most horned sea stars found are a roughly rigid five-pointed star-shape with tapering arms to the end, although there are anomalies like four or six-armed specimens; they may grow up to in diameter. The sea stars are usually colored in shades of red or brown, but can be light tan, resembling the color of cookie dough. This coloration, combined with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Velatida
The Velatida are an order of sea stars containing about 200 species in five families. These sea stars normally have thick bodies with large discs. Description and characteristics This order contains mostly deep or cold seas sea stars, often with a wide distribution (sometimes global). They have a pentagonal or star shape, with between 5 and 15 arms. Their skeleton is weakly developed, which confers them a good flexibility, and numerous papillae on the aboral surface allow them to breathe in poorly oxygenated waters. Their pedicellariae are often provided with spines. The smallest are Caymanostellidae (between 0,5 and 3 cm) and the biggest Pterasteridae (up to 30 cm). Taxonomy New molecular evidence now suggests a relationship between some velatid and valvatid families. List of families according to World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive catal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Concentricycloidea
Sea daisies (infraclass Concentricycloidea; order Peripodida) make up an unusual group of deep-sea taxa belonging to the phylum Echinodermata, with three species described in the genus ''Xyloplax''. Intestine and anus are absent. Distribution Sea daisies have been discovered in three localities, including deep-sea habitats off New Zealand, the Bahamas and most recently from the northern central Pacific. They have been collected primarily from sunken, deep-sea (1000+ meters) wood. Although known from only a handful of specimens initially, many specimens have now been collected from the Bahamas. Classification Since they were discovered in 1986, their position within the echinoderms has been debated. At first they were placed in a new class, Concentricycloidea, since it was unclear whether they might have affinities with asteroids or ophiuroids. The former view gained acceptance, and since 2006, they are currently considered a sister group to the Infraclass Neoasteroidea, which re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
