The genus Asterias was first described by Carl Linnaeus in the 10th edition of Systema Naturae in 1758 when he published A. rubens. It was for a time the only species, but by the early 1800s a few dozen taxa had been described in this genus.
In 1825 Thomas Say listed six species native to the coasts of the United States (which at the time consisted of the east coast from Maine to Florida, which the US had just formally acquired from Spain a few years earlier). None of these species are accepted or recognised as Asterias today.[2]
William Stimpson rejected Müller and Troschel's Asteracanthion in a paper presented on 4 December 1861, and named 16 new species, none of which are retained or included in Asterias at present.[3] In 1875 Edmond Perrier formally reduced Asteracanthion to a synonym.[1]Francis Jeffrey Bell listed 78 species in the genus in 1881, arranging them in some 16 unranked groupings (see artificial taxonomy).[4]
A few years later, in 1889, Percy Sladen counted 48 or 49 species in the genus. He split the genus into at least six subgenera, of which subgenus Asterias, section β of the Pentactinid (5-armed) section contained at least four species, three of which are still accepted in the genus today.[5]
In the early 1900s Addison Emery Verrill, working on the east coast of the US, added a number of new species to the genus, none of which are still in Asterias, and split the genus into numerous new genera and created new genera, moving almost all of the species now recognised as belonging to Asterias to his new genus of Allasterias. He accepted six species for the Pacific coasts of North America, none of which remain in Asterias at present.[6][7] Soon after, and in the following two decades, Walter Kenrick Fisher, working in California, synonymised or removed all of Verrill's species of Asterias, and synonymised Verrill's new genera of Allasterias and Parasterias with Asterias,[8] leaving the genus with four species, all of which are still recognised today.[9] Ryori Hayashi synonymised one further Japanese species in 1940, leaving the genus with three species known since the previous century, all of which are still recognised today.[10]
Alexander Michailovitsch Djakonov added two new species from Far East Russia in 1950 and reinstated the three species which were synonymised by Fisher and Hayashi, bringing the genus to eight species,[11] although it took until the 2000s for some zoologists from the United States to accept his new species.
Description
Aboral surface of an Asterias forbesi sea star showing ring of pedicellariae surrounding spine
Asterias, like most starfish genera in the order Forcipulatida, are recognisable externally by their pedicellariae, many thousands of tiny jaw-like structures on the skin which can snap shut to nip at prey or predators. Asterias has two types present -the major, also called straight, pedicellaria, which lie scattered across their skin, and the smaller minor, also called crossed, pedicellaria, which are found in tufts or wreaths around the large dorsal spines -these pedicellariae have tiny, rubbery stalks known as pedicels. Papulae are also present. All species normally have five arms. Internally, the exoskeleton also presents some diagnostic characters, such as the dorsal plates bearing only a single spine in their centre.[8]
Sladen distinguishes it from the genus Uniophora by the presence of spines on its abactinal plates, instead of large, spherical tubercles; and from Anasterias by the well-developed, reticulate, abactinal skeleton.[5]
The Valvatida are an order of starfish in the class Asteroidea, which contains 695 species in 172 genera in 17 families.
Asterias amurensis, also known as the Northern Pacific seastar and Japanese common starfish, is a seastar found in shallow seas and estuaries, native to the coasts of northern China, Korea, far eastern Russia, Japan, Alaska, the Aleutian Islands and British Columbia in Canada. Two forms are recognised: the nominate and formarobusta from the Strait of Tartary. It mostly preys on large bivalve molluscs, and it is mostly preyed on by other species of starfish. Population booms in Japan can affect the harvest of mariculture operations and are costly to combat.
The Echinasteridae are a family of starfish in the monotypic order Spinulosida. The family includes eight genera and about 133 species found on the seabed in various habitats around the world.
The Asteriidae are a diverse family of Asteroidea in the order Forcipulatida. It is one of three families in the order Forcipulatida.
Solaster paxillatus, the orange sun star, is a species of starfish found at varying depths in the northern Pacific Ocean. It is a natural predator of the starfish Asterias amurensis.
The Forcipulatida are an order of sea stars, containing three families and 49 genera.
The Brisingids are deep-sea-dwelling starfish in the order Brisingida.
Henricia is a large genus of slender-armed sea stars belonging to the family Echinasteridae. It contains about fifty species.
Leptasterias is a genus of starfish in the family Asteriidae. Members of this genus are characterised by having six arms although five-armed specimens sometimes occur. L. muelleri is the type species. The taxonomy of the genus is confusing and Leptasterias hexactis seems to be a species complex. Some species brood their eggs.
Solaster is a genus of sea stars in the family Solasteridae.
Evasterias troschelii is a species of starfish in the family Asteriidae. Its common names include the mottled star, false ochre sea star and Troschel's true star. It is found in Kamchatka and the north western coast of North America.
Stylasterias is a genus of starfish in the family Asteriidae. Stylasterias forreri, the velcro star, is the only species in the genus. It is found on the Pacific coast of Canada and the United States.
Leptasterias tenera is a species of starfish in the family Asteriidae. It is found on the eastern coast of North America.
The Brisingidae are a family of starfish found only in the deep sea. They inhabit both the Atlantic and Pacific Oceans at abyssal depths, and also occur in the Southern Ocean and around Antarctica at slightly shallower depths.
Marthasterias is a genus of starfish in the family Asteriidae. It is monotypic and the only species in the genus is Marthasterias glacialis, commonly known as the spiny starfish. It is native to the eastern Atlantic Ocean.
Euretaster insignis, commonly known as the striking sea star, is a species of starfish in the family Pterasteridae found in the central west Pacific Ocean. It is one of only three species in the order Velatida to be found in shallow water in the tropics. The young are brooded in a cavity underneath a "supradorsal" membrane.
Asterias rollestoni is a common starfish native to the seas of China and Japan, and not known from the far north or the American coasts of the eastern Pacific.
Asterias rathbuni is a starfish native to the Pacific coasts of Alaska in the United States and Far East Russia. There are two subspecies.
Asterias versicolor is a species of starfish native to the southern coasts of Japan southwards to the South China Sea.
Rathbunaster is a monospecific genus of sea stars belonging to the family Asteriidae. The genus name was given by Walter Kenrick Fisher as a honorific of the starfish biologist Richard Rathbun of the Smithsonian Institution. He originally ranged this genus under the family Pycnopididae, synonymous with Asteriidae.
References
1 2 3 Mah, Christopher L. (2007). "Asterias Linnaeus, 1758". World Register of Marine Species (WoRMS). Flanders Marine Institute. Retrieved 16 November 2019.
1 2 Дьяконов, А.М. (1950). Морские звезды морей СССР [Определители по фауне. 34 (Tableaux analytiques de la faune de l'URSS 34)] (in Russian). St. Petersburg: Акаде́мии Нау́к СССР. pp.121–128.
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