| Asterias | |
|---|---|
 | |
| Asterias rubens | |
Scientific classification | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Asteroidea |
| Order: | Forcipulatida |
| Family: | Asteriidae |
| Genus: | Asterias Linnaeus,1758 |
| Type species | |
| Asterias rubens Linnaeus, 1758 | |
| Species | |
See text | |
| Synonyms[1] | |
Asterias is agenus of theAsteriidae family ofsea stars. It includes several of the best-known species of sea stars, including the (Atlantic)common starfish,Asterias rubens, and thenorthern Pacific seastar,Asterias amurensis. The genus contains a total of eight species in all. All species have five arms and are native to shallow oceanic areas (thelittoral zone) of cold to temperate parts of theHolarctic. These starfish haveplanktonic larvae.Asterias amurensis is aninvasive species inAustralia and can in some years become apest in the Japanesemariculture industry.
The genusAsterias was first described byCarl Linnaeus in the10th edition of Systema Naturae in 1758 when he publishedA. 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 1825Thomas 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 asAsterias today.[2]
Johannes Peter Müller andFranz Hermann Troschel worked on starfish systematics in 1840, renaming the genusAsteracanthion and splitting a number of new genera from it.
William Stimpson rejected Müller and Troschel'sAsteracanthion in a paper presented on 4 December 1861, and named 16 new species, none of which are retained or included inAsterias at present.[3] In 1875Edmond Perrier formally reducedAsteracanthion to a synonym.[1]Francis Jeffrey Bell listed 78 species in the genus in 1881, arranging them in some 16 unranked groupings (seeartificial 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 sixsubgenera, of which subgenusAsterias, 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 1900sAddison Emery Verrill, working on the east coast of the US, added a number of new species to the genus, none of which are still inAsterias, and split the genus into numerous new genera and created new genera, moving almost all of the species now recognised as belonging toAsterias to his new genus ofAllasterias. He accepted six species for the Pacific coasts of North America, none of which remain inAsterias 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 ofAsterias, and synonymised Verrill's new genera ofAllasterias andParasterias withAsterias,[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 somezoologists from the United States to accept his new species.
Asterias, like most starfish genera in the orderForcipulatida, are recognisable externally by theirpedicellariae, 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 aspedicels.Papulae are also present. All species normally have five arms. Internally, theexoskeleton also presents some diagnostic characters, such as the dorsal plates bearing only a single spine in their centre.[8]
Sladen distinguishes it from the genusUniophora by the presence of spines on itsabactinal plates, instead of large, spherical tubercles; and fromAnasterias by the well-developed, reticulate, abactinal skeleton.[5]
TheWorld Register of Marine Species includes the following species:[1] Distributions from Djakonov (1950).[11]
| Image | Scientific name | Distribution |
|---|---|---|
 | Asterias amurensisLütken, 1871 | northern Pacific seastar: northernPacific in northernChina,South Korea,North Korea,Japan,Far East Russia,Alaska andCanada (British Columbia) |
| Asterias argonautaDjakonov, 1950 | Primorsky Krai (Peter the Great Gulf), South Korea | |
 | Asterias forbesi(Desor, 1848) | northwestAtlantic, fromLabrador south to theCaribbean Sea andGulf of Mexico |
| Asterias microdiscusDjakonov, 1950 | Avacha Bay on the southeastern coast of theKamchatka Peninsula,Karaginsky Island | |
| Asterias rathbuni(Verrill, 1909) | westernAlaska to Far East Russia (Kamchatka peninsula,Sea of Okhotsk andBering Sea) | |
| Asterias rollestoniBell, 1881 | around Japan, in theSea of Japan, and in theYellow Sea along the coasts of China. | |
 | Asterias rubensLinnaeus,1758 | common starfish: northern Atlantic inEurope from theWhite Sea of Russia to the Americas. |
| Asterias versicolorSladen, 1889 | around southern Japan,Taiwan,Hong Kong and theSouth China Sea. |
Data related toAsterias at WikispeciesAuthority control databases: National |
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