View source for Asterias

{{Short description|Genus of starfishes}}
{{Automatic taxobox
| image = Asterias_rubens.jpg
| image_caption = ''[[Asterias rubens]]''
| taxon = Asterias
| authority = [[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]
| subdivision_ranks = Species
| subdivision = See text
| synonyms =
*''Allasterias'' <small>[[Addison Emery Verrill|Verrill]], 1909</small>
*''Asteracanthion'' <small>[[Johannes Peter Müller|Müller]] & [[Franz Hermann Troschel|Troschel]], 1840</small>
*''Asteracanthium'' <small>[[Johann Friedrich Brandt|Brandt]], 1851</small>
*''Parasterias'' <small>Verrill, 1914</small>
*''Stellonia'' <small>[[Giovanni Domenico Nardo|Nardo]], 1834</small>
*''Uraster'' <small>[[Louis Agassiz|L. Agassiz]], 1836</small>
| synonyms_ref = <ref name=WoRMS>{{cite web |url=http://www.marinespecies.org/aphia.php?p=taxdetails&id=123219 |title=''Asterias'' Linnaeus, 1758 |last=Mah |first=Christopher L. |date=2007 |website=World Register of Marine Species (WoRMS) |publisher=Flanders Marine Institute |access-date=16 November 2019}}</ref>
| type_species = ''[[Asterias rubens]]''
| type_species_authority = [[Carl Linnaeus|Linnaeus]], 1758
}}
'''''Asterias''''' is a [[genus]] of the [[Asteriidae]] family of [[sea star]]s. It includes several of the best-known species of sea stars, including the ([[Atlantic]]) [[common starfish]], ''Asterias rubens'', and the [[northern 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 (the [[littoral zone]]) of cold to temperate parts of the [[Holarctic]]. These starfish have [[plankton]]ic larvae. ''Asterias amurensis'' is an [[invasive species]] in [[Australia]] and can in some years become a [[pest (organism)|pest]] in the Japanese [[mariculture]] industry.
==History==
The genus ''Asterias'' was first described by [[Carl Linnaeus]] in the [[10th edition of Systema Naturae]] in 1758 when he published [[Asterias rubens|''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.<ref>{{cite journal |last=Say |first=Thomas |author-link=Thomas Say |date=1825 |title=On the species of the Linnaean genus ''Asterias'' inhabiting the coast of the United States |url=https://biodiversitylibrary.org/page/9492679 |journal=Journal of the Academy of Natural Sciences of Philadelphia |volume=5 |issue=1 |pages=506–507 |access-date=16 November 2019}}</ref>
[[Johannes Peter Müller]] and [[Franz Hermann Troschel]] worked on starfish systematics in 1840, renaming the genus ''Asteracanthion'' and splitting a number of new genera from it.
[[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.<ref name=Stimpson1861>{{cite journal |last=Stimpson |first=William |author-link=William Stimpson |date=1862 |title=On New Genera and Species of Starfishes of the Family Pycnopodidæ (''Asteracanthion'' Müll. and Trosch.) |url=https://biodiversitylibrary.org/page/9492675 |journal=Proceedings of the Boston Society of Natural History |volume=8 |pages=261–273 |access-date=16 November 2019}}</ref> In 1875 [[Edmond Perrier]] formally reduced ''Asteracanthion'' to a synonym.<ref name=WoRMS/> [[Francis Jeffrey Bell]] listed 78 species in the genus in 1881, arranging them in some 16 unranked groupings (see [[Taxonomy (biology)#History|artificial taxonomy]]).<ref name=Bell1881>{{cite journal |last=Bell |first=Francis Jeffrey |author-link=Francis Jeffrey Bell |date=1881 |title=1. Contributions to the Systematic Arrangement of the Asteroidea. I The species of the genus ''Asterias'' |url=https://www.biodiversitylibrary.org/page/30759679#page/636 |journal=Proceedings of the Zoological Journal of London |pages=503–507 |access-date=16 November 2019}}</ref>
A few years later, in 1889, [[Percy Sladen]] counted 48 or 49 species in the genus. He split the genus into at least six [[subgenus|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.<ref name=Sladen1889>{{cite book |last=Sladen |first=Walter Percy |date=1889 |title=Report on the Scientific Results of the Voyage of H.M.S. Challenger during the years 1873–1876, Zoology 30, Report on the Asteroidea (part 51) |url=http://www.19thcenturyscience.org/HMSC/HMSC-Reports/Zool-51/htm/doc564.html |location=London |publisher=Government of the United Kingdom |pages=560–564 |author-link=Percy Sladen}}</ref>
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.<ref name=Verrill1909>{{cite journal |last=Verrill |first=Addison Emery |author-link=Addison Emery Verrill |date=1909 |title=Description of new genera and species of starfishes from the North Pacific coast of America |url=https://biodiversitylibrary.org/page/40247729 |journal=American Journal of Science |volume=28 |pages=65–70 |access-date=16 November 2019}}</ref><ref name=Verrill1914>{{cite journal |last=Verrill |first=Addison Emery |author-link=Addison Emery Verrill |date=1914 |title=Monograph of the shallow-water starfishes of the North Pacific coast from the Arctic Ocean to California |url=https://biodiversitylibrary.org/page/20755294 |journal=Harriman Alaska Series |volume=14 |pages=101–116, 188–196 |doi=10.5962/bhl.title.25926 |access-date=16 November 2019|doi-access=free }}</ref> 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'',<ref name=Fisher1923>{{cite journal |last=Fisher |first=Walter Kenrick |author-link=Walter Kenrick Fisher |date=1923 |title=A preliminary synopsis of the Asteriidae, a family of sea-stars |url=https://archive.org/details/cbarchive_51377_apreliminarysynopsisoftheaster1840 |journal=Annals and Magazine of Natural History |volume=12 |issue=9 |pages=[https://archive.org/details/cbarchive_51377_apreliminarysynopsisoftheaster1840/page/n5 248]-249, 598-599 |access-date=16 November 2019}}</ref> leaving the genus with four species, all of which are still recognised today.<ref name=Fisher1930>{{cite journal |last=Fisher |first=Walter Kenrick |author-link=Walter Kenrick Fisher |date=1930 |title=Asteroidea of the North Pacific and Adjacent Waters, Part 3: Forcipulata |url=https://archive.org/details/bulletinunitedst7631930unit |journal=United States National Museum Bulletin |volume=76 |issue=3 |publisher=U.S. Government Printing Office |pages=[https://archive.org/details/bulletinunitedst7631930unit/page/5 5]–6 |access-date=16 November 2019}}</ref> 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.<ref name=Hayashi1940>{{cite journal |last=Hayashi |first=Ryori |date=1940 |title=Contributions to the Classification of the Sea-stars of Japan |url=https://eprints.lib.hokudai.ac.jp/dspace/bitstream/2115/27045/1/8%283%29_P133-281.pdf |journal=北海道帝國大學理學部紀要 (Journal of the Faculty of Science Hokkaido Imperial University) Series VI. Zoology |volume=7 |issue=3 |pages=223–226 |access-date=17 November 2019}}</ref>
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,<ref name=Дьяконов1950>{{cite book |last=Дьяконов |first=А.М. |date=1950 |title=Морские звезды морей СССР [Определители по фауне. 34 (Tableaux analytiques de la faune de l'URSS 34)] |language=ru |location=[[St. Petersburg]] |publisher=[[Russian Academy of Sciences#The Academy of Sciences of the USSR|Акаде́мии Нау́к СССР]] |pages=121–128}}</ref> although it took until the 2000s for some [[zoologist]]s from the United States to accept his new species.
==Description==
[[File:Asterias forbesi ring of pedicellaria around spine.jpg|thumb|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 [[Pedicel (botany)|pedicel]]s. [[Papula]]e 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.<ref name=Fisher1923/>
Sladen distinguishes it from the genus ''[[Uniophora]]'' by the presence of spines on its [[wikt:abactinal|abactinal]] plates, instead of large, spherical tubercles; and from ''[[Anasterias]]'' by the well-developed, reticulate, abactinal skeleton.<ref name=Sladen1889/>
==Species==
The [[World Register of Marine Species]] includes the following species:<ref name=WoRMS/> Distributions from Djakonov (1950).<ref name=Дьяконов1950/>
{| class="wikitable"
|-
! Image !! Scientific name !!  Distribution
|-
|[[File:海星（正面）.JPG|120px]]||''[[Asterias amurensis]]'' <small>[[Christian Frederik Lütken|Lütken]], 1871</small> ||'''northern Pacific seastar''': northern [[Pacific]] in northern [[China]], [[South Korea]], [[North Korea]], [[Japan]], [[Far East Russia]], [[Alaska]] and [[Canada]] ([[British Columbia]])
|-
| || ''[[Asterias argonauta]]'' <small>[[Alexander Michailovitsch Djakonov|Djakonov]], 1950</small> || [[Primorsky Krai]] ([[Peter the Great Gulf]]), South Korea
|-
|[[File:Asterias forbesi 163772473.jpg|120px]]||''[[Asterias forbesi]]'' <small>([[Pierre Jean Édouard Desor|Desor]], 1848)</small>|| northwest [[Atlantic]], from [[Labrador]] south to the [[Caribbean Sea]] and [[Gulf of Mexico]]
|-
| || ''[[Asterias microdiscus]]'' <small>Djakonov, 1950</small> || [[Avacha Bay]] on the southeastern coast of the [[Kamchatka Peninsula]], [[Karaginsky Island]]
|-
| || ''[[Asterias rathbuni]]'' <small>([[Addison Emery Verrill|Verrill]], 1909)</small> ||western [[Alaska]] to Far East Russia (Kamchatka peninsula, [[Sea of Okhotsk]] and [[Bering Sea]])
|-
| ||''[[Asterias rollestoni]]'' <small>[[Francis Jeffrey Bell|Bell]], 1881</small> || around Japan, in the [[Sea of Japan]], and in the [[Yellow Sea]] along the coasts of China.
|-
|[[File:Sea-Star-Ship-Harbor-Acadia-NP.jpg|120px]]||''[[Asterias rubens]]'' <small>[[Carl Linnaeus|Linnaeus]], [[10th edition of Systema Naturae|1758]]</small> || '''common starfish''': northern Atlantic in [[Europe]] from the  [[White Sea]] of Russia to the Americas.
|-
| ||''[[Asterias versicolor]]'' <small>[[Percy Sladen|Sladen]], 1889</small> || around southern Japan, [[Taiwan]], [[Hong Kong]] and the [[South China Sea]].
|-
|}
==References==
{{Reflist}}
==External links==
* [http://www.glaucus.org.uk/Asterias.htm British Marine Life Study Society page on ''Asterias rubens'']
* {{Wikispecies-inline|Asterias}}
{{Taxonbar|from=Q1952205}}
{{Authority control}}
[[Category:Asterias| ]]
[[Category:Asteroidea genera]]
[[Category:Taxa named by Carl Linnaeus]]