This is the most common, large intertidal sea star and it occurs in great numbers on mussel beds on exposed coasts. Pisaster ochraceous is more tolerant to air exposure than any other Pisaster.
Sea otters and gulls prey on this starfish. Pisaster ochraceus can retract such sensitive areas as the podia and skin papillae. Additionally, they may be able to shut the ambulacral grooves which contain the tube-feet, and then spread the spines over them protectively.
Known Predators:
The radius of P. ochraceus is anywhere from about 10 to 18 inches (25 to 45 cm) in diameter. Yellow, orange, brown, reddish or even purple make up the ranging colors of this heavy starfish. Basically it has a good size middle disk with five stout arms sticking out. On its upper side it has short, white spines in the pentagonal pattern.
Other Physical Features: ectothermic ; heterothermic ; radial symmetry
From studies in oceans and aquariums, it seems that many asteroids achieve a minimal life span of four to six years, and Pisaster ochraceous could reach an age of twenty years.
Typical lifespan
Status: wild: 20 (high) years.
Pisaster ochraceous can be found on wave-washed rocky shores, from above the low-tide zone to 90 m in depth. Because they can live in shallow water they need to survive in these living conditions, including strong surges, big temperature changes, dilution by rainfall, and dessication. Pisaster ochraceous is very resistant to dessication and it can tolerate a loss of thirty-percent of its body weight in body fluids.
Range depth: 90 (high) m.
Habitat Regions: temperate ; saltwater or marine
Aquatic Biomes: coastal
Other Habitat Features: intertidal or littoral
The neurosensory cells scattered over the asteroid body respond to mechanical, chemical, and optical stimuli. Sensory organs are developed only at the base of each terminal tentacle. At this location a great number of light-sensitive cells form an optic cushion which contains several ocelli.
Communication Channels: chemical
Perception Channels: visual ; tactile ; chemical
US Migratory Bird Act: no special status
US Federal List: no special status
CITES: no special status
Pisaster ochraceous develops through several larval stages, one including the brachiolaria larva. Using ciliated arms to sweep food into its mouth, it glides through the water column. The cilia drive locomotion of the larva is supplemented by these same arms. The larva attaches itself to the substratum as it settles because each arm has a glandular tip. The five-armed adult is formed because it undergoes metamorphosis. Adults continue growing and the rate of growth is dependent on its food supply.
Development - Life Cycle: metamorphosis
Pisaster ochraceous can be found anywhere from Alaska to Baja California. It is most commonly found in the Northeastern Pacific, being that it is a cold-water species. However, it is common in bays all year.
Biogeographic Regions: pacific ocean
At the larval stage, Pisaster ochraceus are filter feeders, eating plankton.
Like all sea stars, an adult P. ochraceus has tube feet which they use for locomotion and for handling prey. Pisaster ochraceous feeds on mussels, chitons, and limpets, which they slowly pry open and devour. Snails, barnacles, echinoids, even decapod crustacea are also eaten. Pisaster ochraceous everts its stomach over the prey if it is too large to be swallowed whole, and digests the prey before swallowing it.
Animal Foods: mollusks; aquatic crustaceans; echinoderms; other marine invertebrates; zooplankton
Plant Foods: phytoplankton
Foraging Behavior: filter-feeding
Primary Diet: carnivore (Eats non-insect arthropods, Molluscivore , Eats other marine invertebrates); planktivore
Pisaster ochraceous is a predator and is a prey to sea otters and sea gulls. Its role as a keystone species has been well studied. In intertidal areas of Washington, when it was removed, the diversity of species in the area decreased.
Ecosystem Impact: keystone species
The only positive benefit for humans is that they are admired by tourists as they are clinging to the rocks on a bay area.
Positive Impacts: research and education
Pisaster ochraceous is mainly dioecious. The male gametes develop, but later only females ones are produced. During a transitional period, both eggs and sperm are produced. A pair of gonads branches into each arm off a circular genital strand located along the oral inner surface of the disc. Each gonad looks like a feathery cluster of tubules. During maturation of the gametes, the gonads greatly increase in size, pushing into the perivisceral cavity of the arms, often right up to the ends of the arms. The gonopores of the individual gonads open at the bases of the arms.
Breeding season: Spring
Key Reproductive Features: gonochoric/gonochoristic/dioecious (sexes separate); sexual ; fertilization (External ); broadcast (group) spawning
There is no parental investment beyond spawning.
Parental Investment: pre-fertilization (Provisioning)
This species has a broad distribution in the Pacific from Alaska to Panama.
In Panama this species has been collected from Taboga Island (USNM E45306), Panama Bay, Gulf of Panama, eastern Pacific, North Pacific Ocean.
Fisher, W.K. (1930). Asteroidea of the North Pacific and Adjacent Waters, Pt. 3: Forcipulata (Concluded). Bulletin of the United States National Museum 76: 1-356.Pls. 1-93.
LSID urn:lsid:marinespecies.org:taxname:240755Asteracanthion margaritifer Müller & Troschel, 1842 (Synonym according to Fisher (1930))
Asterias conferta Stimpson, 1862
Asterias fissispina Stimpson, 1862 (Synonym according to Fisher (1926, 1930))
Asterias janthina Brandt, 1835 (Synonym according to Fisher (1930))
Asterias margaritifera Brandt in Fisher, 1930 (Synonym according to Fisher (1930))
Asterias ochracea Brandt, 1835
Pisaster fissispinus (Stimpson, 1862) (Synonym according to Fisher (1926, 1930))
Pisaster ochraceus broadcast spawns in the spring, from late May to mid June. Each starfish releases millions of small eggs and sperm. The larvae are planktotrophic and spend about 2 months in the water column before settling. Planktotrophic larvae are dependent on planktonic food. The timing of gamete release coincides with the spring plankton bloom to increase survival likelihood. Broadcast spawners see high pre-adult and low adult mortality. Since larvae survival depends on the quality and quantity of food, broadcast spawning is beneficial for greater dispersal to increase the chances of finding abundant and high quality food. Pisaster ochraceus reaches maturity at a wet-weight of 70-90 grams, which usually takes about 5 years. The long length of maturation is hypothesized to be so that the seastar is robust enough to produce two offpsring that survive to sexual maturity. This allows Pisaster ochraceus a greater chance of successfully replacing itself.
Pisaster ochraceus is the first sea star species observed with “starfish wasting syndrome,” a plague of significant concern to scientists, which causes sea stars along the North American Pacific coast to soften, lose their arms, and eventually disintegrate, sometimes just days after first symptoms appear.The outbreak is similar die-offs in 1970 and in 1990, however far more geographically expansive and affecting far more individuals. Scientists first sighted symptoms of the syndrome in September 2013 on sea stars on the Olympic Penninsula in Washington state; since then, massive population declines of many sea star species have been documented along much of the North American west coast, and continue to erupt in previously unaffected areas.
Known as a “keystone species” in the marine intertidal and subtidal ecosystems, the sharp population decline of P. ochraceus is expected to trigger wide-ranging changes in the relative compositions of other species, and cause a fundamental disruption at ecosystem level.Scientists still do not know the underlying cause for the wasting syndrome, and are examining potential infectious agents and environmental changes that might be implicated.
(Raimondi 2014; SeaStarWasting.org 2014 and references therein)
Pisaster ochraceus ist eine Art der Seesterne aus der Ordnung der Zangensterne (Forcipulata), die an der nordamerikanischen Pazifikküste häufig ist. Als Hauptfeind der kalifornischen Miesmuscheln gilt sie als Schlüsselart im dortigen Ökosystem.
Pisaster ochraceus hat fünf kräftige Arme, die 10 cm bis 25 cm lang werden und nicht deutlich von der Mundscheibe abgesetzt sind. Die dickste Stelle der Arme ist im Gegensatz zu manchen anderen Arten an der Basis. Die Seesterne sind meist purpurfarben, können aber auch orange, orange-ocker, gelb, rötlich oder braun sein. Die Kalkstacheln in der Haut der Oberseite werden nicht länger als 2 mm und sind auf der Mittelscheibe in einem netzartigen oder pentagonalen Muster angeordnet. Die Saugfüßchen haben in Anpassung an die starke Brandung besonders kräftige Saugscheiben, mit denen sich der Seestern sehr gut am felsigen Untergrund festhalten kann.[1][2][3]
Pisaster ochraceus kann mit drei anderen Arten leicht verwechselt werden: Pisaster giganteus hat blaue Ringe und weiße bis rosafarbene Stacheln, Pisaster brevispinus dagegen ist rosafarben mit kleinen weißen Stacheln. Evasterias troscheli hat eine kleinere Mittelscheibe und längere, zugespitzte Arme, deren dickste Stelle etwas außen von der Basis und nicht wie bei Pisaster ochraceus direkt an derselben ist.[2]
Pisaster ochraceus ist wie andere Seesterne getrenntgeschlechtlich, und Männchen und Weibchen lassen sich nur anhand vorhandener Eizellen oder Spermien in den Keimdrüsen unterscheiden.[2]
In jedem Arm gibt es zwei Keimdrüsen aus federartigen Röhrchen nahe der Mundscheibe. Die Keimöffnungen sind mit bloßem Auge nicht zu erkennen und nur bei der Abgabe der Keimzellen auszumachen. Die Eierstücke sind orange und die Hoden weißlich. Bei der Reifung der Keimzellen schwellen die Keimdrüsen an und können 40 % des Körpergewichts einnehmen.[3]
Die Keimzellen werden in Puget Sound zwischen Mai und Juli abgegeben. Die Eizellen werden im freien Wasser befruchtet, und Pisaster ochraceous entwickelt sich wie andere Seesterne über mehrere frei schwimmende Larvenstadien.[2]
Während viele andere Seesterne etwa 4 Jahre alt werden, erreicht Pisaster ochraceus ein Alter von bis zu 20 Jahren.[4]
Pisaster ochraceus kommt an der nordamerikanischen Pazifikküste von Prince William Sound in Alaska bis Point Sal in Santa Barbara County in Kalifornien vor. Im wärmeren Meerwasser von Santa Barbara County bis Baja California lebt die Unterart Pisaster ochraceus segnis.[5] Der Seestern lebt in großer Anzahl auf Felsen und auf Muschelbänken in der Gezeitenzone bis in eine Tiefe von etwa 90 m. Jungtiere sind häufig in Spalten und unter Felsen zu finden. Pisaster ochraceous verträgt einen Gewichtsverlust von bis zu 30 % seines Körpergewichts.[4]
Als Larve ernährt sich Pisaster ochraceus filtrierend von Plankton, doch nach der Metamorphose zum Adulttier lebt er als Fleischfresser.
Pisaster ochraceus frisst eine Vielzahl von Tieren, in erster Linie Miesmuscheln wie Mytilus californianus und Mytilus trossulus. Weitere Beutetiere sind unter anderem Käferschnecken, Napfschnecken, verschiedene andere Schnecken, Seepocken, Entenmuscheln, Seeigel und Zehnfußkrebse.[6]
Pisaster ochraceus verwendet seine Saugfüßchen, um Muscheln zu öffnen. Muss die Muschel die Schalen zum Atmen öffnen, ist dies für den Seestern die Gelegenheit, die Schalen weiter auseinanderzuziehen. Er vermag Teile des ausgestülpten Magens in einen schmalen Spalt zwischen den Muschelschalen durchzuzwängen und Verdauungsenzyme abzugeben. Die Muschel wird in ihren Schalen vorverdaut (extraintestinale Verdauung) und vom Seestern durch Einstülpen des Magens aufgenommen. Ein Pisaster ochraceus kann nach Schätzungen etwa 80 Kalifornische Miesmuscheln im Jahr fressen.[7]
Pisaster ochraceus hat nur wenige natürliche Feinde: Seeotter und Möwen. Als Hauptfeind gilt der Mensch, der Seesterne als Sammelstücke absammelt.[8]
Das Ökosystem an der kalifornischen Pazifikküste wird bereits seit Jahrzehnten untersucht. Pisaster ochraceus wird als Schlüsselart im Nahrungsgefüge der dortigen Gezeitenzonen eingestuft. Als Fressfeind der kalifornischen Miesmuschel Mytilus californianus vermindert er deren Häufigkeit, so dass auch andere Tiere dort leben können. In einem Feldexperiment von Robert T. Paine in den 1960er-Jahren wurde Pisaster ochraceus abgesammelt, so dass Mytilus californianus sich massenhaft vermehrte und andere Arten verdrängte.[9] Deshalb wird das Vorhandensein von Pisaster ochraceus als wesentlich für die Erhaltung der Artenvielfalt in der Lebensgemeinschaft der Gezeitenzone Kaliforniens angesehen.[10][11]
Pisaster ochraceus ist eine Art der Seesterne aus der Ordnung der Zangensterne (Forcipulata), die an der nordamerikanischen Pazifikküste häufig ist. Als Hauptfeind der kalifornischen Miesmuscheln gilt sie als Schlüsselart im dortigen Ökosystem.
ஊதாக் கடல் விண்மீன் (Purple Sea Star) அல்லது காவிவண்ண நட்சத்திரமீன் (Ochre Sea Star) பசிபிக் பெருங்கடற் பகுதியில் பொதுவாகக் காணப்படும் ஒரு கடல் விண்மீன் இனமாகும் (Pisaster ochraceus). மறைதிறவு இனக் கருதுகோளில் (en:keystone species) முக்கியமானதாக இவ்வினம் விளங்குகின்றது. கலிபோர்னிய கருநீலச்சிப்பி (Mytilus californianus ) போன்ற சிப்பி இனங்களிற்கு கொன்றுண்ணியாக விளங்கி அவற்றை உணவாகப் பயன்படுத்துவதன் மூலம் ஊதாக் கடல் விண்மீன்கள் சூழ்நிலையியல் சமநிலையைப் பேணுகின்றன. இத்தகைய விண்மீன்கள் இல்லாத சந்தர்ப்பம் ஒன்று செயற்கையாக உருவாக்கப்பட்டபோது கருநீலச்சிப்பிகளின் எண்ணிக்கை பெருகியது, அலையிடை கடல் மண்டலத்தில் அவற்றின் ஆதிக்கம் பெரிதாகியது, இது சிப்பிகளின் உண்ணும் தாவர வகையான மிதவைத் தாவர உயிரிகள் (en:Phytoplankton) அழிக்கப்படுவதற்கு உந்துகோலாக அமைந்தது.[1]
இந்த நிகழ்வு, சூழ்நிலையியலில் ஒரு தீங்கான விளைவாகும். புவியின் வளிமண்டலத்திற்கு ஒட்சிசனை வழங்குவதில் இந்த மிதவைத் தாவர உயிரிகள் முக்கிய பங்கை ஆற்றுகின்றன. மிதவைத் தாவர உயிரிகளின் எதிரியான சிப்பி இனங்களை மட்டுப்படுத்தி வைத்திருப்பதனால் நட்சத்திரமீன் ஒரு திறவு இனமாக, சூழலைப் பாதுகாக்கும் உயிரியாக நோக்கப்படுகின்றது.
கடல் விண்மீன் கூட்டம், பிரிட்டிஷ் கொலம்பியா
ஊதாக் கடல் விண்மீன் (Purple Sea Star) அல்லது காவிவண்ண நட்சத்திரமீன் (Ochre Sea Star) பசிபிக் பெருங்கடற் பகுதியில் பொதுவாகக் காணப்படும் ஒரு கடல் விண்மீன் இனமாகும் (Pisaster ochraceus). மறைதிறவு இனக் கருதுகோளில் (en:keystone species) முக்கியமானதாக இவ்வினம் விளங்குகின்றது. கலிபோர்னிய கருநீலச்சிப்பி (Mytilus californianus ) போன்ற சிப்பி இனங்களிற்கு கொன்றுண்ணியாக விளங்கி அவற்றை உணவாகப் பயன்படுத்துவதன் மூலம் ஊதாக் கடல் விண்மீன்கள் சூழ்நிலையியல் சமநிலையைப் பேணுகின்றன. இத்தகைய விண்மீன்கள் இல்லாத சந்தர்ப்பம் ஒன்று செயற்கையாக உருவாக்கப்பட்டபோது கருநீலச்சிப்பிகளின் எண்ணிக்கை பெருகியது, அலையிடை கடல் மண்டலத்தில் அவற்றின் ஆதிக்கம் பெரிதாகியது, இது சிப்பிகளின் உண்ணும் தாவர வகையான மிதவைத் தாவர உயிரிகள் (en:Phytoplankton) அழிக்கப்படுவதற்கு உந்துகோலாக அமைந்தது.
இந்த நிகழ்வு, சூழ்நிலையியலில் ஒரு தீங்கான விளைவாகும். புவியின் வளிமண்டலத்திற்கு ஒட்சிசனை வழங்குவதில் இந்த மிதவைத் தாவர உயிரிகள் முக்கிய பங்கை ஆற்றுகின்றன. மிதவைத் தாவர உயிரிகளின் எதிரியான சிப்பி இனங்களை மட்டுப்படுத்தி வைத்திருப்பதனால் நட்சத்திரமீன் ஒரு திறவு இனமாக, சூழலைப் பாதுகாக்கும் உயிரியாக நோக்கப்படுகின்றது.
கடல் விண்மீன் கூட்டம், பிரிட்டிஷ் கொலம்பியா
Pisaster ochraceus, generally known as the purple sea star, ochre sea star, or ochre starfish, is a common seastar found among the waters of the Pacific Ocean. Identified as a keystone species, P. ochraceus is considered an important indicator for the health of the intertidal zone.[2]
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This sea star has five stout rays that range in length from 10 to 25 centimeters (4 to 10 in). The rays are arranged around an ill-defined central disk. While most individuals are purple, they can be orange, orange-ochre, yellow, reddish, or brown. The aboral surface contains many small spines (ossicles) that are arranged in a netlike or pentagonal pattern on the central disk. The ossicles are no higher than 2 mm.[3][4] In Pisaster the tube feet have suckers on their distal ends which allow them to attach to the rocky substrate and live in heavily wave-swept areas.[5] P. ochraceus has a simple nervous system and does not have a brain. A nerve ring connects and relays impulses between the star's radial nerves.[6]
Two species that can be mistaken for P. ochraceus are P. giganteus, which has blue rings around white or purple spines, and P. brevispinus, which is pink with small white spines. These two species have different aboral spines and coloration which allows one to distinguish between the species. Evasterias troscheli may be confused with P. ochraceus at times as well. It can be distinguished by its smaller disk size and longer, tapering rays which are often thickest a short distance out from their base rather than at the base as in P. ochraceus.[4]
Members of Pisaster are dioecious but there is no sexual dimorphism and sexes can be separated only by the presence of eggs or sperm in the gonads. They reproduce by broadcast spawning, which occurs in the Puget Sound around May to July.[4] There is no parental investment beyond spawning.[7] Fertilization occurs in the water column and Pisaster ochraceous develops through several larval stages.[6]
The reproductive system consists of a pair of gonads branching into each ray off a circular genital strand which is along the oral inner surface of the central disc.[7] The gonads look like a feathery collection of tubules. In females there are orange gonads and in males they are whitish.[5] During maturation of the gametes, the gonads increase in size and can account for up to 40 percent of the sea star's weight.[4] The gonopores are too small to be seen, and can only be found when the sea stars are spawning.[4][6]
Many sea stars live to a minimal age of four years. P. ochraceus can live as long as twenty years.[7]
This species of seastar is often considered a keystone species in many intertidal regions. P. ochraceus is a predator of the California mussel, Mytilus californianus and reduces its abundance. This allows for other macroinvertebrates to persist. In an experimental removal of P. ochraceus, it was shown that Mytilus californianus becomes almost completely dominant of the intertidal community. When P. ochraceus is present there is a diverse intertidal community.[8]
At the larval stage, Pisaster ochraceus are filter feeders and their diet consists of plankton. As an adult, P. ochraceus feeds on mussels such as Mytilus californianus and Mytilus trossulus. They also feed on chitons, limpets, snails, barnacles, echinoids, and even decapod crustacea.[4][9][10]
P. ochraceus uses its tube feet to handle its prey. If the prey is too large to be swallowed whole, then it can use its tube feet to open shells. It can evert its stomach through its mouth and engulf its prey, liquify it with digestive enzymes and ingest the processed food. Mussels hold their valves together very securely but P. ochraceus can insert part of its everted stomach, or some digestive juices, through the narrow gap that exists where the byssal threads emerge from the shell. The mussel needs to open its valves periodically to feed and breathe and the sea star can exert a powerful traction with its tube feet, pulling the two valves further open. Once the stomach is inside the mussel, digestion takes place. It is thought one sea star can consume eighty Californian mussels in a year.[11]
_Starfish,_Oregon_coast.jpg)
Pisaster ochraceus has been described as a keystone species. Experiments by zoologist Robert T. Paine in the 1960s demonstrated that a loss of only a few individual P. ochraceus seastars had a profound impact on mussel bed population, thereby reducing the health of the intertidal environment.[2] With only a few natural predators (sea otters and seagulls) it is suggested that the principal enemies of P. ochraceus are human collectors and casual tidepool visitors.[12] Pisaster ochraceus has not been evaluated by the International Union for Conservation of Nature (IUCN).[7]
P. ochraceus can be found from Prince William Sound in Alaska to Point Sal in Santa Barbara Co., California. The subspecies found within the warmer waters from Santa Barbara County to Baja California is P. o. segnis.[13]
This sea star can be found in great numbers on mussel beds and on wave-washed rocky shores. The juveniles are often found in crevices and under rocks.[6] Its depth range is from above the low-tide zone to 90 m. P. ochraceous is very durable and can tolerate a loss of thirty percent of its body weight in body fluids.[7]
A study found that P. ochraceus will not be affected by ocean acidification in the same way as most calcareous marine animals. This normally causes decreased growth due to the increased acidity dissolving calcium carbonate. Researchers found that when P. ochraceus was exposed to 21 °C (70 °F) and 770 ppm CO2 (beyond rises expected in the next century) they survived. It is thought that this is because the animal's calcium is nodular and so it is able to compensate for the lack of carbonate by growing more fleshy tissue instead.[14][15]
Pisaster ochraceus, generally known as the purple sea star, ochre sea star, or ochre starfish, is a common seastar found among the waters of the Pacific Ocean. Identified as a keystone species, P. ochraceus is considered an important indicator for the health of the intertidal zone.
La estrella de mar ocre (Pisaster ochraceus) es una especie de equinodermo asteroideo de la familia Asteriidae.[1][2] Es una estrella de mar común de la costa del Pacífico de América del Norte.
La estrella de mar ocre (Pisaster ochraceus) es una especie de equinodermo asteroideo de la familia Asteriidae. Es una estrella de mar común de la costa del Pacífico de América del Norte.
Pisaster ochraceus est une espèce d'étoiles de mer, de la famille des Asteriidae. Elles sont communes sur la côte ouest des États-Unis.
Cette étoile possède 5 bras terminés en pointes émoussées et recouverts d’épines calcaires granuleuses disposées en motifs linéaires irréguliers, et formant sur le disque central un motif pentagonal entourant l'anus. Elle mesure en moyenne de 10 à 25 cm de diamètre, mais certains spécimens peuvent dépasser 30 cm (principalement à grandes profondeurs). Sa couleur est très variable, variant du jaune clair au violet, en passant par le jaune, l'orange, le rouge, le mauve et le violet.
Spécimens de différentes couleurs
Spécimen séché.
Cette étoile est très abondantes sur les côtes américaines, de l'Alaska à la Californie. Les spécimens les plus méridionaux appartiennent à la sous-espèce Pisaster ochraceus segnis.
On les trouve sur les substrats rocheux et accidentés (où elles peuvent facilement se cacher sous les roches pendant la journée), de la zone intertidale à plus de 90 m de profondeur.
Cette étoile se nourrit principalement de mollusques, qu'elle ouvre au moyen de ses puissants podia, mais elle ne dédaigne pas d'autres invertébrés lents ou sessiles, ou des charognes.
Dans la zone intertidale, elle est la proie d'oiseaux marins comme les goélands.
Selon World Register of Marine Species (31 mars 2014)[2] :
Pisaster ochraceus est une espèce d'étoiles de mer, de la famille des Asteriidae. Elles sont communes sur la côte ouest des États-Unis.
Pisaster ochraceus (species ab Ioanne Friderico de Brandt anno 1835 descripta) est species stellae marinae familiae asteriidarum.
Situs scientifici: • ITIS • NCBI • Biodiversity • Encyclopedia of Life • WoRMS: Marine Species 
Vide "Pisasterem ochraceum" apud Vicispecies. 
Haec stipula ad Echinodermatum spectat. Amplifica, si potes! Pisaster ochraceus (species ab Ioanne Friderico de Brandt anno 1835 descripta) est species stellae marinae familiae asteriidarum.
Pisaster ochraceus is een zeester uit de familie Asteriidae.
De wetenschappelijke naam van de soort werd in 1835 gepubliceerd door Johann Friedrich von Brandt.
Bronnen, noten en/of referenties
Wikimedia Commons'ta Pisaster ochraceus ile ilgili çoklu ortam belgeleri bulunur. 
Wikispecies'te Pisaster ochraceus ile ilgili detaylı taksonomi bilgileri bulunur. Pisaster ochraceus, Asteriidae familyasından, Pasifik Okyanusu'nda yaygın olarak görülen bir denizyıldızı türüdür. Kilittaşı türlerden biri olarak görülen Pisaster gelgit bölgesinin sağlığı konusunda önemli göstergelerden biridir.[1]
Bu denizyıldızının kolları 10 ila 25 cm arasında ve kalındır. Kollar, belirgin olmayan bir merkezi disk çevresinde dağılmıştır. Bireylerin çoğu mor renkli olmasına karşın turuncu, turuncu-toprak rengi, sarı, kızıl ya da kahverengi bireylerde görülür. Aboral (üst) yüzde, merkezi disk üzerinde beşgen şeklinde yayılmış çok sayıda küçük dikenler bulunur. Bu dikenler 2öö'den daha uzun değildir.[2][3] Pisaster cinsinde tüp ayakların ucunda yapışıcılar bulunur ve bunlar sayesinde kayalara tutunan denizyıldızı çok dalgalı alanlarda yaşayabilir.[4]
Aynı cinste olan ve beyaz ya da mor dikenlerinin çevresinde mavi halkalar bulunan Pisaster giganteus ile pembe renkli ve küçük beyaz dikenli Pisaster brevispinus türleri Pisaster ochraceus türü denizyıldızları ile karıştırılabilir. Bu iki türün aboral dikenlerinin ve renklerinin farklılığı türlerin ayırt edilmesini sağlar. Bazen Evasterias troscheli türü de Pisaster ochraceus ile karıştırılabilir. E. troschelli türü denizyıldızının merkezi diski daha küçüktür ve kolları daha uzundur.[3][5]
Pisaster ochraceus, Asteriidae familyasından, Pasifik Okyanusu'nda yaygın olarak görülen bir denizyıldızı türüdür. Kilittaşı türlerden biri olarak görülen Pisaster gelgit bölgesinin sağlığı konusunda önemli göstergelerden biridir.
Pisaster ochraceus hay Sao biển tía là một loài sao biển được tìm thấy ở các vùng nước Thái Bình Dương. Loài này có 5 cánh dài từ 10–50 cm. Các cánh sao nằm xung quanh một đãi không được phân định rõ. Trong khi phần lớn cá thể có màu tía, chúng có thể có màu cam, màu đất son, vàng, hơi đỏ hoặc nâu. Bề mặt xa miệng chứa các gai nhỏ (xương nhỏ) được sắp xếp theo một mô hình giống mạng lưới hoặc ngũ giác trên đĩa trung tâm. Các xương nhỏ không cao hơn2 mm.[2][3].
Bài viết về chủ đề sinh học này vẫn còn sơ khai. Bạn có thể giúp Wikipedia bằng cách mở rộng nội dung để bài được hoàn chỉnh hơn. Pisaster ochraceus hay Sao biển tía là một loài sao biển được tìm thấy ở các vùng nước Thái Bình Dương. Loài này có 5 cánh dài từ 10–50 cm. Các cánh sao nằm xung quanh một đãi không được phân định rõ. Trong khi phần lớn cá thể có màu tía, chúng có thể có màu cam, màu đất son, vàng, hơi đỏ hoặc nâu. Bề mặt xa miệng chứa các gai nhỏ (xương nhỏ) được sắp xếp theo một mô hình giống mạng lưới hoặc ngũ giác trên đĩa trung tâm. Các xương nhỏ không cao hơn2 mm..
赭色海星（學名：Pisaster ochraceus），又名紫色海星[2]，是一種在太平洋水域很常見的海星。作為一種关键种，赭色海星及其同屬物種被認為是潮間帶的健康指標[3]。
一般的海星只有四到六年的壽命，但赭色海星的壽命可長達20年[4]
자주불가사리(영어: purple sea star)는 태평양에 흔한 불가사리의 일종이다. 핵심종으로서, 조간대의 건강을 나타내는 중요 지표로 여겨진다.[2]
다리는 다섯 개이며, 각 다리의 길이는 10-25 센티미터로 자란다. 다리들을 지탱해주는 중심원반은 형태가 흐리멍덩하다. 대부분 개체가 자주색이지만, 주황색, 노란색, 빨간색, 갈색 개체들도 있다. 비경구면에는 이소골이라는 작은 등뼈가 촘촘히 나 있으며, 이것이 중심원반에 그물 같은 무늬를 만든다. 이소골 높이는 2 밀리미터 이하다.[3][4] 왕불가사리속의 불가사리들은 다리 말단에 흡반이 있어서 바위에 붙어 움직일 수 있으며, 파도가 강하게 드나드는 곳에 산다.[5] 자주불가사리는 간단한 신경계만 있을 뿐 뇌가 없다. 중심원반에 식도신경환이 있어서, 각 다리의 신경과 연결되어 신호를 중계한다.[6]
