| Pteraster tesselatus | |
|---|---|
 | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Asteroidea |
| Order: | Velatida |
| Family: | Pterasteridae |
| Genus: | Pteraster |
| Species: | P. tesselatus |
| Binomial name | |
| Pteraster tesselatus Ives, 1888 [1] | |
| Synonyms [1] | |
| |
Pteraster tesselatus, the slime star or cushion star, is a species of starfish in the family Pterasteridae found in the North Pacific.
The slime star's body has a wide central disc and five stumpy arms with upturned tips. It grows to a diameter of about 15 cm (5.9 in) and has an inflated appearance as the entire aboral (upper) surface is covered by a thick, raised, fleshy membrane. This has a smooth soft texture and is pale brown, grey, red, or orange, often with a symmetrical darker pattern. It conceals the madreporite and scales on the aboral surface proper and the gap underneath it is filled with a spongy tissue. A central pore in this membrane allows for water movement. [2] [3] The arms have rows of fan-shaped groups of five to seven spines between which are two rows of tube feet. The red eyespot is surrounded by spines at the apex of each arm. [4]
The slime star occurs in rocky areas on the west coast of North America from the Bering Sea southwards to central California at depths to 950 m (3,120 ft). [2] It is also known from the Aleutian Islands and Japan. [1] It is usually found in places where the current is strong. [4]
The slime star feeds on various benthic invertebrates, including the breadcrumb sponge (Halichondria panicea), the false jingle shell (Pododesmus macroschisma), other scallops and clams, and colonial sea squirts such as Aplidium and Didemnum species. It also feeds on the bacterial film that grows on the surface of mussels. [4] If attacked by a predator such as the morning sun star (Solaster dawsoni) or the sunflower star (Pycnopodia helianthoides), the slime star emits great quantities of repellent mucus and can often evade the predator. [3] The mucus is toxic and has been shown to kill other invertebrates immersed in it. [3]
The slime star breeds in the summer, with a female releasing a small number of eggs into the water. Nearby males then release sperm and the fertilised eggs rise to the surface of the water. They are bright orange or yellow and are wrapped in a gelatinous membrane. They become planktonic and pass through several developmental stages over the course of about 25 days. They then undergo metamorphosis into juvenile starfish and settle onto the seabed. [3] [4]
One of several different species of polychaete worms often lives symbiotically within the ambulacral grooves on the oral (under) surface of the slime star. [4]
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 6,000 m (20,000 ft) below the surface.
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 common starfish, common sea star or sugar starfish is the most common and familiar starfish in the north-east Atlantic. Belonging to the family Asteriidae, it has five arms and usually grows to between 10–30 cm across, although larger specimens are known. The common starfish is usually orange or brownish in color, and sometimes violet; specimens found in deeper waters are pale. The common starfish is found on rocky and gravelly substrates where it feeds on mollusks and other benthic invertebrates.
Ceramaster patagonicus, the cookie star, is a species of sea star. It is bright orange or yellow in colour. Its arms are short and it has no spines. It is a deep water species and lives on rocky sea beds. Its diet includes sponges.
The leather star is a sea star in the family Asteropseidae found at depths to 100 m (328 ft) off the western seaboard of North America. It was first described to science by Adolph Eduard Grube in 1857.
Leptasterias hexactis is a species of starfish in the family Asteriidae, commonly known as the six-rayed star. It is found in the intertidal zone of the western seaboard of the United States. It is a predator and is unusual among starfish in that it broods its eggs and young.
Solaster dawsoni, the morning sun star, is a species of starfish in the family Solasteridae. It is found on either side of the northern Pacific Ocean. It has two subspecies:
The purple sunstar, northern sunstar, or smooth sun star, Solaster endeca, is a species of starfish 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.
Anasterias rupicola is a species of starfish in the family Asteriidae. It is found in shallow waters in the Southern Ocean and sub-Antarctic Indian Ocean.
Labidiaster annulatus, the Antarctic sun starfish or wolftrap starfish is a species of starfish in the family Heliasteridae. It is found in the cold waters around Antarctica and has a large number of slender, flexible rays.
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.
Orthasterias is a genus of sea stars in the family Asteriidae. Orthasterias koehleri, the rainbow star or red-banded sea star, is the only species in the genus. It is found in the North Pacific Ocean.
The orange knobby star, Echinaster echinophorus, is a species of sea star found in the Caribbean Sea and along the Atlantic coast of South America.
Echinaster spinulosus, the small spine sea star, is a species of sea star found in shallow parts of the western Atlantic Ocean, the Caribbean Sea and Gulf of Mexico.
The spiny sand seastar is a species of starfish in the family Luidiidae. It is found in shallow parts of the China Sea and in the vicinity of the Korean archipelago. The tissues of this starfish have been found to contain several secondary metabolites with medicinal potential.
Astropecten armatus, the spiny sand star or Estrella de Arena, is a sea star in the family Astropectinidae. It is found on sandy or gravelly areas in the East Pacific ranging from California (USA) to Ecuador.
Pteraster militaris, the wrinkled star, is a species of starfish in the family Pterasteridae. It is found in the northern Pacific Ocean, the Arctic Ocean, the Barents Sea, and the northern Atlantic Ocean.
Astropecten duplicatus, the two-spined sea star, is a starfish in the family Astropectinidae. It is found in the eastern Atlantic Ocean, the Caribbean Sea and the Gulf of Mexico.
Neoferdina cumingi, also known as Cuming's sea star, is a species of starfish in the family Goniasteridae. It is native to the tropical Indo-Pacific region.