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.
Davidson Seamount is a seamount located off the coast of Central California, 80 mi (129 km) southwest of Monterey and 75 mi (121 km) west of San Simeon. At 26 mi (42 km) long and 8 mi (13 km) wide, it is one of the largest known seamounts in the world. From base to crest, the seamount is 7,480 ft (2,280 m) tall, yet its summit is still 4,101 ft (1,250 m) below the sea surface. The seamount is biologically diverse, with 237 species and 27 types of deep-sea coral having been identified.
The Brisingids are deep-sea-dwelling starfish in the order Brisingida.
Psilaster andromeda is a species of starfish in the family Astropectinidae. It is native to the northeastern Atlantic Ocean where it occurs at abyssal depths.
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.
Hippasteria is one of 70 genera of sea stars in the diverse family Goniasteridae.
Fromia is a genus of starfish belonging to the family Goniasteridae.
Cryptasterina hystera is a species of starfish. It is found in a limited region of the coast of Australia and is very similar in appearance to Cryptasterina pentagona. The two appear to have diverged from a common ancestral line a few thousand years ago.
Poraniidae is a family of starfishes in the order Valvatida.
Poraniopsis inflata, the spiny sea star, is a species of starfish in the family Poraniidae. It is native to the Pacific Ocean and is found in deep water off the coast of North America.
Trophodiscus almus is a species of starfish in the family Astropectinidae. It is found in fairly deep waters in the Sea of Okhotsk, the Sea of Japan and around the Japanese island of Hokkaido. It is very unusual among starfish in that it broods its young on its upper surface. Its common name in Japanese is "Komochi-momiji".
Clavaporania fitchorum is a species of starfish in the family Poraniidae. It is the only known species of the genus Clavaporania. It is native to the South Pacific Ocean and is found in deep water off the coast of Australia.
Apollonaster is a genus of abyssal sea stars in the family Goniasteridae. They can be identified by their bare abactinal plate surfaces and multiple accessory granule rows on their abactinal plates. To date, Apollonaster has been found in the tropical Atlantic region and Hawaiian Islands region oceans, with no other locations or species being known as of 2015.
Hippasteria muscipula is one of twelve species of deep-sea sea star in the genus Hippasteria, which is in the family Goniasteridae.
Luidia magellanica is a species of starfish in the family Luidiidae. It is found in the southeastern Pacific Ocean on the coast of South America.
Meyenaster is a genus of starfish in the family Asteriidae. It is a monotypic genus and the only species is Meyenaster gelatinosus which was first described by the Prussian botanist and zoologist Franz Julius Ferdinand Meyen in 1834. It is found in the southeastern Pacific Ocean on the coasts of South America.
Anasterias antarctica, commonly called the Cinderella starfish, is a species of starfish in the family Asteriidae. It is found in coastal waters in the Southern Ocean and around Antarctica.
Asterias rathbuni is a starfish native to the Pacific coasts of Alaska in the United States and Far East Russia. There are two subspecies.
Helen Elizabeth Shearburn Rotman was a New Zealand expert on echinoderms, specifically starfish.
Rathbunaster is a monospecific genus of sea stars in the family Asteriidae. The genus name was given by Walter Kenrick Fisher to honor the starfish biologist Richard Rathbun of the Smithsonian Institution. He originally ranged this genus under the family Pycnopididae, synonymous with Asteriidae.
