Sea urchins or urchins are typically spiny, globular animals, echinoderms in the class Echinoidea. About 950 species live on the seabed, inhabiting all oceans and depth zones from the intertidal to 5,000 metres. Their tests are round and spiny, typically from 3 to 10 cm across. Sea urchins move slowly, crawling with their tube feet, and sometimes pushing themselves with their spines. They feed primarily on algae but also eat slow-moving or sessile animals. Their predators include sea otters, starfish, wolf eels, and triggerfish.
Diadema antillarum, also known as the lime urchin, black sea urchin, or the long-spined sea urchin, is a species of sea urchin in the family Diadematidae.
Echinus esculentus, the European edible sea urchin or common sea urchin, is a species of marine invertebrate in the Echinidae family. It is found in coastal areas of western Europe down to a depth of 1,200 m (3,900 ft). It is considered "Near threatened" in the IUCN Red List of Threatened Species.
Meoma ventricosa, known by the common names cake urchin and red heart urchin, is a large species of sea urchin which lives in shallow waters in the Caribbean. It may reach a diameter of twenty centimeters and is covered in reddish-brown spines. It has both pentagonal radial symmetry and bilateral symmetry, giving it a sand-dollar appearance; however, two of its five sections are merged more closely than the others.
Lytechinus variegatus, commonly called the green sea urchin or the variegated sea urchin, is a species of sea urchin that can be found in the warm waters of the western Atlantic Ocean and Caribbean Sea.
Echinus is a genus of sea urchins. Sea urchins are echinoderms that are typically spherical or flattened with a covering of spine-like structures. Sea urchins tend to be important members of their ecosystems by grazing on other organisms and stabilizing populations. In addition to this, sea urchins play a large role in different economies globally as the urchin themselves and their roe are sold for consumption. The same is true for the species within the genus Echinus.
Heterocentrotus mamillatus, commonly known as the slate pencil urchin, red slate pencil urchin, or red pencil urchin, is a species of tropical sea urchin from the Indo-Pacific region.
Tripneustes ventricosus, commonly called the West Indian sea egg or white sea urchin, is a species of sea urchin. It is common in the Caribbean Sea, the Bahamas and Florida and may be found at depths of less than 10 metres (33 ft).
Echinometra mathaei, the burrowing urchin, is a species of sea urchin in the family Echinometridae. It occurs in shallow waters in the Indo-Pacific region. The type locality is Mauritius.
Parborlasia corrugatus is a proboscis worm in the family Lineidae. It was formerly placed in family Cerebratulidae. This species of proboscis or ribbon worm can grow to 2 metres in length, and lives in marine environments down to 3,590 metres (11,780 ft). This scavenger and predator is widely distributed in cold southern oceans.
Odontaster validus is a species of sea star in the family Odontasteridae. Its range includes the Southern Ocean and the seas around the mainland and islands of Antarctica.
The Antarctic scallop is a species of bivalve mollusc in the large family of scallops, the Pectinidae. It was thought to be the only species in the genus Adamussium until an extinct Pliocene species was described in 2016. Its exact relationship to other members of the Pectinidae is unclear. It is found in the ice-cold seas surrounding Antarctica, sometimes at great depths.
Homaxinella balfourensis is a species of sea sponge in the family Suberitidae. It is found in the seas around Antarctica and can grow in two forms, either branching out in one plane like a fan or forming an upright club-like structure.
Aspidodiadema jacobyi is a small sea urchin in the family Aspidodiadematidae. It lives in tropical seas at great depths. Aspidodiadema jacobyi was first scientifically described in 1880 by Alexander Emanuel Agassiz, an American scientist.
Echinometra viridis, the reef urchin, is a species of sea urchin in the family Echinometridae. It is found on reefs in very shallow parts of the western Atlantic Ocean and the Caribbean Sea.
Cidaris cidaris is a species of sea urchin commonly known as the long-spine slate pen sea urchin. It is found in deep water in the eastern Atlantic Ocean and the Mediterranean Sea.
The emerald rockcod, also known as the emerald notothen is a species of marine ray-finned fish belonging to the family Nototheniidae, the notothens or cod icefishes. It is native to the Southern Ocean where it is a commercially important species.
Pseudocentrotus depressus, commonly known as the pink sea urchin, is a species of sea urchin, one of only two species in the genus Pseudocentrotus. It was first described in 1864 by the American marine zoologist Alexander Agassiz as Toxocidaris depressus, having been collected during the North Pacific Exploring and Surveying Expedition undertaken by Captain Cadwalader Ringgold and later Captain John Rodgers.
Isotealia antarctica, the salmon anemone, is a species of sea anemone in the family Actiniidae. It is found in the southern Atlantic and Pacific Oceans and the waters around Antarctica. It is a filter feeder and opportunistic predator.
Tritoniella is a genus of sea slugs, specifically dendronotid nudibranchs. It is a marine gastropod mollusc in the family Tritoniidae.The genus was described in 1907 by the British diplomat and malacologist Charles Eliot.
