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.
Kelp forests are underwater areas with a high density of kelp, which covers a large part of the world's coastlines. Smaller areas of anchored kelp are called kelp beds. They are recognized as one of the most productive and dynamic ecosystems on Earth. Although algal kelp forest combined with coral reefs only cover 0.1% of Earth's total surface, they account for 0.9% of global primary productivity. Kelp forests occur worldwide throughout temperate and polar coastal oceans. In 2007, kelp forests were also discovered in tropical waters near Ecuador.
The red sea urchin is a sea urchin found in the northeastern Pacific Ocean from Alaska to Baja California. It lives in shallow waters from the low-tide line to greater than 280 m (920 ft) deep, and is typically found on rocky shores sheltered from extreme wave action in areas where kelp is available.
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.
Loxechinus albus is an echinoderm of the family Parechinidae, native to coastal southern South America, ranging from Ecuador, along the entire coasts of Peru and Chile, to Argentina, as well as the Falkland Islands. It is the only species in the genus Loxechinus. It is known as the Chilean sea urchin or red sea urchin, but the latter name is typically used for the North Pacific Mesocentrotus franciscanus and it is not the only species of sea urchin in Chile. L. albus is found on rocky reefs and shores in the intertidal and subtidal zones to a depth of 340 m (1,120 ft).
Hemicentrotus pulcherrimus is a species of sea urchin, the only one in the monotypic genus Hemicentrotus. It was first described by the American engineer and marine zoologist Alexander Agassiz in 1864 as Psammechinus pulcherrimus. Its range extends along the coasts of Korea, Taiwan and China, and in Japan from Kyūshū to Ishikari Bay. An edible species, it is harvested from Kyūshū to Fukui, in the Sea of Japan.
Pterygophora californica is a large species of kelp, commonly known as stalked kelp. It is the only species in its genus Pterygophora. It grows in shallow water on the Pacific coast of North America where it forms part of a biodiverse community in a "kelp forest". It is sometimes also referred to as woody-stemmed kelp, walking kelp, or winged kelp.
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.
Diadema mexicanum is a species of long-spined sea urchin belonging to the family Diadematidae. It is native to the Pacific coast of Mexico, Costa Rica, El Salvador, Nicaragua and Panama.
Asterodiscides truncatus, the firebrick starfish, is a species of five-armed starfish in the family Asterodiscididae. It is native to eastern and southern Australia, the Norfolk Ridge and the Kermadec Islands of New Zealand.
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.
Patiria chilensis is a species of starfish in the family Asterinidae. It is found in the southeastern Pacific Ocean along the coasts of South America. It is a broadly pentagonal, cushion-like starfish with five short arms.
Stichaster striatus, the common light striated star, is a species of starfish in the family Stichasteridae, found in the southeastern Pacific Ocean. It was first described by the German zoologists Johannes Peter Müller and Franz Hermann Troschel in 1840.
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.
Lessonia trabeculata is a species of kelp, a brown alga in the genus Lessonia. It grows subtidally off the coasts of Peru and northern and central Chile, with the closely related Lessonia nigrescens tending to form a separate zone intertidally. Lessonia trabeculata kelp have gained a great economic importance for alginate production, and its harvest has greatly intensified along the Chilean coast during past two decades
Medialuna ancietae is a species of sea chub native to the Pacific coast of South America where it inhabits the giant kelp forests. It is known locally as acha, mero del sur or chino.
Lytechinus pictus, commonly known as the painted urchin, is a sea urchin in the family Toxopneustidae. It occurs on shallow reefs in the tropical and subtropical eastern Pacific Ocean, off the coasts of California, Central America and South America as far south as Ecuador.
Doryteuthis gahi, also known as the Patagonian longfin squid and Patagonian squid, is a small-sized squid belonging to the family Loliginidae. It occurs in coastal waters in the southeastern Pacific Ocean and the southwestern Atlantic Ocean where it is caught and eaten for food.
Aplodactylus punctatus, the Zamba marblefish, is a species of marine ray finned fish, one of the marblefishes belonging to the family Aplodactylidae. It is found in the eastern Pacific Ocean of the west coast of South America.
