Loxechinus | |
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Two Loxechinus albus | |
Scientific classification ![]() | |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Echinoidea |
Order: | Camarodonta |
Family: | Parechinidae |
Genus: | Loxechinus Desor, 1856 |
Species: | L. albus |
Binomial name | |
Loxechinus albus | |
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. [2] It is the only species in the genus Loxechinus. [3] 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 (although it is the most common and widespread large sea urchins in that country). L. albus is found on rocky reefs and shores in the intertidal and subtidal zones to a depth of 340 m (1,120 ft). [4]
Loxechinus albus is a fast-growing, relatively large sea urchin with a test diameter of up to 11 cm (4.3 in), although the far southernmost populations tend to grow slower and reach a smaller size. [2] The test is dorsoventrally flattened and densely covered in small spines. [5] Living individuals of this urchin typically appear overall dull reddish with some pale green to the spines, but its color is variable, [4] and some large specimens have been found in deeper waters which are white. [5] There are 6 to 11 ambulacral plates each bearing a single short primary spine and many longer secondaries. The globiferous pedicellariae have a neck between the stem and head, large valves and several lateral teeth. [5]
Loxechinus albus is mostly found on rocky coasts associated with the kelp Macrocystis pyrifera . It is more numerous in exposed locations. It is a herbivore and seems to feed on whatever species of alga grow nearby. Juveniles feed on crustose coralline algae, diatoms and algal detritus. In the Northern Hemisphere, some urchin species have large population swings and may create "barren ground" around them. In contrast, L. albus seems to be in balance with its food supply and does not seem to be limited by the quantity of algae available nor does the kelp growth become excessive. This may be partly because it also feeds on drifting algal fragments which are always abundant in kelp beds. [6]
The spawning period varies along the Chilean coast. Spawning period occurs later in the year as latitude increases; at 23° S it occurs in June, at 45° S (Chiloé) it occurs in November–December. The populations inhabiting the Magellan Region ( 53° S) are an exception since their spawning period lasts from July to September. [5]
The echinopluteus larvae form part of the zooplankton for about thirty days, feeding on phytoplankton. They settle in the rocky intertidal zone and undergo metamorphosis, living in cracks in the rocks as juveniles before migrating to the neritic zone where they mostly feed on drift algae and fronds of kelp. [6]
Known locally in Chile as the 'Erizo rojo' (red urchin), it is harvested commercially by fishermen and is an ingredient in Chilean cuisine. Over-exploitation, its conspicuousness and lack of official harvest control means that this urchin is relatively rare in some parts of its range. It takes 8 years to reach harvestable size. [5]
Sea urchins are spiny, globular echinoderms in the class Echinoidea. About 950 species of sea urchin live on the seabed of every ocean and inhabit every depth zone from the intertidal seashore down to 5,000 meters. The spherical, hard shells (tests) of sea urchins are round and spiny, ranging in diameter from 3 to 10 cm. Sea urchins move slowly, crawling with tube feet, and also propel themselves with their spines. Although algae are the primary diet, sea urchins also eat slow-moving (sessile) animals. Predators that eat sea urchins include a wide variety of fish, starfish, crabs, marine mammals. Sea urchins are also used as food especially in Japan.
Haliotis cracherodii, the black abalone, is a species of large edible sea snail, a marine gastropod mollusk in the family Haliotidae, the abalones.
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.
Macrocystis is a monospecific genus of kelp. This genus contains the largest of all the phaeophyceae or brown algae. Macrocystis has pneumatocysts at the base of its blades. Sporophytes are perennial and the individual may live for up to three years; stipes/fronds within a whole individual undergo senescence, where each frond may persist for approximately 100 days. The genus is found widely in subtropical, temperate, and sub-Antarctic oceans of the Southern Hemisphere and in the northeast Pacific from Baja California to Sitka, Alaska. Macrocystis is often a major component of temperate kelp forests.
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.
Kina is a sea urchin endemic to New Zealand. This echinoderm belongs to the family Echinometridae and it can reach a maximum diameter of 16–17 cm.
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.
Macrocystis pyrifera, commonly known as giant kelp or bladder kelp, is a species of kelp, and one of four species in the genus Macrocystis. Despite its appearance, it is not a plant; it is a heterokont. Giant kelp is common along the coast of the northeastern Pacific Ocean, from Baja California north to southeast Alaska, and is also found in the southern oceans near South America, South Africa, Australia, and New Zealand. Individual algae may grow to more than 45 metres long at a rate of as much as 60 cm (2 ft) per day. Giant kelp grows in dense stands known as kelp forests, which are home to many marine animals that depend on the algae for food or shelter. The primary commercial product obtained from giant kelp is alginate, but humans also harvest this species on a limited basis for use directly as food, as it is rich in iodine, potassium, and other minerals. It can be used in cooking in many of the ways other sea vegetables are used, and particularly serves to add flavor to bean dishes.
Dendraster excentricus, also known as the eccentric sand dollar, sea-cake, biscuit-urchin, western sand dollar, or Pacific sand dollar, is a species of sand dollar in the family Dendrasteridae. It is a flattened, burrowing sea urchin found in the north-eastern Pacific Ocean from Alaska to Baja California.
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.
Phormosoma placenta is a species of sea urchin in the order Echinothurioida. It is a deepwater species, seldom being found at depths less than 500 m (1,600 ft), and occurs on either side of the Atlantic Ocean on the continental slope.
Diadema savignyi is a species of long-spined sea urchin belonging to the family Diadematidae. Common names include long-spined sea urchin, black longspine urchin and the banded diadem. It is native to the east coast of Africa, the Red Sea, the Indian Ocean and western Pacific Ocean. It was first described in 1829 by the French naturalist Jean Victoire Audouin. The specific epithet honours the French zoologist Marie Jules César Savigny who described many new marine species from the Mediterranean Sea and Red Sea. The type locality is Mauritius.
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.
Tetrapygus is a genus of sea urchins in the family Arbaciidae. It is a monotypic genus and the only species is Tetrapygus niger which was first described by the Chilean naturalist Juan Ignacio Molina in 1782. 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
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.
Acanthopleura echinata is a Southeast Pacific species of edible chiton, a marine polyplacophoran mollusc in the family Chitonidae, the typical chitons.
Parechinus angulosus, the Cape urchin, is a sea urchin in the family Parechinidae endemic to southern Africa.