text:
Sea urchin
From Wikipedia, the free encyclopedia
Jump to: navigation, search
For other uses, see Sea urchin (disambiguation).
Sea urchin
Temporal range: Ordovician–Present
PreЄ
Є
O
S
D
C
P
T
J
K
Pg
N
Tripneustes ventricosus and Echinometra viridis,
two species of tropical sea urchins.
Scientific classification
Kingdom: Animalia
Phylum: Echinodermata
Subphylum: Echinozoa
Class: Echinoidea
Leske, 1778
Subclasses
Subclass Perischoechinoidea
Order Cidaroida (pencil urchins)
Subclass Euechinoidea
Superorder Atelostomata
Order Cassiduloida
Order Spatangoida (heart urchins)
Superorder Diadematacea
Order Diadematoida
Order Echinothurioida
Order Pedinoida
Superorder Echinacea
Order Arbacioida
Order Echinoida
Order Phymosomatoida
Order Salenioida
Order Temnopleuroida
Superorder Gnathostomata
Order Clypeasteroida (sand dollars)
Order Holectypoida
Sea urchins or urchins (/ˈɜːrtʃɪnz/) are spiny, globular animals, echinoderms in the class Echinoidea. About 950 species inhabit all oceans, and zones from the intertidal to 5,000 metres (16,000 ft; 2,700 fathoms) deep.[1] Their tests (hard shells) are round and spiny, typically from 3 to 10 cm (1.2 to 3.9 in) across. Sea urchins move slowly, crawling with their tube feet, and defended by their sharp spines, which are sometimes toxic. They feed primarily on algae but also eat slow-moving or sessile animals. Their predators include sea otters, starfish, wolf eels, and triggerfish. The name "urchin" is an old word for hedgehog, which sea urchins resemble; they have archaically been called sea hedgehogs.[2][3] The name is derived from Old French herichun, from Latin ericius, hedgehog.[4]
Like other echinoderms, urchins have fivefold symmetry as adults, but their pluteus larvae have bilateral (mirror) symmetry, indicating that they belong to the Bilateria, the large group of animal phyla that includes chordates, arthropods, annelids and molluscs. They are widely distributed across all the oceans, all climates from tropical to polar, and inhabit most marine habitats from rocky shores to hadal zone depths. Echinoids have a rich fossil record dating back to the Ordovician, some 450 million years ago. Their closest relatives are the sea cucumbers (Holothuroidea) among the echinoderms, which are deuterostomes, along with the chordates.
Humans often notice sea urchins when swimmers are injured by the animals' sharp and sometimes poisonous spines. The animals have been studied since the 19th century as model organisms in developmental biology, as their embryos were easy to observe; this has continued with studies of their genomes because of their unusual fivefold symmetry and relationship to chordates. Species such as the slate pencil urchin are popular in aquariums, where they are useful for controlling algae. Fossil urchins have been used as protective amulets.
Contents
[hide]
1 Diversity
2 Description
3 Systems
3.1 Musculoskeletal
3.2 Feeding and digestion
3.3 Circulation and respiration
3.4 Nervous system and senses
4 Life history
4.1 Reproduction
4.2 Development
4.3 Life cycle and development
5 Ecology
5.1 Trophic level
5.2 Predators, parasites, and diseases
5.3 Anti-predator defences
5.4 Range and habitat
6 Evolution
6.1 Fossil history
6.2 Phylogeny
6.2.1 External
6.2.2 Internal
7 Relation to humans
7.1 Injuries
7.2 Science
7.3 As food
7.4 Aquaria
7.5 Folklore
8 See also
9 Notes
10 References
11 External links
Diversity[edit]
See also: List of echinodermata orders
Sea urchins are members of the phylum Echinodermata, which also includes sea stars, sea cucumbers, brittle stars, and crinoids. Like other echinoderms, they have five-fold symmetry (called pentamerism) and move by means of hundreds of tiny, transparent, adhesive "tube feet". The symmetry is not obvious in the living animal, but is easily visible in the dried test.
Specifically, the term "sea urchin" refers to the "regular echinoids", which are symmetrical and globular, and includes several different taxonomic groups, including two subclasses : Euechinoidea ("modern" sea urchins, including irregular ones) and Cidaroidea or "slate-pencil urchins", which have very thick, blunt spines, with algae and sponges growing on it. The irregular sea urchins are an infra-class inside the Euechinoidea, called Irregularia, and include Atelostomata and Neognathostomata. "Irregular" echinoids include: flattened sand dollars, sea biscuits, and heart urchins.[5]
Together with sea cucumbers (Holothuroidea), they make up the subphylum Echinozoa, which is characterized by a globoid shape without arms or projecting rays. Sea cucumbers and the irregular echinoids have secondarily evolved diverse shapes. Although many sea cucumbers have branched tentacles surrounding their oral openings, these have originated from modified tube feet and are not homologous to the arms of the crinoids, sea stars, and brittle stars.
Paracentrotus lividus, a regular sea urchin (Euechinoidea, infraclass Carinacea).
A sand dollar, an irregular sea urchin (Irregularia).
Phyllacanthus imperialis, a cidaroid sea urchin (Cidaroidea).
Description[edit]
Sea urchin anatomy based on Arbacia sp.
Urchins typically range in size from 6 to 12 cm (2.4 to 4.7 in), although the largest species can reach up to 36 cm (14 in).[6] They have a rigid, usually spherical body bearing moveable spines, which gives the class the name Echinoidea (from the Greek ekhinos, spine).[7]
Like other echinoderms, sea urchin early larvae have bilateral symmetry,[8] but they develop five-fold symmetry as they mature. This is most apparent in the "regular" sea urchins, which have roughly spherical bodies with five equally sized parts radiating out from their central axes. The mouth is at the base of the animal and the anus at the top; the lower surface is described as "oral" and the upper surface as "aboral".[a][9]
Several sea urchins, however, including the sand dollars, are oval in shape, with distinct front and rear ends, giving them a degree of bilateral symmetry. In these urchins, the upper surface of the body is slightly domed, but the underside is flat, while the sides are devoid of tube feet. This "irregular" body form has evolved to allow the animals to burrow through sand or other soft materials.[6]
Systems[edit]
Musculoskeletal[edit]
Tube feet of a purple sea urchin
Further information: Test (biology) and Tube feet
At first glance, sea urchins often appear incapable of moving. Sometimes, the most visible life sign is the spines, which attach to ball-and-socket joints and can point in any direction. In most urchins, touch elicits a prompt reaction from the spines, which converge toward the touch point. Sea urchins have no visible eyes, legs, or means of propulsion, but can move freely over hard surfaces using adhesive tube feet, working in conjunction with the spines.[9]
The internal organs are enclosed in a hard shell or test composed of fused plates of calcium carbonate covered by a thin dermis and epidermis. The test is rigid, and divides into five ambulacral grooves separated by five interambulacral areas. Each of these areas consists of two rows of plates, so the sea urchin test includes 20 rows of plates in total. The plates are covered in rounded tubercles which contain the sockets to which the spines are attached by ball and socket joints. The inner surface of the test is lined by peritoneum.[6] Sea urchins convert aqueous carbon dioxide using a catalytic process involving nickel into the calcium carbonate portion of the test.[10] Sea urchins lack the layer of muscle that allows other echinoderms to move their arms.
Most species have two series of spine, primary (long) and secondary (short), distributed over the surface of the body with the shortest at the poles and the longest at the equator. The spines are usually hollow and cylindrical. Contraction of the muscular sheath that covers the test causes the spine to lean in one direction or another, while an inner sheath of collagen fibres can reversibly change from soft to rigid which can lock the spine in one position. Located among the spines are several types of pedicellaria, moveable stalked structures with jaws.[9]
Sea urchins move by walking using their many flexible tube feet in a similar way to starfish; Regular sea urchins don't have any favourite walking direction.[11] The tube feet protrude through pairs of pores in the test, and are operated by a water vascular system which works through hydraulic pressure, allowing the sea urchin to pump water into and out of the tube feet. In locomotion, the tube feet are assisted by the spines which can be used for pushing or to lift the test off the substrate. Movement is generally related to feeding, with the red sea urchin (Mesocentrotus franciscanus) managing about 7.5 cm (3 in) a day when there is ample food, and up to 50 cm (20 in) a day where there is not. An inverted sea urchin can right itself by progressively attaching and detaching its tube feet and manipulating its spines to roll its body upright.[9] Some species bury themselves in soft sediment using their spines, and Paracentrotus lividus uses its jaws to burrow into soft rocks.[12]
Test of an Echinus esculentus, a regular sea urchin
Test of an Echinodiscus tenuissimus, an irregular sea urchin ("sand dollar")
Test of a Phyllacanthus imperialis, a cidaroid sea urchin. These are characterised by their big tubercles, bearing large radiola
Close-up of the test showing an ambulacral groove with its two rows of pore-pairs, between two interambulacra areas (green). The tubercles are non perforated.
Close-up on a cidaroid sea urchin apical disc : the 5 holes are the gonopores, and the central one is the anus ("periproct"). The biggest genital plate is the madreporite.
Feeding and digestion[edit]
The mouth lies in the centre of the oral surface in regular urchins, or towards one end in irregular urchins. It is surrounded by lips of softer tissue, with numerous small, embedded bony pieces. This area, called the peristome, also includes five pairs of modified tube feet and, in many species, five pairs of gills.[6] The jaw apparatus consists of five strong arrow-shaped plates known as pyramids, the ventral surface of each of which has a toothband with a hard tooth pointing towards the centre of the mouth. Specialised muscles control the protrusion of the apparatus and the action of the teeth, and the animal can grasp, scrape, pull and tear.[9] The structure of the mouth and teeth have been found to be so efficient at grasping and grinding that their structure has been tested for use in real-world applications.[13]
On the upper surface of the test at the aboral pole is a membrane, the periproct, which surrounds the anus. The periproct contains a variable number of hard plates, five of which, the genital plates, contain the gonopores, and one is modified to contain the madreporite, which is used to balance the water vascular system.[9]
Aristotle's lantern in a sea urchin, viewed in lateral section
The mouth of most sea urchins is made up of five calcium carbonate teeth or jaws, with a fleshy, tongue-like structure within. The entire chewing organ is known as Aristotle's lantern from Aristotle's description in his History of Animals.
…the urchin has what we mainly call its head and mouth down below, and a place for the issue of the residuum up above. The urchin has, also, five hollow teeth inside, and in the middle of these teeth a fleshy substance serving the office of a tongue. Next to this comes the esophagus, and then the stomach, divided into five parts, and filled with excretion, all the five parts uniting at the anal vent, where the shell is perforated for an outlet... In reality the mouth-apparatus of the urchin is continuous from one end to the other, but to outward appearance it is not so, but looks like a horn lantern with the panes of horn left out. (Tr. D'Arcy Thompson)
However, this has recently been proven to be a mistranslation. Aristotle's lantern is actually referring to the whole shape of sea urchins, which look like the ancient lamps of Aristotle's time.[14][15]
Heart urchins are unusual in not having a lantern. Instead, the mouth is surrounded by cilia that pull strings of mucus containing food particles towards a series of grooves around the mouth.[6]
Digestive and circulatory systems of a regular sea urchin:
a = anus ; m = madreporite ; s = aquifer canal ; r = radial canal ; p = podial ampulla ; k = test wall ; i = intestine ; b = mouth
The lantern, where present, surrounds both the mouth cavity and the pharynx. At the top of the lantern, the pharynx opens into the esophagus, which runs back down the outside of the lantern, to join the small intestine and a single caecum. The small intestine runs in a full circle around the inside of the test, before joining the large intestine, which completes another circuit in the opposite direction. From the large intestine, a rectum ascends towards the anus. Despite the names, the small and large intestines of sea urchins are in no way homologous to the similarly named structures in vertebrates.[6]
Digestion occurs in the intestine, with the caecum producing further digestive enzymes. An additional tube, called the siphon, runs beside much of the intestine, opening into it at both ends. It may be involved in resorption of water from food.[6]
Circulation and respiration[edit]
The water vascular system leads downwards from the madreporite through the slender stone canal to the ring canal, which encircles the oesophagus. Radial canals lead from her through each ambulacral area to terminate in a small tentacle which passes through the abulacral plate near the aboral pole. Lateral canals lead from these radial canals, ending in ampullae. From here, two tubes pass through a pair of pores on the plate to terminate in the tube feet.[9]
Sea urchins possess a hemal system with a complex network of vessels in the mesenteries around the gut, but little is known of the functioning of this system.[9] However, the main circulatory fluid fills the general body cavity, or coelom. This coelomic fluid contains phagocytic coelomocytes, which move through the vascular and hemal systems and are involved in internal transport and gas exchange. The coelomocytes are an essential part of blood clotting, but also collect waste products and actively remove them from the body through the gills and tube feet.[6]
Most sea urchins possess five pairs of external gills attached to the peristomial membrane around their mouths. These thin-walled projections of the body cavity are the main organs of respiration in those urchins that possess them. Fluid can be pumped through the gills' interiors by muscles associated with the lantern, but this is not continuous, and occurs only when the animal is low on oxygen. Tube feet can also act as respiratory organs, and are the primary sites of gas exchange in heart urchins and sand dollars, both of which lack gills. The inside of each tube foot is divided by a septum which reduces diffusion between the incoming and outgoing streams of fluid.[9]
Diadema setosum
Nervous system and senses[edit]
The nervous system of sea urchins has a relatively simple layout. With no true brain, the neural center is a large nerve ring encircling the mouth just inside the lantern. From the nerve ring, five nerves radiate underneath the radial canals of the water vascular system, and branch into numerous finer nerves to innervate the tube feet, spines, and pedicellariae.[6]
Sea urchins are sensitive to touch, light, and chemicals. There are numerous sensitive cells in the epithelium, especially in the spines, pedicellaria and tube feet, and around the mouth.[9] Although they do not have eyes or eye spots (except for diadematids, which can follow a threat with their spines), the entire body of most regular sea urchins might function as a compound eye.[16] In general, sea urchins are negatively attracted to light, and seek to hide themselves in crevices or under objects. Most species, apart from pencil urchins, have statocysts in globular organs called spheridia. These are stalked structures and are located within the ambulacral areas; their function is to help in gravitational orientation.[6]
Life history[edit]
Reproduction[edit]
Play media
Male flower urchin (Toxopneustes roseus) releasing milt, November 1, 2011, Lalo Cove, Sea of Cortez
Sea urchins are dioecious, having separate male and female sexes, although no distinguishing features are visible externally. Regular sea urchins have five gonads, lying underneath the interambulacral regions of the test, while the irregular forms mostly have four, with the hindmost gonad being absent; heart urchins have three or two. Each gonad has a single duct rising from the upper pole to open at a gonopore lying in one of the genital plates surrounding the anus. Some burrowing sand dollars have an elongated papilla that enables the liberation of gametes above the surface of the sediment.[9] The gonads are lined with muscles underneath the peritoneum, and these allow the animal to squeeze its gametes through the duct and into the surrounding sea water, where fertilization takes place.[6]
Development[edit]
Sea urchin blastula
During early development, the sea urchin embryo undergoes 10 cycles of cell division,[17] resulting in a single epithelial layer enveloping the blastocoel. The embryo then begins gastrulation, a multipart process which dramatically rearranges its structure by invagination to produce the three germ layers, involving an epithelial-mesenchymal transition; primary mesenchyme cells move into the blastocoel[18] and become mesoderm.[19]
The development of a regular sea urchin
An unusual feature of sea urchin development is the replacement of the larva's bilateral symmetry by the adult's broadly fivefold symmetry. During cleavage, mesoderm and small micromeres are specified. At the end of gastrulation, cells of these two types form coelomic pouches. In the larval stages, the adult rudiment grows from the left coelomic pouch; after metamorphosis, that rudiment grows to become the adult. The animal-vegetal axis is established before the egg is fertilized. The oral-aboral axis is specified early in cleavage, and the left-right axis appears at the late gastrula stage.[20]
Life cycle and development[edit]
Pluteus larva has bilateral symmetry.
In most cases, the female's eggs float freely in the sea, but some species hold onto them with their spines, affording them a greater degree of protection. The unfertilized egg meets with the free-floating sperm released by males, and develops into a free-swimming blastula embryo in as few as 12 hours. Initially a simple ball of cells, the blastula soon transforms into a cone-shaped echinopluteus larva. In most species, this larva has 12 elongated arms lined with bands of cilia that capture food particles and transport them to the mouth. In a few species, the blastula contains supplies of nutrient yolk and lacks arms, since it has no need to feed.[6]
Several months are needed for the larva to complete its development, the change into the adult form beginning with the formation of test plates in a juvenile rudiment which develops on the left side of the larva, its axis being perpendicular to that of the larva. Soon, the larva sinks to the bottom and metamorphoses into a juvenile urchin in as little as one hour.[9] In some species, adults reach their maximum size in about five years.[6] The purple urchin becomes sexually mature in two years and may live for twenty.[21]
Ecology[edit]
Trophic level[edit]
Play media
Living sea urchin in natural habitat video
Sea urchins feed mainly on algae, so they are primarily herbivores, but can feed on sea cucumbers and a wide range of invertebrates, such as mussels, polychaetes, sponges, brittle stars, and crinoids, making them omnivores, consumers at a range of trophic levels.[22]
Predators, parasites, and diseases[edit]
Mass mortality of sea urchins was first reported in the 1970s, but diseases in sea urchins had been little studied before the advent of aquaculture. In 1981, a bacterial diseases known as "spotting disease" caused almost complete mortality in juvenile Pseudocentrotus depressus and Hemicentrotus pulcherrimus, both cultivated in Japan, and recurred in succeeding years. It was divided into a cool-water "spring" disease and a hot-water "summer" form.[23] Another disease, known as bald sea urchin disease, causes loss of spines and skin lesions and is believed to be bacterial in origin.[24]
Adult sea urchins are usually well protected against most predators by their strong and sharp spines, which can be venomous in some species.[25] The small urchin clingfish lives among the spines of urchins such as Diadema; juveniles feed on the pedicellariae and sphaeridia, adult males choose the tube feet and adult females move away to feed on shrimp eggs and molluscs.[26]
Sea urchins are one of the favourite food of many lobsters, crabs, triggerfish, California sheephead, sea otter and wolf eels (which specialise in sea urchins): all these animals carry particular adaptations (teeth, pincers, claws) and a strength that allow them to overcome the excellent protective features of sea urchins. Left unchecked, urchins devastate their environments, creating what biologists call an urchin barren, devoid of macroalgae and associated fauna. Sea otters have re-entered British Columbia, dramatically improving coastal ecosystem health.[27]
Sea urchins are hosts to many parasites, be they internal or external.
Wolf eel, a highly specialized predator of sea urchins
A sea otter feeding on a purple sea urchin.
A crab (Carpilius convexus) attacking a slate pencil sea urchin (Heterocentrotus mamillatus)
A wrasse finishing the remains of a damaged Tripneustes gratilla
Anti-predator defences[edit]
The flower urchin is a dangerous, potentially lethally venomous species.
The spines, long and sharp in some species, protect the urchin from predators. Some tropical sea urchins like Diadematidae, Echinothuriidae and Toxopneustidae have venomous spines. Other creatures also make use of these defences; crabs, shrimps and other organisms shelter among the spines, and often adopt the colouring of their host. Some crabs in the Dorippidae family carry sea urchins, starfish, sharp shells or other protective objects in their claws.[28]
Pedicellaria[29] are a good means of defense against ectoparasites, but not a panacea as some of them actually feed on it.[30] The hemal system defends against endoparasites.[31]
Range and habitat[edit]
Sea urchins have conquered most sea habitats, on an extremely wide range of depths.[32] Some species, such as Cidaris abyssicola, can live down to several thousands of meters deep. Many genera are totally indentured to the abyssal zone, such as many cidaroids, most of the genera in the Echinothuriidae family, or the strange genus Dermechinus. One of the deepest-living family is the Pourtalesiidae,[33] strange bottle-shaped irregular sea urchins that live only in the hadal zone and have been collected as far as 6850 metres deep in the Java trench.[34] Nevertheless, this makes sea urchin the class of echinoderms living the least deep, compared to brittle stars, starfish and crinoids that remain abundant below 8,000 m (26,250 ft) and sea cucumbers which have been recorded from 10,687 m (35,100 ft).[34]
Population densities vary by habitat, with more dense populations in barren areas as compared to kelp stands.[35][36] Even in these barren areas, greatest densities are found in shallow water. Populations are generally found in deeper water if wave action is present.[36] Densities decrease in winter when storms cause them to seek protection in cracks and around larger underwater structures.[36] The shingle urchin (Colobocentrotus atratus), which lives on exposed shorelines, is particularly resistant to wave action. It is one of the few sea urchin that can survive many hours out of water.[37]
Sea urchins can be found in all climates, from warm seas to polar oceans.[32] The larvae of the polar sea urchin Sterechinus neumayeri have been found to use energy in metabolic processes twenty-five times more efficiently than do most other organisms.[38] Despite their presence in nearly all the marine ecosystems, most species are found on temperate and tropical coasts, between the surface and some tens of meters deep, close to photosynthetic food sources.[32]
Purple sea urchins at low tide in California. They dig a cavity in the rock to hide from predators during the day.
Dermechinus horridus, an abyssal species, at thousands of meters deep
Antarctic sea urchin (Sterechinus neumayeri) inhabits frozen seas.
The shape of the shingle urchin allows it to stay on wave-beaten cliffs.
Evolution[edit]
Fossil history[edit]
The thick spines (radiola) of Cidaridae were used for walking on the soft seabed.
The earliest echinoid fossils date to the upper part of the Ordovician period (circa 450 Mya).[39] There is a rich fossil record, their hard tests made of calcite plates surviving in rocks from every period since then.[40] Spines are present in some well-preserved specimens, but usually only the test remains. Isolated spines are common as fossils. Some Jurassic and Cretaceous Cidaroida had very heavy, club-shaped spines.[41]
Most fossil echinoids from the Paleozoic era are incomplete, consisting of isolated spines and small clusters of scattered plates from crushed individuals, mostly in Devonian and Carboniferous rocks. The shallow-water limestones from the Ordovician and Silurian periods of Estonia are famous for echinoids.[42] Paleozoic echinoids probably inhabited relatively quiet waters. Because of their thin tests, they would certainly not have survived in the wave-battered coastal waters inhabited by many modern echinoids.[42] Echinoids declined to near extinction at the end of the Paleozoic era, with just six species known from the Permian period. Only two lineages survived this period's massive extinction and into the Triassic: the genus Miocidaris, which gave rise to modern cidaroida (pencil urchins), and the ancestor that gave rise to the euechinoids. By the upper Triassic, their numbers increased again. Cidaroids have changed very little since the Late Triassic, and are the only Paleozoic echinoid group to have survived.[42]
The euechinoids diversified into new lineages in the Jurassic and Cretaceous periods, and from them emerged the first irregular echinoids (the Atelostomata) during the early Jurassic.[43]
Some echinoids, such as Micraster in the chalk of the Cretaceous period, serve as zone or index fossils. Because they are abundant and evolved rapidly, they enable geologists to date the surrounding rocks.[44]
In the Paleogene and Neogene periods (circa 66 to 1.8 Mya), sand dollars (Clypeasteroida) arose. Their distinctive, flattened tests and tiny spines were adapted to life on or under loose sand in shallow water, and they are abundant as fossils in southern European limestones and sandstones.[42]
Archaeocidaris brownwoodensis, Cidaroida, Carboniferous, c. 300 mya
Miocidaris coaeva, Cidaroida, Middle Triassic, c. 240 mya
Clypeus plotti, Irregularia, Middle Jurassic, c. 162 mya
Echinocorys, Holasteroida, Upper Cretaceous, c. 80 mya
Echinolampas ovalis, Cassiduloida, Middle Eocene, c. 40 mya
Clypeaster portentosus, Clypeasteroida, Miocene, c. 10 mya
Phylogeny[edit]
External[edit]
Echinoids are deuterostome animals, like the chordates. A 2014 analysis of 219 genes from all classes of echinoderms gives the following phylogenetic tree.[45] Approximate dates of branching of major clades are shown in millions of years ago (mya).
Bilateria
Xenacoelomorpha

Nephrozoa
Deuterostomia
Chordata and allies

Echinodermata

Echinozoa
Holothuroidea
Sea cucumbers
Echinoidea
c. 450 mya

Asterozoa
Ophiuroidea
Brittle stars
Asteroidea
Starfish

Crinoidea
Crinoids
c. 500 mya
>540 mya
Protostomia

Ecdysozoa

Spiralia

610 mya
650 mya

Internal[edit]
The phylogeny of the sea urchins is as follows:[46][47]
Echinoidea

Cidaroida

Euechinoidea

Echinothurioida

Acroechinoidea

Diadematoida

Irregularia

Pedinoida

Salenioida

Echinacea

Stomopneustidae

Arbaciidae

Camarodonta

Parasaleniidae

Temnopleuridae

Trigonocidaridae

Echinoida

Echinidae

Parechinidae

Toxopneustidae

Echinometridae

Strongylocentrotidae

450 mya
Relation to humans[edit]
Injuries[edit]
Sea urchin injury on the top side of the foot. This injury resulted in some skin staining from the natural purple-black dye of the urchin.
Sea urchin injuries are puncture wounds inflicted by the animal's brittle, fragile spines.[48] These are a common source of injury to ocean swimmers, especially along coastal surfaces where coral with stationary sea urchins are present. Their stings vary in severity depending on the species. Their spines can be venomous or cause infection. Granuloma and staining of the skin from the natural dye inside the sea urchin can also occur. Breathing problems may indicate a serious reaction to toxins in the sea urchin.[49] They inflict a painful wound when they penetrate human skin, but are not themselves dangerous if fully removed promptly; if left in the skin, further problems may occur.[50]
Science[edit]
Sea urchins are traditional model organisms in developmental biology. This use originated in the 1800s, when their embryonic development became easily viewed by microscopy. The transparency of the urchin's eggs enabled them to be used to observe that sperm cells actually fertilize ova.[51] They continue to be used for embryonic studies, as prenatal development continues to seek testing for fatal diseases. Sea urchins are being used in longevity studies for comparison between the young and old of the species, particularly for their ability to regenerate tissue as needed.[52] Scientists at the University of St Andrews have discovered a genetic sequence, the '2A' region, in sea urchins previously thought to have belonged only to viruses that afflict humans like foot-and-mouth disease virus.[53] More recently, Eric H. Davidson and Roy John Britten argued for the use of urchins as a model organism due to their easy availability, high fecundity, and long lifespan. Beyond embryology, urchins provide an opportunity to research cis-regulatory elements.[54] Oceanography has taken in interest in monitoring the health of urchins and their populations as a way to assess overall ocean acidification,[55] temperatures, and ecological impacts.
The organism's evolutionary placement and unique embryology with five-fold symmetry were the major arguments in the proposal to seek the sequencing of its genome. Importantly, urchins act as the closest living relative to chordates and thus are of interest for the light they can shed on the evolution of vertebrates.[56] The genome of Strongylocentrotus purpuratus, was completed in 2006 and established homology between sea urchin and vertebrate immune system-related genes. Sea urchins code for at least 222 Toll-like receptor genes and over 200 genes related to the Nod-like-receptor family found in vertebrates.[57] This increases its usefulness as a valuable model organism for studying the evolution of innate immunity. The sequencing also revealed that while some genes were thought to be limited to vertebrates, there were also innovations that have previously never been seen outside the chordate classification, such as immune transcription factors PU.1 and SPIB.[56]
As food[edit]
The gonads of both male and female sea urchins, usually called sea urchin roe or corals,[58] are culinary delicacies in many parts of the world.[59][60][61] In Mediterranean cuisines, Paracentrotus lividus is often eaten raw, or with lemon,[62] and known as ricci on Italian menus where it is sometimes used in pasta sauces. It can also flavour omelettes, scrambled eggs, fish soup,[63] mayonnaise, béchamel sauce for tartlets,[64] the boullie for a soufflé,[65] or Hollandaise sauce to make a fish sauce.[66] In Chilean cuisine, it is served raw with lemon, onions, and olive oil. Though the edible Strongylocentrotus droebachiensis is found in the North Atlantic, it is not widely eaten. However, sea urchins (called uutuk in Alutiiq) are commonly eaten by the Alaska Native population around Kodiak Island. It is commonly exported, mostly to Japan.[67] In the West Indies, slate pencil urchins are eaten.[59] On the Pacific Coast of North America, Strongylocentrotus franciscanus was praised by Euell Gibbons; Strongylocentrotus purpuratus is also eaten.[59] In New Zealand, Evechinus chloroticus, known as kina in Maori, is a delicacy, traditionally eaten raw. Though New Zealand fishermen would like to export them to Japan, their quality is too variable.[68] In Japan, sea urchin is known as uni (うに), and its roe can retail for as much as ¥40000 ($360) per kg;[69] it is served raw as sashimi or in sushi, with soy sauce and wasabi. Japan imports large quantities from the United States, South Korea, and other producers. Japanese demand for sea urchin corals has raised concerns about overfishing.[70] Native Americans in California are also known to eat sea urchins.[71] The coast of Southern California is known as a source of high quality uni, with divers picking sea urchin from kelp beds in depths as low as 24 m/80 ft.[72] As of 2013, the state was limiting the practice to 300 sea urchin diver licenses.[72]
Sea urchin (uni) as sashimi with a dab of wasabi
Japanese uni-ikura don, sea urchin egg and salmon egg donburi
Open sea urchins in Sicily
Aquaria[edit]
A fossil sea urchin found on a Middle Saxon site in Lincolnshire, thought to have been used as an amulet[73]
Some species of sea urchins, such as the slate pencil urchin (Eucidaris tribuloides), are commonly sold in aquarium stores. Some species are effective at controlling hair algae, and they make good additions to an invertebrate tank.[74]
Folklore[edit]
A folk tradition in Denmark and southern England imagined sea urchin fossils to be thunderbolts, able to ward off harm by lightning or by witchcraft, as an apotropaic symbol.[75] Another version supposed they were petrified eggs of snakes, able to protect against heart and liver disease, poisons, and injury in battle, and accordingly they were carried as amulets. These were, according to the legend, created by magic from foam made by the snakes at midsummer.[76]
See also[edit]
Sea urchin injury
Notes[edit]
Jump up ^ The tube feet are present in all parts of the animal except around the anus, so technically, the whole surface of the body should be considered to be the oral surface, with the aboral (non-mouth) surface limited to the immediate vicinity of the anus.[9]
References[edit]
Jump up ^ "Animal Diversity Web – Echinoidea". University of Michigan Museum of Zoology. Retrieved 26 August 2012.
Jump up ^ Wright, Anne. 1851. The Observing Eye, Or, Letters to Children on the Three Lowest Divisions of Animal Life. London: Jarrold and Sons, p. 107.
Jump up ^ Soyer, Alexis. 1853. The Pantropheon Or History Of Food, And Its Preparation: From The Earliest Ages Of The World. Boston: Ticknor, Reed, and Fields,, p. 245.
Jump up ^ "urchin (n.)". Online Etymology Dictionary. Retrieved 13 March 2018.
Jump up ^ Kroh, A.; Hansson, H. (2013). "Echinoidea (Leske, 1778)". World Register of Marine Species. Retrieved 2014-01-04. CS1 maint: Multiple names: authors list (link)
^ Jump up to: a b c d e f g h i j k l m Barnes, Robert D. (1982). Invertebrate Zoology. Philadelphia, PA: Holt-Saunders International. pp. 961–981. ISBN 0-03-056747-5.
Jump up ^ Guill, Michael. "Taxonomic Etymologies EEOB 111". Retrieved 13 March 2018.
Jump up ^ Stachan and Read, Human Molecular Genetics, p. 381: "What Makes Us Human"
^ Jump up to: a b c d e f g h i j k l m Ruppert, Edward E.; Fox, Richard, S.; Barnes, Robert D. (2004). Invertebrate Zoology, 7th edition. Cengage Learning. pp. 896–906. ISBN 978-81-315-0104-7.
Jump up ^ "Sea urchins reveal promising carbon capture alternative". Gizmag. 4 February 2013. Retrieved 2013-02-05.
Jump up ^ Kazuya Yoshimura, Tomoaki Iketani et Tatsuo Motokawa, "Do regular sea urchins show preference in which part of the body they orient forward in their walk ?", Marine Biology, vol. 159, no 5, 2012, p. 959–965.
Jump up ^ Boudouresque, Charles F.; Verlaque, Marc (2006). "13: Ecology of Paracentrotus lividus". In Lawrence, John, M. Edible Sea Urchins: Biology and Ecology. Elsevier. p. 243. ISBN 978-0-08-046558-6.
Jump up ^ Claw inspired by sea urchins' mouth can scoop up Martian soil
Jump up ^ Voultsiadou, Eleni; Chintiroglou, Chariton (2008). "Aristotle's lantern in echinoderms: an ancient riddle". Cahiers de Biologie Marine. Station Biologique de Roscoff. 49 (3): 299–302.
Jump up ^ Choi, Charles Q. (29 December 2010). "Rock-Chewing Sea Urchins Have Self-Sharpening Teeth". National Geographic News. Retrieved 2017-11-12.
Jump up ^ Knight, K. (2009). "Sea Urchins Use Whole Body As Eye". Journal of Experimental Biology. 213 (2): i. doi:10.1242/jeb.041715. Lay summary – LiveScience (December 28, 2009).
Jump up ^ A. Gaion, A. Scuderi; D. Pellegrini; D. Sartori (2013). "Arsenic Exposure Affects Embryo Development of Sea Urchin, Paracentrotus lividus (Lamarck, 1816)". Bulletin of Environmental Contamination and Toxicology: 1–5. doi:10.3109/01480545.2015.1041602.
Jump up ^ Kominami, Tetsuya; Takata, Hiromi (2004). "Gastrulation in the sea urchin embryo: a model system for analyzing the morphogenesis of a monolayered epithelium". Development, Growth & Differentiation. 46 (4): 309–26. doi:10.1111/j.1440-169x.2004.00755.x.
Jump up ^ Shook, D; Keller, R (2003). "Mechanisms, mechanics and function of epithelial-mesenchymal transitions in early development". Mechanisms of development. 120 (11): 1351–83. doi:10.1016/j.mod.2003.06.005. PMID 14623443. ; Katow, Hideki; Solursh, Michael (1980). "Ultrastructure of primary mesenchyme cell ingression in the sea urchinLytechinus pictus". Journal of Experimental Zoology. 213 (2): 231–246. doi:10.1002/jez.1402130211. ; Balinsky, BI (1959). "An electro microscopic investigation of the mechanisms of adhesion of the cells in a sea urchin blastula and gastrula". Experimental Cell Research. 16 (2): 429–33. doi:10.1016/0014-4827(59)90275-7. PMID 13653007. ; Hertzler, PL; McClay, DR (1999). "alphaSU2, an epithelial integrin that binds laminin in the sea urchin embryo". Developmental Biology. 207 (1): 1–13. doi:10.1006/dbio.1998.9165. PMID 10049560. ; Fink, RD; McClay, DR (1985). "Three cell recognition changes accompany the ingression of sea urchin primary mesenchyme cells". Developmental Biology. 107 (1): 66–74. doi:10.1016/0012-1606(85)90376-8. PMID 2578117. ; Burdsal, CA; Alliegro, MC; McClay, DR (1991). "Tissue-specific, temporal changes in cell adhesion to echinonectin in the sea urchin embryo". Developmental Biology. 144 (2): 327–34. doi:10.1016/0012-1606(91)90425-3. PMID 1707016. ; Miller, JR; McClay, DR (1997). "Characterization of the Role of Cadherin in Regulating Cell Adhesion during Sea Urchin Development". Developmental Biology. 192 (2): 323–39. doi:10.1006/dbio.1997.8740. PMID 9441671. ; Miller, JR; McClay, DR (1997). "Changes in the pattern of adherens junction-associated beta-catenin accompany morphogenesis in the sea urchin embryo". Developmental Biology. 192 (2): 310–22. doi:10.1006/dbio.1997.8739. PMID 9441670. ; Anstrom, JA (1989). "Sea urchin primary mesenchyme cells: ingression occurs independent of microtubules". Developmental Biology. 131 (1): 269–75. doi:10.1016/S0012-1606(89)80058-2. PMID 2562830. ; Anstrom, JA (1992). "Microfilaments, cell shape changes, and the formation of primary mesenchyme in sea urchin embryos". The Journal of Experimental Zoology. 264 (3): 312–22. doi:10.1002/jez.1402640310. PMID 1358997.
Jump up ^ Warner, Jacob F.; Lyons, Deirdre C.; McClay, David R. (2012). "Left-Right Asymmetry in the Sea Urchin Embryo: BMP and the Asymmetrical Origins of the Adult". PLoS Biology. 10 (10): e1001404. doi:10.1371/journal.pbio.1001404.
Jump up ^ Worley, Alisa (2001). "Strongylocentrotus purpuratus". Animal Diversity Web. Retrieved 2016-12-05.
Jump up ^ Baumiller, Tomasz K. (2008). "Crinoid Ecological Morphology". Annual Review of Earth and Planetary Sciences. 36: 221–49. Bibcode:2008AREPS..36..221B. doi:10.1146/annurev.earth.36.031207.124116.
Jump up ^ Lawrence, John M. (2006). Edible Sea Urchins: Biology and Ecology. Elsevier. pp. 167–168. ISBN 978-0-08-046558-6.
Jump up ^ Michel Jangoux (1987). "Diseases of Echinodermata. I. Agents microorganisms and protistans" (PDF). Diseases of Aquatic Organisms. 2: 147–162. doi:10.3354/dao002147.
Jump up ^ "Defence – spines". Echinoid Directory. Natural History Museum.
Jump up ^ Sakashita, Hiroko (1992). "Sexual dimorphism and food habits of the clingfish, Diademichthys lineatus, and its dependence on host sea urchin". Environmental Biology of Fishes. 34 (1): 95–101. doi:10.1007/BF00004787.
Jump up ^ "Aquatic Species at Risk – Species Profile – Sea Otter". Fisheries and Oceans Canada. Archived from the original on 2008-01-23. Retrieved 2007-11-29.
Jump up ^ Thiel, Martin; Watling, Les (2015). Lifestyles and Feeding Biology. Oxford University Press. pp. 200–202. ISBN 978-0-19-979702-8.
Jump up ^ "Defence – pedicellariae". Echinoid Directory. Natural History Museum.
Jump up ^ Hiroko Sakashita, " Sexual dimorphism and food habits of the clingfish, Diademichthys lineatus, and its dependence on host sea urchin ", Environmental Biology of Fishes, vol. 34, no 1, 1994, p. 95–101
Jump up ^ Jangoux, M. (1984). "Diseases of echinoderms" (PDF). Retrieved 23 March 2018.
^ Jump up to: a b c Kroh, Andreas (2010). "The phylogeny and classification of post-Palaeozoic echinoids". Journal of Systematic Palaeontology. 8 (2): 147–212. doi:10.1080/14772011003603556. .
Jump up ^ Mah, Christopher (April 12, 2011). "Sizes and Species in the Strangest of the Strange : Deep-Sea Pourtalesiid Urchins". The Echinoblog. .
^ Jump up to: a b Mah, Christopher (8 April 2014). "What are the Deepest known echinoderms?". The Echinoblog. Retrieved 22 March 2018. .
Jump up ^ Mattison, J.E.; Trent, J.D.; Shanks, AL; Akin, T.B.; Pearse, J.S. (1977). "Movement and feeding activity of red sea urchins (Strongylocentrotus franciscanus) adjacent to a kelp forest". Marine Biology. 39 (1): 25–30. doi:10.1007/BF00395589.
^ Jump up to: a b c Konar, Brenda (2000). "Habitat influences on sea urchin populations". In: Hallock and French (eds). Diving for Science...2000. Proceedings of the 20th Annual Scientific Diving Symposium. American Academy of Underwater Sciences. Retrieved 7 January 2011.
Jump up ^ ChrisM. "The Echinoblog". echinoblog.blogspot.com.
Jump up ^ Antarctic Sea Urchin Shows Amazing Energy-Efficiency in Nature's Deep Freeze 15 March 2001 University Of Delaware. Retrieved 22 March 2018
Jump up ^ "Echinoids". British Geological Survey. 2017. Retrieved 14 March 2018.
Jump up ^ "The Echinoid Directory". Natural History Museum. Retrieved 16 March 2018.
Jump up ^ "The Echinoid Directory". Natural History Museum. Retrieved 16 March 2018.
^ Jump up to: a b c d Kirkaldy, J. F. (1967). Fossils in Colour. London: Blandford Press. pp. 161–163.
Jump up ^ Schultz, Heinke A.G. (2015). Echinoidea: with pentameral symmetry. Walter de Gruyter. pp. 36 ff, section 2.4. ISBN 978-3-11-038601-1.
Jump up ^ Wells, H. G.; Huxley, Julian; Wells, G. P. (1931). The Science of life. pp. 346–348.
Jump up ^ Telford, M. J.; Lowe, C. J.; Cameron, C. B.; Ortega-Martinez, O.; Aronowicz, J.; Oliveri, P.; Copley, R. R. (2014). "Phylogenomic analysis of echinoderm class relationships supports Asterozoa". Proceedings of the Royal Society B: Biological Sciences. 281 (1786): 20140479–20140479. doi:10.1098/rspb.2014.0479.
Jump up ^ Planet, Paul J.; Ziegler, Alexander; Schröder, Leif; Ogurreck, Malte; Faber, Cornelius; Stach, Thomas (2012). "Evolution of a Novel Muscle Design in Sea Urchins (Echinodermata: Echinoidea)". PLoS ONE. 7 (5): e37520. doi:10.1371/journal.pone.0037520.
Jump up ^ Kroh, Andreas; Smith, Andrew B. (2010). "The phylogeny and classification of post-Palaeozoic echinoids". Journal of Systematic Palaeontology. 8 (2): 147–212. doi:10.1080/14772011003603556.
Jump up ^ James, William D.; Berger, Timothy G.; et al. (2006). Andrews' Diseases of the Skin: clinical Dermatology. Saunders Elsevier. p. 431. ISBN 0-7216-2921-0.
Jump up ^ Gallagher, Scott A. "Echinoderm Envenomation". eMedicine. Retrieved 12 October 2010.
Jump up ^ Matthew D. Gargus; David K. Morohashi (2012). "A sea-urchin spine chilling remedy" (letter to the Editor). New England Journal of Medicine. 30 (19): 1867–1868. doi:10.1056/NEJMc1209382.
Jump up ^ "Insight from the Sea Urchin". Microscope Imaging Station. Exploratorium. Archived from the original on 2013-12-01. Retrieved 2018-03-07.
Jump up ^ Bodnar, Andrea G.; Coffman, James A. (2016-08-01). "Maintenance of somatic tissue regeneration with age in short- and long-lived species of sea urchins". Aging Cell. 15 (4): 778–787. doi:10.1111/acel.12487. ISSN 1474-9726. PMC 4933669  . PMID 27095483.
Jump up ^ Roulston, C.; Luke, G.A.; de Felipe, P.; Ruan, L.; Cope, J.; Nicholson, J.; Sukhodub, A.; Tilsner, J.; Ryan, M.D. (2016). "'2A‐Like' Signal Sequences Mediating Translational Recoding: A Novel Form of Dual Protein Targeting". Traffic. 17: 923–39. doi:10.1111/tra.12411. PMC 4981915  . PMID 27161495.
Jump up ^ "Sea Urchin Genome Project". sugp.caltech.edu. Retrieved 2016-12-05.
Jump up ^ "Stanford seeks sea urchin's secret to surviving ocean acidification | Stanford News Release". news.stanford.edu. Retrieved 2016-12-05.
^ Jump up to: a b Sodergren, E; Weinstock, GM; Davidson, EH; et al. (2006-11-10). "The Genome of the Sea Urchin Strongylocentrotus purpuratus". Science. 314 (5801): 941–952. doi:10.1126/science.1133609. PMC 3159423  . PMID 17095691. CS1 maint: Explicit use of et al. (link)
Jump up ^ Rast, JP; Smith, LC; Loza-Coll, M; Hibino, T; Litman, GW (2006). "Genomic Insights into the Immune System of the Sea Urchin". Science. 314 (5801): 952–6. Bibcode:2006Sci...314..952R. doi:10.1126/science.1134301. PMID 17095692.
Jump up ^ Laura Rogers-Bennett, "The Ecology of Strongylocentrotus franciscanus and Strongylocentrotus purpuratus" in John M. Lawrence, Edible sea urchins: biology and ecology, p. 410
^ Jump up to: a b c Davidson, Alan (2014) Oxford Companion to Food. Oxford University Press, 3rd edition. pp. 730–731.
Jump up ^ John M. Lawrence, "Sea Urchin Roe Cuisine" in John M. Lawrence, Edible sea urchins: biology and ecology
Jump up ^ "The Rise of the Sea Urchin", Franz Lidz July 2014 - Smithsonian
Jump up ^ for Puglia, Italy: Touring Club Italiano, Guida all'Italia gastronomica, 1984, p. 314; for Alexandria, Egypt: Claudia Roden, A Book of Middle Eastern Food, p. 183
Jump up ^ Alan Davidson, Mediterranean Seafood, p. 270
Jump up ^ Larousse Gastronomique[page needed]
Jump up ^ Curnonsky, Cuisine et vins de France, nouvelle édition, 1974, p. 248
Jump up ^ Davidson, Alan (2014) Oxford Companion to Food. Oxford University Press, 3rd edition. p. 280
Jump up ^ Kleiman, Dena (October 3, 1990). "Scorned at Home, Maine Sea Urchin Is a Star in Japan". New York Times. p. C1.
Jump up ^ Wassilieff, Maggy (March 2, 2009). "sea urchins". Te Ara: The Encyclopedia of New Zealand.
Jump up ^ Macey, Richard (November 9, 2004). "The little urchins that can command a princely price". The Sydney Morning Herald.
Jump up ^ "Sea Urchin Fishery and Overfishing", TED Case Studies 296, American University full text
Jump up ^ Martin, R.E.; Carter, E.P.; Flick, G.J.; Davis, L.M. (2000). Marine and Freshwater Products Handbook. Taylor & Francis. p. 268. ISBN 978-1-56676-889-4. Retrieved 2014-12-03.
^ Jump up to: a b Lam, Francis (2014-03-14). "California Sea Urchin Divers, Interviewed by Francis Lam". Bon Appetit. Retrieved 2017-03-26.
Jump up ^ "Amulet | LIN-B37563". Portable Antiquities Scheme. Retrieved 14 March 2018.
Jump up ^ Tullock, John H. (2008). Your First Marine Aquarium: Everything about Setting Up a Marine Aquarium, Including Conditioning, Maintenance, Selecting Fish and Invertebrates, and More. Barron's Educational Series. p. 1. ISBN 978-0-7641-3675-7.
Jump up ^ McNamara, Ken (2012). "Prehistoric fossil collectors". The Geological Society. Retrieved 14 March 2018.
Jump up ^ Marren, Peter; Mabey, Richard (2010). Bugs Britannica. Chatto & Windus. pp. 469–470. ISBN 978-0-7011-8180-2.
External links[edit]
Wikimedia Commons has media related to Sea urchin.
World Register of Marine Species link: Echinoidea Leske, 1778 (+species list)
The sea urchin genome project
Sea Urchin Harvesters Association – California Also, (604) 524-0322.
The Echinoid Directory from the Natural History Museum.
Virtual Urchin at Stanford
California Sea Urchin commission
Introduction to the Echinoidea at UCMP Berkeley
[hide]
v
t
e
Principal commercial fishery species groups
Wild
Large pelagic fish
Mackerel
Salmon
Saury
Shark
Swordfish
Tuna
albacore
bigeye
Atlantic bluefin
Pacific bluefin
southern bluefin
skipjack
yellowfin
Forage fish
Anchovy
Capelin
Herring
Ilish
Menhaden
Sardines
Shad
Sprat
european
Demersal fish
Catfish
Cod
Atlantic
Pacific
Alaska pollock
Flatfish
flounder
halibut
plaice
sole
turbot
Haddock
Mullet
Orange roughy
Pollock
Rockfish
Smelt-whitings
Toothfish
Freshwater fish
Carp
Sturgeon
Tilapia
Trout
Other wild fish
Eel
Whitebait
more...
Crustaceans
Crab
Krill
Lobster
Shrimp
more...
Molluscs
Abalone
Mussels
Octopus
Oysters
Scallops
Squid
more...
Echinoderms
Sea cucumbers
Sea urchin
more...

Farmed
Carp
bighead
common
crucian
grass
silver
Catfish
Freshwater prawns
Gilt-head bream
Mussels
Oysters
Salmon
Atlantic
salmon trout
coho
chinook
Scallops
Seaweed
Shrimp
Tilapia
Commercial fishing
World fish production
Commercial species
Fishing topics
Fisheries glossary
Marine life portal
Animals portal
Biology portal
Taxon identifiers
Wd: Q83483
ADW: Echinoidea
EoL: 1971
Fossilworks: 32733
GBIF: 221
ITIS: 157821
NCBI: 7625
WoRMS: 123082
Authority control
GND: 4054135-6
NDL: 00574014
Retrieved from "https://en.wikipedia.org/w/index.php?title=Sea_urchin&oldid=835290689"
Categories:
Commercial echinoderms
Echinoidea
Edible shellfish
Japanese seafood
Seafood in Native American cuisine
Animal models
Animal developmental biology
Negligibly senescent organisms
Late Ordovician first appearances
Extant Ordovician first appearances
Korean seafood
Hidden categories:
CS1 maint: Multiple names: authors list
CS1 maint: Explicit use of et al.
Wikipedia articles needing page number citations from November 2010
Articles with 'species' microformats
Articles containing Japanese-language text
Commons category with local link different than on Wikidata
Wikipedia articles with GND identifiers
Articles containing video clips
Navigation menu
Personal tools
Not logged in
Talk
Contributions
Create account
Log in
Namespaces
Article
Talk
Variants
Views
Read
Edit
View history
More
Search
Navigation
Main page
Contents
Featured content
Current events
Random article
Donate to Wikipedia
Wikipedia store
Interaction
Help
About Wikipedia
Community portal
Recent changes
Contact page
Tools
What links here
Related changes
Upload file
Special pages
Permanent link
Page information
Wikidata item
Cite this page
Print/export
Create a book
Download as PDF
Printable version
In other projects
Wikimedia Commons
Wikispecies
Languages
Afrikaans
العربية
Asturianu
Azərbaycanca
تۆرکجه
Беларуская
Беларуская (тарашкевіца)
Български
Bosanski
Brezhoneg
Català
Cebuano
Čeština
Dansk
Deutsch
Diné bizaad
Eesti
Ελληνικά
Эрзянь
Español
Esperanto
Euskara
فارسی
Français
Gaeilge
Galego
한국어
Հայերեն
हिन्दी
Hrvatski
Ido
Bahasa Indonesia
Interlingua
Íslenska
Italiano
עברית
ქართული
Қазақша
Кыргызча
Кырык мары
Latina
Latviešu
Lietuvių
Magyar
Македонски
മലയാളം
Nederlands
日本語
Norsk
Norsk nynorsk
Occitan
Oʻzbekcha/ўзбекча
Polski
Português
Română
Runa Simi
Русский
Scots
Sicilianu
Simple English
Slovenčina
Slovenščina
Српски / srpski
Srpskohrvatski / српскохрватски
Suomi
Svenska
Tagalog
தமிழ்
ไทย
Türkçe
Українська
Tiếng Việt
Winaray
粵語
中文
66 more
Edit links
This page was last edited on 7 April 2018, at 19:34.
Text is available under the Creative Commons Attribution-ShareAlike License; additional terms may apply. By using this site, you agree to the Terms of Use and Privacy Policy. Wikipedia® is a registered trademark of the Wikimedia Foundation, Inc., a non-profit organization.
Privacy policy
About Wikipedia
Disclaimers
Contact Wikipedia
Developers
Cookie statement
Mobile view
Enable previews

values: mw-page-base noprint

values: mw-head-base noprint

values: firstHeading firstHeading en

values: siteSub noprint

values: jump-to-nav mw-jump

attrs: href class title

values:
/wiki/Sea_urchin_(disambiguation)
mw-disambig
Sea urchin (disambiguation)

attrs: role class

values:
note
hatnote navigation-not-searchable

values: position:absolute; height:100%; text-align:center; background-color:rgb(129,170,114); left:36.892307692308px; width:18.818461538462px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(0,169,138); left:55.710769230769px; width:14.08px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(166,223,197); left:69.790769230769px; width:8.3261538461539px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(221,150,81); left:78.116923076923px; width:20.409230769231px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(63,174,173); left:98.526153846154px; width:20.307692307692px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(247,88,60); left:118.83384615385px; width:15.907015384615px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(153,78,150); left:134.74086153846px; width:17.126830769231px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(0,187,231); left:151.86769230769px; width:19.055384615385px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(111,200,107); left:170.92307692308px; width:26.738461538462px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(254,161,99); left:197.66153846154px; width:14.543692307692px;

values: position:absolute; height:100%; text-align:center; background-color:rgb(254,221,45); left:212.20523076923px; width:6.9215384615385px;

values: position:absolute; height:100%; background-color:#666; width:1px; left:219px

values: position:absolute; height:8px; left:55.710769230769px; width:164.28923076923px; background-color:#360; opacity:0.42;

values: position:absolute; height:8px; left:55.710769230769px; width:164.28923076923px; background-color:#360; opacity:1;

values: position:absolute; height:6px; top:1px; left:56.710769230769px; width:162.28923076923px; background-color:#6c3;

values: margin:0 auto; line-height:0; clear:both; width:220px; padding:0px; height:8px; overflow:visible; background-color:transparent; position:relative; top:-4px; z-index:100;

values: margin: 4px auto 0; clear:both; width:220px; padding:0px; height:18px; overflow:visible; border:1px #666; border-style:solid none; position:relative; z-index:0; font-size:13px;

values: text-align: center; background-color: rgb(235,235,210)

values: Tripneustes ventricosus (West Indian Sea Egg-top) and Echinometra viridis (Reef Urchin - bottom).jpg

attrs: alt src width height data-file-width data-file-height

values: font-size:smaller; float:right; padding-right:0.4em; margin-left:-3em;

values: min-width:15em; text-align: center; background-color: rgb(235,235,210)

values:
/wiki/Nathaniel_Gottfried_Leske
mw-redirect
Nathaniel Gottfried Leske

values: text-align: left; width: 200px; font-size: 100%

values:
/wiki/Bilateral_symmetry
mw-redirect
Bilateral symmetry

values:
/wiki/Model_organisms
mw-redirect
Model organisms

values:
/wiki/List_of_echinodermata_orders
mw-redirect
List of echinodermata orders

values:
/wiki/Symmetry_(biology)#Pentamerism
mw-redirect
Symmetry (biology)

values:
/wiki/Sessility_(zoology)
mw-redirect
Sessility (zoology)

values:
/wiki/Hydraulic_pressure
mw-redirect
Hydraulic pressure

values: Echinodiscus tenuissimus (page does not exist)

values:
/wiki/D%27Arcy_Thompson
mw-redirect
D'Arcy Thompson

values:
/wiki/Heart_urchin
mw-redirect
Heart urchin

values: Edit section: Circulation and respiration

values:
/wiki/Blood_clotting
mw-redirect
Blood clotting

values: File:Male Flower Sea Urchin (toxopneustes roseus).theora.ogv

values: <video id="mwe_player_1" poster="//upload.wikimedia.org/wikipedia/commons/thumb/8/84/Male_Flower_Sea_Urchin_%28toxopneustes_roseus%29.theora.ogv/320px--Male_Flower_Sea_Urchin_%28toxopneustes_roseus%29.theora.ogv.jpg" controls="" preload="none" autoplay="" style="width:320px;height:240px" class="kskin" data-durationhint="19.066666666667" data-startoffset="0" data-mwtitle="Male_Flower_Sea_Urchin_(toxopneustes_roseus).theora.ogv" data-mwprovider="wikimediacommons"><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/8/84/Male_Flower_Sea_Urchin_%28toxopneustes_roseus%29.theora.ogv/Male_Flower_Sea_Urchin_%28toxopneustes_roseus%29.theora.ogv.240p.webm" type="video/webm; codecs="vp8, vorbis"" data-title="Small WebM (240P)" data-shorttitle="WebM 240P" data-transcodekey="240p.webm" data-width="320" data-height="240" data-bandwidth="253992" data-framerate="15"/><source src="//upload.wikimedia.org/wikipedia/commons/8/84/Male_Flower_Sea_Urchin_%28toxopneustes_roseus%29.theora.ogv" type="video/ogg; codecs="theora"" data-title="Original Ogg file, 320 × 240 (1.74 Mbps)" data-shorttitle="Ogg source" data-width="320" data-height="240" data-bandwidth="1735312" data-framerate="15"/><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/8/84/Male_Flower_Sea_Urchin_%28toxopneustes_roseus%29.theora.ogv/Male_Flower_Sea_Urchin_%28toxopneustes_roseus%29.theora.ogv.160p.webm" type="video/webm; codecs="vp8, vorbis"" data-title="Low bandwidth WebM (160P)" data-shorttitle="WebM 160P" data-transcodekey="160p.webm" data-width="214" data-height="160" data-bandwidth="128000" data-framerate="15"/></video>

values:
/wiki/Cell_Division
mw-redirect
Cell Division

values:
/wiki/Epithelial-mesenchymal_transition
mw-redirect
Epithelial-mesenchymal transition

values: Edit section: Life cycle and development

values: <video id="mwe_player_3" poster="//upload.wikimedia.org/wikipedia/commons/thumb/b/bf/Sea_Urchin.theora.ogv/320px--Sea_Urchin.theora.ogv.jpg" controls="" preload="none" autoplay="" style="width:320px;height:240px" class="kskin" data-durationhint="5.9333333333333" data-startoffset="0" data-mwtitle="Sea_Urchin.theora.ogv" data-mwprovider="wikimediacommons"><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/b/bf/Sea_Urchin.theora.ogv/Sea_Urchin.theora.ogv.240p.webm" type="video/webm; codecs="vp8, vorbis"" data-title="Small WebM (240P)" data-shorttitle="WebM 240P" data-transcodekey="240p.webm" data-width="320" data-height="240" data-bandwidth="262632" data-framerate="15"/><source src="//upload.wikimedia.org/wikipedia/commons/b/bf/Sea_Urchin.theora.ogv" type="video/ogg; codecs="theora"" data-title="Original Ogg file, 320 × 240 (1.86 Mbps)" data-shorttitle="Ogg source" data-width="320" data-height="240" data-bandwidth="1863719" data-framerate="15"/><source src="//upload.wikimedia.org/wikipedia/commons/transcoded/b/bf/Sea_Urchin.theora.ogv/Sea_Urchin.theora.ogv.160p.webm" type="video/webm; codecs="vp8, vorbis"" data-title="Low bandwidth WebM (160P)" data-shorttitle="WebM 160P" data-transcodekey="160p.webm" data-width="214" data-height="160" data-bandwidth="130592" data-framerate="15"/></video>

values: Edit section: Predators, parasites, and diseases

values:
/wiki/Hemicentrotus_pulcherrimus
mw-redirect
Hemicentrotus pulcherrimus

values:
/wiki/Anarrhichthys_ocellatus
mw-redirect
Anarrhichthys ocellatus

values:
/wiki/Thalassoma_duperrey
mw-redirect
Thalassoma duperrey

values:
/wiki/Tripneustes_gratilla
mw-redirect
Tripneustes gratilla

values:
/wiki/Flower_urchin
mw-redirect
Flower urchin

values:
/wiki/Shingle_urchin
mw-redirect
Shingle urchin

values:
/wiki/Dermechinus_horridus
mw-redirect
Dermechinus horridus

values:
/wiki/Million_years_ago
mw-redirect
Million years ago

values:
/wiki/Index_fossil
mw-redirect
Index fossil

values: border:0;padding:0 0.2em;border-left:1px solid;border-bottom:1px solid;vertical-align:bottom;text-align:center;

values: Crinoid on the reef of Batu Moncho Island (cropped).JPG

values: Fish4570 - Flickr - NOAA Photo Library.jpg

values: Toxic Leather Sea Urchin - Asthenosoma marisrubri.jpg

values: Diadema antillarum Flower Garden Banks.jpg

values: Clypeaster rosaceus (San Salvador Island, Bahamas) 3.jpg

values: Riccio Melone a Capo Caccia adventurediving.it.jpg

values: Heterocentrotus mammillatus in situ from Hawaii.JPG

values: Strongylocentrotus franciscanus at Telegraph Cove.jpg

values:
/wiki/Innate_immunity
mw-redirect
Innate immunity

values:
/wiki/Slate_pencil_urchin_(Atlantic)
mw-redirect
Slate pencil urchin (Atlantic)

values:
/wiki/Strongylocentrotus_franciscanus
mw-redirect
Strongylocentrotus franciscanus

values:
/wiki/Evechinus_chloroticus
mw-redirect
Evechinus chloroticus

values:
/wiki/Maori_language
mw-redirect
Maori language

values:
reflist mw-references-wrap
list-style-type: lower-alpha;

values:
nofollow
external text
https://www.etymonline.com/word/urchin

values: Category:CS1 maint: Multiple names: authors list

values:
nofollow
external text
//doi.org/10.1242%2Fjeb.041715

values:
nofollow
external text
//doi.org/10.1016%2Fj.mod.2003.06.005

values:
/wiki/PubMed_Identifier
mw-redirect
PubMed Identifier

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/14623443

values:
nofollow
external text
//doi.org/10.1002%2Fjez.1402130211

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/13653007

values:
nofollow
external text
//doi.org/10.1006%2Fdbio.1998.9165

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/10049560

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/2578117

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/1707016

values:
nofollow
external text
//doi.org/10.1006%2Fdbio.1997.8740

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/9441671

values:
nofollow
external text
//doi.org/10.1006%2Fdbio.1997.8739

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/9441670

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/2562830

values:
nofollow
external text
//doi.org/10.1002%2Fjez.1402640310

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/1358997

values:
nofollow
external text
//doi.org/10.3354%2Fdao002147

values:
/wiki/Natural_History_Museum
mw-redirect
Natural History Museum

values:
nofollow
external text
//doi.org/10.1007%2FBF00004787

values:
nofollow
external text
//doi.org/10.1007%2FBF00395589

values:
nofollow
external text
//doi.org/10.1098%2Frspb.2014.0479

values:
/wiki/New_England_Journal_of_Medicine
mw-redirect
New England Journal of Medicine

values:
nofollow
external text
//doi.org/10.1056%2FNEJMc1209382

values:
nofollow
external text
//doi.org/10.1111%2Facel.12487

values:
nofollow
external text
//www.worldcat.org/issn/1474-9726

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/27095483

values:
nofollow
external text
//doi.org/10.1111%2Ftra.12411

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/27161495

values:
nofollow
external text
//doi.org/10.1126%2Fscience.1133609

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/17095691

values: Category:CS1 maint: Explicit use of et al.

values:
nofollow
external text
//doi.org/10.1126%2Fscience.1134301

values:
nofollow
external text
//www.ncbi.nlm.nih.gov/pubmed/17095692

values:
/wiki/Oxford_Companion_to_Food
mw-redirect
Oxford Companion to Food

values: This citation requires a reference to the specific page or range of pages in which the material appears. (November 2010)

values:
nofollow
external text
http://www.american.edu/TED/urchin.htm

values: -moz-column-width: 30em; -webkit-column-width: 30em; column-width: 30em; list-style-type: decimal;

values:
nofollow
external text
http://www.marinespecies.org

values:
nofollow
http://spbase.org/
external text

values:
nofollow
external text
http://www.calurchin.org/index.html

values:
/wiki/File:Atlantic_cod.jpg
image
Atlantic cod

values:
/wiki/File:Pacific_oysters_01.jpg
image
Pacific oysters

values:
navbox-image
2
width:1px;padding:0px 0px 0px 2px

values:
/wiki/Aquaculture_of_salmon
mw-redirect
Aquaculture of salmon

values:
/wiki/World_fish_production
mw-redirect
World fish production

values: List of commercially important fish species

values:
/wiki/List_of_fishing_topics_by_subject
mw-redirect
List of fishing topics by subject

values:
/wiki/Fisheries_glossary
mw-redirect
Fisheries glossary

values: nowraplinks hlist collapsible autocollapse navbox-inner

values:
noprint metadata navbox
navigation
Portals
font-weight:bold;padding:0.4em 2em

values:
row
navbox-group
width:1%;text-align: left;

values:
nofollow
external text
http://eol.org/pages/1971

values: Global Biodiversity Information Facility

values:
nofollow
external text
https://www.gbif.org/species/221

values: National Center for Biotechnology Information

values:
nofollow
external text
https://d-nb.info/gnd/4054135-6

values: Category:Seafood in Native American cuisine

values: Category:Late Ordovician first appearances

values: Category:Extant Ordovician first appearances

values: Category:Wikipedia articles needing page number citations from November 2010

values: Category:Articles with 'species' microformats

values: Category:Articles containing Japanese-language text

values: Category:Commons category with local link different than on Wikidata

values: Category:Wikipedia articles with GND identifiers

values: Category:Articles containing video clips

values: Discussion about edits from this IP address [ctrl-alt-n]

values: A list of edits made from this IP address [ctrl-alt-y]

values: You are encouraged to create an account and log in; however, it is not mandatory

values:
/wiki/Sea_urchin
View the content page [ctrl-alt-c]
c

values: About the project, what you can do, where to find things

values: A list of recent changes in the wiki [ctrl-alt-r]

values: portal navigation p-interaction p-interaction-label

values: List of all English Wikipedia pages containing links to this page [ctrl-alt-j]

values: Recent changes in pages linked from this page [ctrl-alt-k]

values:
/wiki/Wikipedia:File_Upload_Wizard
Upload files [ctrl-alt-u]
u

values: A list of all special pages [ctrl-alt-q]

values: Permanent link to this revision of the page

values: Link to connected data repository item [ctrl-alt-g]

values: Printable version of this page [ctrl-alt-p]

values: portal navigation p-wikibase-otherprojects p-wikibase-otherprojects-label

values:
interlanguage-link interwiki-af
display: none;

values: قنفذ البحر – Arabic

values:
interlanguage-link interwiki-ast
display: none;

values:
interlanguage-link interwiki-az
display: none;

values:
interlanguage-link interwiki-azb
display: none;

values: Марскія вожыкі – Belarusian

values:
interlanguage-link interwiki-be
display: none;

values: Марскія вожыкі – Belarusian (Taraškievica orthography)

values:
interlanguage-link interwiki-be-x-old
display: none;

values: Морски таралежи – Bulgarian

values:
interlanguage-link interwiki-bg
display: none;

values:
interlanguage-link interwiki-bs
display: none;

values:
https://br.wikipedia.org/wiki/Teureug
Teureug – Breton
br
br
interlanguage-link-target

values:
interlanguage-link interwiki-br
display: none;

values:
interlanguage-link interwiki-ca
display: none;

values:
https://ceb.wikipedia.org/wiki/Tuyom
Tuyom – Cebuano
ceb
ceb
interlanguage-link-target

values:
interlanguage-link interwiki-ceb
display: none;

values:
interlanguage-link interwiki-cs
display: none;

values:
interlanguage-link interwiki-da
display: none;

values:
https://de.wikipedia.org/wiki/Seeigel
Seeigel – German
de
de
interlanguage-link-target

values:
interlanguage-link interwiki-de
display: none;

values:
interlanguage-link interwiki-nv
display: none;

values:
interlanguage-link interwiki-et
display: none;

values: Αχινός – Greek

values:
interlanguage-link interwiki-el
display: none;

values: Ведьсеель – Erzya

values:
interlanguage-link interwiki-myv
display: none;

values:
interlanguage-link interwiki-eo
display: none;

values:
interlanguage-link interwiki-eu
display: none;

values: توتیای دریایی – Persian

values:
interlanguage-link interwiki-fa
display: none;

values:
interlanguage-link interwiki-ga
display: none;

values:
interlanguage-link interwiki-gl
display: none;

values:
interlanguage-link interwiki-ko
display: none;

values: Ծովոզնիներ – Armenian

values:
interlanguage-link interwiki-hy
display: none;

values: जलसाही – Hindi

values:
interlanguage-link interwiki-hr
display: none;

values:
https://io.wikipedia.org/wiki/Ekino
Ekino – Ido
io
io
interlanguage-link-target

values:
interlanguage-link interwiki-io
display: none;

values:
interlanguage-link interwiki-ia
display: none;

values:
interlanguage-link interwiki-is
display: none;

values:
interlanguage-link interwiki-it
display: none;

values: קיפודי ים – Hebrew

values:
interlanguage-link interwiki-he
display: none;

values: ზღვის ზღარბები – Georgian

values:
interlanguage-link interwiki-ka
display: none;

values: Теңіз кірпілері – Kazakh

values:
interlanguage-link interwiki-kk
display: none;

values: Деңиз кирпилери – Kyrgyz

values:
interlanguage-link interwiki-ky
display: none;

values: Тангыж шӱлӹ – Western Mari

values:
interlanguage-link interwiki-mrj
display: none;

values:
interlanguage-link interwiki-la
display: none;

values:
interlanguage-link interwiki-lv
display: none;

values:
interlanguage-link interwiki-lt
display: none;

values:
interlanguage-link interwiki-hu
display: none;

values: Морски ежови – Macedonian

values:
interlanguage-link interwiki-mk
display: none;

values: കടൽച്ചേന – Malayalam

values:
interlanguage-link interwiki-ml
display: none;

values:
https://nl.wikipedia.org/wiki/Zee-egels
Zee-egels – Dutch
nl
nl
interlanguage-link-target

values:
interlanguage-link interwiki-nl
display: none;

values:
interlanguage-link interwiki-no
display: none;

values:
interlanguage-link interwiki-nn
display: none;

values:
interlanguage-link interwiki-oc
display: none;

values:
interlanguage-link interwiki-uz
display: none;

values:
interlanguage-link interwiki-pl
display: none;

values:
https://ro.wikipedia.org/wiki/Echinoide
Echinoide – Romanian
ro
ro
interlanguage-link-target

values:
interlanguage-link interwiki-ro
display: none;

values:
interlanguage-link interwiki-qu
display: none;

values: Морские ежи – Russian

values:
interlanguage-link interwiki-sco
display: none;

values:
interlanguage-link interwiki-scn
display: none;

values:
interlanguage-link interwiki-simple
display: none;

values:
interlanguage-link interwiki-sk
display: none;

values:
interlanguage-link interwiki-sl
display: none;

values: Морски јежеви – Serbian

values:
interlanguage-link interwiki-sr
display: none;

values:
interlanguage-link interwiki-sh
display: none;

values:
interlanguage-link interwiki-fi
display: none;

values:
interlanguage-link interwiki-sv
display: none;

values:
https://tl.wikipedia.org/wiki/Salungo
Salungo – Tagalog
tl
tl
interlanguage-link-target

values:
interlanguage-link interwiki-tl
display: none;

values: கடல் மூரை – Tamil

values:
interlanguage-link interwiki-ta
display: none;

values: เม่นทะเล – Thai

values:
interlanguage-link interwiki-th
display: none;

values:
interlanguage-link interwiki-tr
display: none;

values: Морські їжаки – Ukrainian

values:
interlanguage-link interwiki-uk
display: none;

values:
interlanguage-link interwiki-vi
display: none;

values:
interlanguage-link interwiki-war
display: none;

values:
interlanguage-link interwiki-zh-yue
display: none;

values: All languages (initial selection from common choices by you and others)

values: /static/images/wikimedia-button-1.5x.png 1.5x, /static/images/wikimedia-button-2x.png 2x

values: /static/images/poweredby_mediawiki_132x47.png 1.5x, /static/images/poweredby_mediawiki_176x62.png 2x

values: mediawiki ltr sitedir-ltr mw-hide-empty-elt ns-0 ns-subject page-Sea_urchin rootpage-Sea_urchin skin-vector action-view