Red urchin | |
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A group of Astropyga radiata seen in Kenya. | |
Scientific classification ![]() | |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Echinoidea |
Order: | Diadematoida |
Family: | Diadematidae |
Genus: | Astropyga |
Species: | A. radiata |
Binomial name | |
Astropyga radiata | |
Synonyms [1] | |
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Astropyga radiata, the red urchin, fire urchin, false fire urchin or blue-spotted urchin, is a species of sea urchin in the family Diadematidae. It is a large species with long spines and is found in the tropical Indo-Pacific region. It was first described in 1778 by the German naturalist Nathaniel Gottfried Leske.
Astropyga radiata is a large urchin with a test diameter of up to 20 cm (8 in), flattened or slightly concave on the aboral (upper) side. The spines are up to 4 cm (1.6 in) long and are grouped in five vertical clusters in between which are V-shaped areas with no spines corresponding to the interambulacral plates. These bare areas are red with lines of iridescent blue dots while the colour of the rest of the test and spines varies from reddish brown to purple, dark brown or nearly black. The spines are long and hollow; they are of two kinds, the shorter being venomous. The anal sac is prominent, brown with a dark tip. Juveniles have spines with transverse banding and this characteristic sometimes persists into adulthood. [2] [3]
Astropyga radiata is found in the Indo-Pacific Ocean at a maximum depth of about 70 metres (230 ft) but more normally at 10 to 30 metres (33 to 98 ft). Its range extends from the African coast to Hawaii and Australian waters. [1] It is often found in lagoons and bays where the substrate is sand, shingle or coral rubble. Sometimes many urchins collect together in one locality in dense aggregations. [2]
Astropyga radiata is mostly nocturnal and feeds by grazing on algae. The mouth is at the centre of the oral (under) surface where there are five powerful teeth in an arrangement known as an Aristotle's lantern. This urchin is light sensitive and can angle its spines towards an approaching threatening object. [3]
The sexes are separate in Astropyga radiata. Eggs and sperm are liberated into the water column. After fertilisation, the larvae are planktonic and develop through several stages before settling on the seabed and undergoing metamorphosis into a juvenile urchin. [3]
A number of crustaceans and fish live in association with this urchin. These include the commensal shrimps Periclimenes hirsutus and Stegopontonia commensalis and the crab Zebrida adamsii . Another crab, Dorippe frascone is a symbiont and carries the urchin on its back. [3] Certain juvenile fish also live among the spines including young emperor red snappers ( Lutjanus sebae ), cardinal fish (Apogonidae) and the zebra lionfish. [2]
Although not deadly to humans, these urchin's quills are quite venomous; capable of inflicting painful wounds. However, being a rather large and brightly colored species of urchin, it is relatively visible to divers, making injuries by accidentally stepping on one comparatively rare. Due to its beauty, it is loved by underwater photographers and some expert fish-keepers.
"Astropyga" comes from ancient Greek, astro meaning "star" and pyga "anus". Hence, it is named because of its star-shaped anus (or more precisely the star-shaped pattern around its anus).
"Radiata" comes from Latin and means "radiant", because of its colors and spines.
In English, it is also called star urchin, blue-spotted urchin, red sea urchin, or false fire urchin (different from the "true" fire urchin, Asthenosoma varium ).
It goes by the name of Roter (Diadem)Seeigel in German, Riccio rosso in Italian, Falso erizo de fuego in Spanish, and Oursin rouge in French.
Sea 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 hard shells (tests) are round and spiny, usually 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, triggerfish, and humans.
The Diadematidae are a family of sea urchins. Their tests are either rigid or flexible and their spines are long and hollow.
The diadema urchin or blue-black urchin is a species of tropical sea urchin, member of the Diadematidae family.
Echinothrix calamaris, known commonly as the banded sea urchin or double spined urchin among other vernacular names, is a species of sea urchin in the family Diadematidae.
The clearfin lionfish, also called the tailbar lionfish, radiata lionfish, fireworks fish or radial firefish, is a carnivorous, ray-finned fish with venomous spines that lives in the Indian and western Pacific Oceans. This is the only lionfish species which has spines without any markings. It can also be recognized by the pair of horizontal white stripes on its caudal peduncle.
Diadema setosum is a species of long-spined sea urchin belonging to the family Diadematidae. It is a typical sea urchin, with extremely long, hollow spines that are mildly venomous. D. setosum differs from other Diadema with five, characteristic white dots that can be found on its body. The species can be found throughout the Indo-Pacific region, from Australia and Africa to Japan and the Red Sea. Despite being capable of causing painful stings when stepped upon, the urchin is only slightly venomous and does not pose a serious threat to humans.
Algae eater, also called an algivore, is a common name for many bottom-dwelling or algae-eating species that feed on algae. Algae eaters are important for the fishkeeping hobby and many are commonly kept by hobbyists.
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.
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.
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.
Radiata may refer to:
Toxopneustes is a genus of sea urchins from the tropical Indo-Pacific. It contains four species. They are known to possess medically significant venom to humans on their pedicellariae. They are sometimes collectively known as flower urchins, after the most widespread and most commonly encountered species in the genus, the flower urchin. Species included in the genus are the following:
Dorippe frascone, the urchin crab or carrier crab, is a small species of crab in the family Dorippidae that was first described scientifically by J.F.W. Herbst, in 1785. It is found in the Red Sea and parts of the western and eastern Indian Ocean. It often has a symbiotic relationship with a long-spined sea urchin and carries one around on its carapace.
The blue blanquillo, Malacanthus latovittatus, also known as the banded blanquillo, striped blanquillo, false whiting, sand tilefish or eye of the sea, is a species of marine ray-finned fish, a tilefish belonging to the family Malacanthidae. It is found in the Indo-Pacific.
Diadema paucispinum, the long-spined sea urchin, is a species of sea urchin in the family Diadematidae. It is found in the western Indo-Pacific Ocean and in Hawaii and other east Pacific islands.
Brissus latecarinatus is a species of sea urchins of the Family Brissidae. Their armour is covered with spines. Brissus latecarinatus was first scientifically described in 1778 by Nathanael Gottfried Leske.
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.
Clypeaster humilis is a species of sea urchin in the Family Clypeasteridae. This species was first scientifically described in 1778 by the German biologist Nathanael Gottfried Leske. It occurs in the tropical Indo-Pacific region.
Parechinus angulosus, the Cape urchin, is a sea urchin in the family Parechinidae endemic to southern Africa.
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