| Diadema paucispinum | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Echinodermata |
| Class: | Echinoidea |
| Order: | Diadematoida |
| Family: | Diadematidae |
| Genus: | Diadema |
| Species: | D. paucispinum |
| Binomial name | |
| Diadema paucispinum A. Agassiz, 1863 [1] | |
| Synonyms [1] | |
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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.
Diadema paucispinum is a small sea urchin with very long, moveable spines which are slender and sharply pointed. They can be up to 25 cm (10 in) long and about four times the diameter of the test. The primary spines are bluish-black in colour, often with pale bands in younger individuals. The shorter secondary ones are brittle and venomous and easily break off in the skin. [2] There are photosensitive spots in the urchin's epidermis and if a shadow falls on the animal, it angles its secondary spines towards the intruder. These can cause a painful sting if they come into contact with bare skin. [2] Near the apex of the test is a clearly visible anus surrounded by an orange ring and raised on a small projection. Radiating from this are five narrow, bright blue lines. [2] [3]
There are two mitochondrial clades of Diadema paucispinum. One was originally considered to be limited to Hawaii but has now been found on Easter Island, Pitcairn, and Okinawa. The other one ranges from East Africa and Arabia to the Philippines and New Guinea. [4] In shallow parts of the Red Sea this sea urchin is found on calcareous rocky shelves a few feet under the surface where it uses its spines to wedge itself into crevices and hollows in the rock. [3] In Hawaii it is known as "wana" and is found on reef flats and gently shelving areas. [2]
Diadema paucispinum is nocturnal and grazes on filamentous algae as it crawls over the rocks. Despite its formidable defensive armoury, Diadema paucispinum is preyed on by triggerfishes. [2]
Skin contact with this sea urchin should be avoided. An injury caused by the secondary spines should first be soaked in hot water to deactivate the toxins and later vinegar may help soften the spines. Surgical removal of spine tips that remain in the skin is difficult because of their fragility. Left alone they may gradually be absorbed into the tissues. [2]
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 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.
Diadema is a genus of sea urchins of the family Diadematidae.
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.
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.
The long-spine porcupinefish, also known as the freckled porcupinefish among other vernacular names, is a species of marine fish in the family Diodontidae.
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.
Diademichthys lineatus, commonly known as the long-snout clingfish or urchin clingfish, is a species of marine fish in the family Gobiesocidae.
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.
Toxopneustes pileolus, commonly known as the flower urchin, is a widespread and commonly encountered species of sea urchin from the Indo-West Pacific. It is considered highly dangerous, as it is capable of delivering extremely painful and medically significant stings when touched. It inhabits coral reefs, seagrass beds, and rocky or sandy environments at depths of up to 90 m (295 ft). It feeds on algae, bryozoans, and organic detritus.
Zebrida adamsii is a distinctively striped species of crab that lives in association with a sea urchin in the Indo-Pacific region. It is cryptically coloured with vertical stripes and has special adaptations to its legs to enable it to cling to its host's spines.
Asthenosoma varium is a sea urchin. Growing up to 25 cm (10 in) in diameter, it lives on sand and rubble sea bottoms in the Indo-Pacific, from the Red Sea to Australia and Southern Japan. Its venom tipped spines, with distinctive globular swellings below the tip, can inflict a painful sting if handled; the pain lasts as long as several hours. This capacity, perhaps coupled with its reddish-brown colour, has given it the common name fire urchin; other commonly used names are Pacific fire urchin, elusive sea urchin, variable fire urchin, and electric sea urchin.
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:
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.
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.
Cidaris cidaris is a species of sea urchin commonly known as the long-spine slate pen sea urchin. It is found in deep water in the eastern Atlantic Ocean and the Mediterranean Sea.
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.
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.
Paracorynactis is a genus of corallimorphs from the western Indo-West Pacific. They are specialized predators of echinoderms, and are notable for preying on the destructive crown-of-thorns starfish among others. The genus is monotypic with the single species, Paracorynactis hoplites.