Aspidodiadema jacobyi | |
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Echinodermata |
Class: | Echinoidea |
Order: | Aspidodiadematoida |
Family: | Aspidodiadematidae |
Genus: | Aspidodiadema |
Species: | A. jacobyi |
Binomial name | |
Aspidodiadema jacobyi A. Agassiz, 1880 [1] | |
Aspidodiadema jacobyi is a small sea urchin in the family Aspidodiadematidae. It lives in tropical seas at great depths. Aspidodiadema jacobyi was first scientifically described in 1880 by Alexander Emanuel Agassiz, an American scientist. [2]
Aspidodiadema jacobyi has a globular hard test or shell protecting the inner organs. The mouth has 10 buccal plates and small rounded buccal notches and is on the oral (bottom) surface which is slightly flattened. The aboral (top) surface has a small coronal ring of tubercles surrounding the anus. The test is composed of 5 radial ambulacral sets of 3 plates, separated by 5 ambulacral grooves. There are rows of pairs of pores between the ambulacral areas through which the tube feet protrude. Every third row of plates is larger than the other 2 and has a zig-zag row of large primary tubercles. This row does not extend quite as far as the other 2 rows of plates which have similar primary tubercles set serially in a straight line. These large tubercles are perforate and crenulate. There are smaller, secondary tubercles at the edge of the plates. Slender, flexible spines articulate with all these tubercles. These spines are hollow and have bridging structures across their lumina with minute needle-like pillars. The test has green tubercles with purple interambulacral areas. [3]
Aspidodiadema jacobyi is found in the bathyal zone at depths of over 1,000 metres (3,300 ft) in the Caribbean Sea and Gulf of Mexico. Its range extends from the Bahamas and West Indies to Colombia, Nicaragua and Mexico. [1]
Little was known about the reproductive biology of deep-water sea urchins, therefore a study was undertaken using Aspidodiadema jacobyi as a model. This species is dioecious with individuals being either male or female. Mature individuals were gathered during the spring on a number of occasions spanning several years. They were collected in the Bahamas by suction at depths of 500 to 750 metres (1,640 to 2,460 ft) and were kept in containers in the laboratory. Attempts were made to initiate spawning but these were successful on only two occasions. The eggs measured 94–100μm and had a yolk so that newly hatched larvae do not need to feed at first. It was suggested that in the open sea this would allow the larvae to disperse in ocean currents, surviving in cold waters where little food is available. [4] Alternatively, another study found that the eggs are surrounded by mucus through which the sperm, which have unusually elongated heads, must penetrate. The eggs clump together and may adhere in a viscous mass to the adult's spines and be brooded there. The sperm also form a mucous mass, and it may be that a form of pseudo-copulation takes place with the pressing together of the gamete masses of adjacent individuals. [5] In the laboratory, embryos developed over a period of 5 months into echinopluteus larvae measuring over 3000μm which were fed on unicellular algae. During their early stages the larvae developed 2 and then 4 larval arms before the mouth developed at about 11 days. Three further pairs of long arms developed over the next 30 days, after which a posterior process and a ciliated ring appeared successively. At 75 days a rudimentary echinus appeared and at 116 days, podia were apparent. None of the larvae completed metamorphosis into a juvenile and it was suggested that this may have been because the process needed to be initiated by chemical stimuli that were absent in this in vitro experiment. [4]
The Aspidodiadematidae are a family of sea urchins.
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.
Hemicentrotus pulcherrimus is a species of sea urchin, the only one in the monotypic genus Hemicentrotus. It was first described by the American engineer and marine zoologist Alexander Agassiz in 1864 as Psammechinus pulcherrimus. Its range extends along the coasts of Korea, Taiwan and China, and in Japan from Kyūshū to Ishikari Bay. An edible species, it is harvested from Kyūshū to Fukui, in the Sea of Japan.
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The Parechinidae are a family of sea urchins in the class Echinoidea.
Psammechinus miliaris is a species of sea urchin in the family Parechinidae. It is sometimes known as the green sea urchin or shore sea urchin. It is found in shallow areas of the eastern Atlantic Ocean and the North Sea.
Toxopneustidae is a family of globular sea urchins in the class Echinoidea.
The Camarodonta are an order of globular sea urchins in the class Echinoidea. The fossil record shows that camarodonts have been in existence since the Lower Cretaceous.
Sterechinus is a genus of sea urchins in the family Echinidae. All living members of the genus are found in the waters around Antarctica but the first species described in the genus was a fossil and was found in Europe.
Sterechinus neumayeri, the Antarctic sea urchin, is a species of sea urchin in the family Echinidae. It is found living on the seabed in the waters around Antarctica. It has been used as a model organism in the fields of reproductive biology, embryology, ecology, physiology and toxicology.
Heterocentrotus is a genus of the familia Echinometridae. They are mainly found in the Indo-Pacific basin, especially in Reunion or Hawaii. This genus appeared in the Miocene and spread throughout the warm Indo-Pacific.
Aspidodiadema tonsum is a species of sea urchin of the family Aspidodiadematidae. Their armour is covered with spines. It is placed in the genus Aspidodiadema and lives in the sea. Aspidodiadema tonsum was first scientifically described in 1879 by Alexander Emanuel Agassiz.
Calveriosoma gracile is a species of sea urchin in the order Echinothurioida. It is a deep water species and is found on the seabed in western parts of the Pacific Ocean at depths of 200 to 800 metres.
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.
Cidaris blakei is a species of sea urchins of the family Cidaridae. Its armour is covered with spines of three types, one unique type being extended and fan-like, making it easily recognized. Alexander Agassiz first described it scientifically in 1878. It is present on the seabed in deep waters in the Gulf of Mexico and the Bahamas.
Pseudocentrotus depressus, commonly known as the pink sea urchin, is a species of sea urchin, one of only two species in the genus Pseudocentrotus. It was first described in 1864 by the American marine zoologist Alexander Agassiz as Toxocidaris depressus, having been collected during the North Pacific Exploring and Surveying Expedition undertaken by Captain Cadwalader Ringgold and later Captain John Rodgers.
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.
Aspidodiadema is a genus of echinoderms belonging to the family Aspidodiadematidae. The species of this genus are found in the Indo-Pacific and Caribbean.
Pourtalesia miranda, commonly known as the wonderful sea urchin, is a species of sea urchin in the family Pourtalesiidae. It is found at abyssal depths in the Atlantic Ocean.