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Acrocnida Brachiata
''Acrocnida brachiata'', the sand burrowing brittlestar, is a species of brittle star in the family Amphiuridae. It occurs on the seabed in the northeastern Atlantic Ocean and the North Sea, living semi-buried in the sand with only its arm tips projecting. Description ''Acrocnida brachiata'' has a flat disc up to in diameter and five slender, clearly-demarcated, articulated arms up to in length. It is greyish-brown in colour. It can be distinguished from other similar species by the transverse furrows in the plates at the bases of the arms, the ventral scales bearing small tubercles and by the presence of an outer mouth papilla which is quite distinct from the paired papillae inside the mouth. The arms, which like other brittle stars flex sideways rather than up and down, have a pair of tentacle scales on each joint as well as numerous spines. Distribution and habitat ''A. brachiata'' occurs in the northeastern Atlantic Ocean and North Sea. It is common round the coasts of t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animalia
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and the deuterostomes, containing the echinode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinodermata
An echinoderm () is any member of the phylum Echinodermata (). The adults are recognisable by their (usually five-point) radial symmetry, and include starfish, brittle stars, sea urchins, sand dollars, and sea cucumbers, as well as the sea lilies or "stone lilies". Adult echinoderms are found on the sea bed at every ocean depth, from the intertidal zone to the abyssal zone. The phylum contains about 7,000 living species, making it the second-largest grouping of deuterostomes, after the chordates. Echinoderms are the largest entirely marine phylum. The first definitive echinoderms appeared near the start of the Cambrian. The echinoderms are important both ecologically and geologically. Ecologically, there are few other groupings so abundant in the biotic desert of the deep sea, as well as shallower oceans. Most echinoderms are able to reproduce asexually and regenerate tissue, organs, and limbs; in some cases, they can undergo complete regeneration from a single limb. Geolo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiuroidea
Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to in length on the largest specimens. The Ophiuroidea contain two large clades, Ophiurida (brittle stars) and Euryalida (basket stars). Over 2,000 species of brittle stars live today. More than 1,200 of these species are found in deep waters, greater than 200 m deep. Range The ophiuroids diverged in the Early Ordovician, about 500 million years ago. Ophiuroids can be found today in all of the major marine provinces, from the poles to the tropics. Basket stars are usually confined to the deeper parts of this range; Ophiuroids are known even from abyssal (>6,000 m) depths. However, brittle stars are also common members of reef communities, where the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ophiurida
The Ophiurida are an order of echinoderms within the class Ophiuroidea. It includes the vast majority of living brittle stars. Characteristics Ophiurida have bursae for respiration and excretion, and dorsal and ventral arm shields are present and usually well developed. Arms are unbranched and incapable of coiling vertically. Most are five-armed, some with 4 or 6 arms as an abnormality, but others properly bear six or seven arms. The madreporite is on the oral surface. The digestive glands are entirely within the central disc. They move their arms side to side by means of ball-and-socket joints. Tropical species tend to contrast color from the environment, but most others prefer to blend in. These biochromes do not include echinochromes. Systematics and phylogeny There is currently no consensus as to the subdivision of the Ophiurida. The order has been divided into the following suborders and infraorders * Ophiomyxina * Ophiurina ** Hemieuryalina ** Chilophiurina ** Gna ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnathophiurina
The Gnathophiurina are a group of Ophiuroidea mostly treated as suborder (but at first as an order Gnathophiurida, and sometimes as infraorder of OphiurinaSmith, A.B.; Paterson, G.L.J. . Ophiuroid phylogeny and higher taxonomy: morphological, molecular and palaeontological perspectives. Zool. J. Linn. Soc. 114 (1995) or not used at all). Families * Amphilepididae Matsumoto, 1915 * Amphiuridae Ljungman, 1867 * Ophiactidae Matsumoto, 1915 * Ophiocomidae Ljungman, 1867 * Ophionereididae Ljungman, 1867 * Ophiothricidae Ljungman, 1867 References Gnathophiurina, Ophiurida {{ophiuroidea-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amphiuridae
Amphiuridae (commonly called long-armed burrowing brittle stars or burrowing brittle stars) are a large family of brittle stars of the suborder Gnathophiurina. Some species are used to study echinoderm development (e.g. '' Amphipholis kochii'' and '' Amphioplus abditus'') and bioluminescence (the dwarf brittle star, ''Amphipholis squamata''). Characteristics Amphiuridae are generally small brittlestars. Their jaws are always with two apical papillae at the tip, and one or more papillae on each side. Systematics and phylogeny Amphiuridae are the most diverse family of Ophiurida with over 200 species. The family contains the following genera: In addition, two extinct genera are known: * † '' Deckersamphiura'' Jagt, 2000 * † '' Xanthamphiura'' Hess 1970 Image:Amphiodia pulchella.jpg, '' Amphiodia pulchella'' Image:Amphioplus thrombodes.jpg, '' Amphioplus thrombodes'' Image:Ophiocentrus aspera.jpg, '' Ophiocentrus aspera'' Image:Amphipholis squamata Réunion.jpg, '' Amphipho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrocnida
''Acrocnida'' is a genus of brittle stars in the family Amphiuridae. The genus contains three members: '' Acrocnida brachiata, Acrocnida semisquamata,'' and ''Acrocnida spatulispina.'' There has also been observed hybridization between both '' Acrocnida brachiata'' and ''Acrocnida spatulispina'.'' It is a fairly common genus, usually found along the coasts of Northwestern Europe, but with some species like semisquamata appearing around West Africa. Members of this genus primarily prefer intertidal and sub-tidal habitats, and they are they are less likely to be found in intertidal areas by comparison. This genus was not officially classified until 1926, by T. Gislén. One study found that due to the increased calcification that '' Acrocnida brachiata'' causes could be a potential source of Carbon Dioxide for not only the warm, shallow environments they live in, but also for the atmosphere. Species The World Register of Marine Species lists the following species. * '' Acrocnida br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Montagu (naturalist)
George Montagu (1753 – 20 June 1815) was an English army officer and naturalist. He was known for his pioneering '' Ornithological Dictionary'' of 1802, which for the first time accurately defined the status of Britain's birds. He is remembered today for species such as the Montagu's harrier, named for him. Life and work George Montagu was born to James Montagu (1713–1790), who was great-great-grandson of Lord James Montagu (d. 1665), who was younger son of Henry Montagu, 1st Earl of Manchester. Montagu is best known for his '' Ornithological Dictionary'' (1802) and his contributions to early knowledge of British birds. He showed that many previously accepted species were invalid, either because they were birds in summer or winter plumage or males and females of the same species. His study of harriers resulted in the discovery that the Montagu's harrier was breeding in southern England. He was also involved in the first British records of cirl bunting, whose breeding range ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brittle Star
Brittle stars, serpent stars, or ophiuroids (; ; referring to the serpent-like arms of the brittle star) are echinoderms in the class Ophiuroidea, closely related to starfish. They crawl across the sea floor using their flexible arms for locomotion. The ophiuroids generally have five long, slender, whip-like arms which may reach up to in length on the largest specimens. The Ophiuroidea contain two large clades, Ophiurida (brittle stars) and Euryalida (basket stars). Over 2,000 species of brittle stars live today. More than 1,200 of these species are found in deep waters, greater than 200 m deep. Range The ophiuroids diverged in the Early Ordovician, about 500 million years ago. Ophiuroids can be found today in all of the major marine provinces, from the poles to the tropics. Basket stars are usually confined to the deeper parts of this range; Ophiuroids are known even from abyssal (>6,000 m) depths. However, brittle stars are also common members of reef communities, where t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthos
Benthos (), also known as benthon, is the community of organisms that live on, in, or near the bottom of a sea, river, lake, or stream, also known as the benthic zone.Benthos from the Census of Antarctic Marine Life website This community lives in or near marine or freshwater sedimentary environments, from s along the , out to the , and t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echinocardium Cordatum
''Echinocardium cordatum'', also known as the common heart urchin or the sea potato, is a sea urchin in the family (biology), family Loveniidae. It is found in sub-tidal regions in the NE Atlantic. Other un-named species have been identified as this species from temperate seas around the world. It lives buried in the sandy sea floor. Description The sea potato is a heart-shaped urchin clothed in a dense mat of furrowed yellowish spines which grow from tubercles and mostly point backwards. The upper surface is flattened and there is an indentation near the front. This urchin is a fawn colour but the Test (biology), tests that are found on the strandline have often lost their spines and are white. During life, the spines trap air which helps prevent asphyxiation for the buried urchin. The Ambulacrum (anatomy), ambulacra form a broad furrow in a star shape extending down the sides of the test. There are two series each of two rows of tube feet. The test reaches from six to nine cent ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acrocnida Spatulispina
''Acrocnida'' is a genus of brittle stars in the family Amphiuridae. The genus contains three members: '' Acrocnida brachiata, Acrocnida semisquamata,'' and ''Acrocnida spatulispina.'' There has also been observed hybridization between both '' Acrocnida brachiata'' and ''Acrocnida spatulispina'.'' It is a fairly common genus, usually found along the coasts of Northwestern Europe, but with some species like semisquamata appearing around West Africa. Members of this genus primarily prefer intertidal and sub-tidal habitats, and they are they are less likely to be found in intertidal areas by comparison. This genus was not officially classified until 1926, by T. Gislén. One study found that due to the increased calcification that '' Acrocnida brachiata'' causes could be a potential source of Carbon Dioxide for not only the warm, shallow environments they live in, but also for the atmosphere. Species The World Register of Marine Species lists the following species. * '' Acrocnida ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
