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Akarotaxis
''Akarotaxis'' is a monotypic genus of marine ray-finned fish belonging to the family Bathydraconidae, the Antarctic dragonfish, its only species is ''Akarotaxis nudiceps''. They are found in the Southern Ocean along the continental shelf of Antarctica. Taxonomy ''Akarotaxis'' was first described as a genus in 1980 by the American ichthyologist Hugh Hamilton DeWitt and the French ichthyologist Jean-Claude Hureau. Its only species is ''Akarotaxis nudiceps'' which was described in 1916 as ''Bathydraco nudiceps'' by the British-born Australian zoologist Edgar Ravenswood Waite with the type locality given as Queen Mary Land off the Shackleton Ice Shelf. The type was collected by the Australasian Antarctic Expedition. The generic name compounds ''akaro'' meaning "short" or "small" with "taxis" which means "line" or "row", a reference to the short upper lateral line, which comprises lees than 10 tubular scales. The specific name ''nudiceps'' means "naked head", thought to be a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathydraconidae
The Bathydraconidae, or the Antarctic dragonfishes, are a family of marine ray-finned fishes, notothenioids belonging to the Perciform suborder Notothenioidei. The family comprises four genera. These fishes are endemic to deep waters off Antarctica. Taxonomy Bathydraconidae was first formally described as a family in 1913 by the English ichthyologist Charles Tate Regan in his report on the fishes collected on the Scottish National Antarctic Expedition to the Royal Society of Edinburgh. He used the genus '' Bathydraco'', which had been described by Albert Gunther in 1878 as a monotypic genus with '' B. antarctica'' as its type species, as the type genus. Molecular analyses have supported the split of bathydraconids into three clades; Bathydraconinae which includes ''Bathydraco'', '' Prionodraco'' and '' Racovitzia''; Gymnodraconinae which includes '' Gymnodraco'', '' Psilodraco'' and '' Acanthodraco''); and Cygnodraconinae including '' Cygnodraco'', '' Gerlachea'' and '' Parach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic Dragonfish
The Bathydraconidae, or the Antarctic dragonfishes, are a family of marine ray-finned fishes, notothenioids belonging to the Perciform suborder Notothenioidei. The family comprises four genera. These fishes are endemic to deep waters off Antarctica. Taxonomy Bathydraconidae was first formally described as a family in 1913 by the English ichthyologist Charles Tate Regan in his report on the fishes collected on the Scottish National Antarctic Expedition to the Royal Society of Edinburgh. He used the genus ''Bathydraco'', which had been described by Albert Gunther in 1878 as a monotypic genus with '' B. antarctica'' as its type species, as the type genus. Molecular analyses have supported the split of bathydraconids into three clades; Bathydraconinae which includes ''Bathydraco'', '' Prionodraco'' and ''Racovitzia''; Gymnodraconinae which includes '' Gymnodraco'', ''Psilodraco'' and ''Acanthodraco''); and Cygnodraconinae including '' Cygnodraco'', '' Gerlachea'' and ''Parachaenichth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hugh Hamilton DeWitt
Hugh Hamilton DeWitt (28 December 1933-5 January 1995) was an American ichthyologist, marine biologist and oceanographer. DeWitt was born on 28 December 1933 in San Jose, California, son of Carl Bryce Seligman, a country doctor, and Honor Pettit Seligman, a teacher of mathematics and Latin. His surname at birth was Seligman but at his father's urging he and his brothers changed their name to DeWitt in the 1950s, a name from their mother’s side of the family, as they had encountered mistaken preconceptions while attending High Schools in the eastern United States. His brothers were the theoretical physicist Bryce Seligman DeWitt, Lloyd Lewis DeWitt (1926-1988), who joined the United States Foreign Service and Hiram Pettit DeWitt (b.1936), a teacher. He grew up largely in California, leaving to attend high school at the Putney School in Vermont. He returned to California to enrol at Stanford University, gaining his Bachelor's degree in 1955, masters in 1960 and doctorate in 1966, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shackleton Ice Shelf
Shackleton Ice Shelf is an extensive ice shelf fronting the coast of East Antarctica from 95° E to 105° E. It extends for an along-shore distance of about , projecting seaward about in the western portion and in the east. It occupies an area of . It is part of Mawson Sea and separates the Queen Mary Coast to the west from the Knox Coast of Wilkes Land to the east. Discovery and naming The existence of this ice shelf was first made known by the USEE under Charles Wilkes who mapped a portion of it from the ''Vincennes'' in February 1840. It was explored by the Australian Antarctic Expedition under Douglas Mawson (1911–14) who named it for Sir Ernest Shackleton. The extent of the ice shelf was mapped in greater detail in 1955, using aerial photography obtained by US Navy Operation Highjump, 1946–47. Further mapping by the Soviet Expedition of 1956 showed the portion eastward of Scott Glacier to be a part of this ice shelf. Important Bird Area A 500 ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spawning
Spawn is the eggs and sperm released or deposited into water by aquatic animals. As a verb, ''to spawn'' refers to the process of releasing the eggs and sperm, and the act of both sexes is called spawning. Most aquatic animals, except for aquatic mammals and reptiles, reproduce through the process of spawning. Spawn consists of the reproductive cells (gametes) of many aquatic animals, some of which will become fertilized and produce offspring. The process of spawning typically involves females releasing ova (unfertilized eggs) into the water, often in large quantities, while males simultaneously or sequentially release spermatozoa (milt) to fertilize the eggs. Most fish reproduce by spawning, as do most other aquatic animals, including crustaceans such as crabs and shrimps, molluscs such as oysters and squid, echinoderms such as sea urchins and sea cucumbers, amphibians such as frogs and newts, aquatic insects such as mayflies and mosquitoes and corals, which are actually small ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bathydemersal
Demersal fish, also known as groundfish, live and feed on or near the bottom of seas or lakes (the demersal zone).Walrond Carl . "Coastal fish - Fish of the open sea floor"Te Ara - the Encyclopedia of New Zealand. Updated 2 March 2009 They occupy the sea floors and lake beds, which usually consist of mud, sand, gravel or rocks. In coastal waters they are found on or near the continental shelf, and in deep waters they are found on or near the continental slope or along the continental rise. They are not generally found in the deepest waters, such as abyssal depths or on the abyssal plain, but they can be found around seamounts and islands. The word ''demersal'' comes from the Latin ''demergere'', which means ''to sink''. Demersal fish are bottom feeders. They can be contrasted with pelagic fish which live and feed away from the bottom in the open water column. Demersal fish fillets contain little fish oil (one to four percent), whereas pelagic fish can contain up to 30 percent. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ross Sea
The Ross Sea is a deep bay of the Southern Ocean in Antarctica, between Victoria Land and Marie Byrd Land and within the Ross Embayment, and is the southernmost sea on Earth. It derives its name from the British explorer James Clark Ross who visited this area in 1841. To the west of the sea lies Ross Island and Victoria Land, to the east Roosevelt Island and Edward VII Peninsula in Marie Byrd Land, while the southernmost part is covered by the Ross Ice Shelf, and is about from the South Pole. Its boundaries and area have been defined by the New Zealand National Institute of Water and Atmospheric Research as having an area of . The circulation of the Ross Sea is dominated by a wind-driven ocean gyre and the flow is strongly influenced by three submarine ridges that run from southwest to northeast. The circumpolar deep water current is a relatively warm, salty and nutrient-rich water mass that flows onto the continental shelf at certain locations. The Ross Sea is covered with ice ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adelaide Island
Adelaide Island is a large, mainly ice-covered island, long and wide, lying at the north side of Marguerite Bay off the west coast of the Antarctic Peninsula. The Ginger Islands lie off the southern end. Mount Bodys is the easternmost mountain on Adelaide Island, rising to over 1,220 m. The island lies within the Argentine, British and Chilean Antarctic claims. History Adelaide Island was discovered in 1832 by a British expedition under John Biscoe. The island was first surveyed by the French Antarctic Expedition (1908–1910) under Jean-Baptiste Charcot. According to a contemporary source, the island was named by Biscoe himself in honour of Queen Adelaide of the United Kingdom. The Island has two bases on it. The old Adelaide Island base (also known as Base T) was set up by the Falkland Islands Dependencies Survey (FIDS), which later became the British Antarctic Survey. The Base was closed due to an unstable skiway and operations were moved to the new Rothera Resea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Standard Length
Fish measurement is the measuring of individual fish and various parts of their anatomies. These data are used in many areas of ichthyology, including taxonomy and fisheries biology. Overall length * Standard length (SL) is the length of a fish measured from the tip of the snout to the posterior end of the last vertebra or to the posterior end of the midlateral portion of the hypural plate. Simply put, this measurement excludes the length of the caudal (tail) fin. * Total length (TL) is the length of a fish measured from the tip of the snout to the tip of the longer lobe of the caudal fin, usually measured with the lobes compressed along the midline. It is a straight-line measure, not measured over the curve of the body. Standard length measurements are used with Teleostei (most bony fish), while total length measurements are used with Myxini (hagfish), Petromyzontiformes (lampreys), and (usually) Elasmobranchii (sharks and rays), as well as some other fishes. Total length measu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anal Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to lu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Fin
A dorsal fin is a fin located on the back of most marine and freshwater vertebrates within various taxa of the animal kingdom. Many species of animals possessing dorsal fins are not particularly closely related to each other, though through convergent evolution they have independently evolved external superficial fish-like body plans adapted to their marine environments, including most numerously fish, but also mammals such as cetaceans (whales, dolphins, and porpoises), and even extinct ancient marine reptiles such as various known species of ichthyosaurs. Most species have only one dorsal fin, but some have two or three. Wildlife biologists often use the distinctive nicks and wear patterns which develop on the dorsal fins of large cetaceans to identify individuals in the field. The bony or cartilaginous bones that support the base of the dorsal fin in fish are called ''pterygiophores''. Functions The main purpose of the dorsal fin is to stabilize the animal against rollin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ctenoid
A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which can also provide effective camouflage through the use of reflection and colouration, as well as possible hydrodynamic advantages. The term ''scale'' derives from the Old French , meaning a shell pod or husk. Scales vary enormously in size, shape, structure, and extent, ranging from strong and rigid armour plates in fishes such as shrimpfishes and boxfishes, to microscopic or absent in fishes such as eels and anglerfishes. The morphology of a scale can be used to identify the species of fish it came from. Scales originated within the jawless ostracoderms, ancestors to all jawed fishes today. Most bony fishes are covered with the cycloid scales of salmon and carp, or the ctenoid scales of perch, or the ganoid scales of sturgeons and gars. Cartilaginous fishes (sharks and rays) are covered with placoid scales. Some species ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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