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Cygnodraco Mawsoni
Mawson's dragonfish (''Cygnodraco mawsoni'') is a species of Antarctic dragonfish native to the Southern Ocean around Antarctica. It is found at depths of from over the continental shelf. This species is the only known member of its genus. Taxonomy Mawson’s dragonfish was first formally described in 1916 by the British-born Australian ichthyologist Edgar Ravenswood Waite with the type locality given as Queen Mary Land off Drygalski Island where it was collected by the Australian Antarctic Expedition. Waite described it as the only species in a monotypic genus. The genus name is a combination of ''cygnus'' meaning “swan”, an allusion Waite did not explain but may be a reference to the somewhat duck-bill shaped snout, and ''draco'' which means “dragon”, a common suffix used In Notothenioid fishes. The specific name honours the Australian geologist Douglas Mawson who led the Australasian Antarctic Expedition. Description Mawson’s dragonfish has a slender, naked b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edgar Ravenswood Waite
Edgar Ravenswood Waite (5 May 1866 – 19 January 1928) was a British/Australian zoologist, ichthyologist, herpetologist, and ornithologist. Waite was born in Leeds, Yorkshire, England, the second son of John Waite, a bank clerk, and his wife Jane, ''née'' Vause. Waite was educated at Leeds Parish Church Middle Class School and at the Victoria University of Manchester. In 1888 he was appointed sub-curator of the Leeds Museum and three years later was made curator. On 7 April 1892 Waite married Rose Edith Green at St. Matthew's parish church, Leeds. In 1893 Waite became zoologist at the Australian Museum, Sydney, he was the Fish Curator there from 1893 to 1906. Waite accompanied Charles Hedley of the Australian Museum on the 1896 ''Funafuti Coral Reef Boring Expedition of the Royal Society'' under Professor William Sollas and Professor Edgeworth David. Following the expedition to Funafuti in the Ellice Islands (now known as Tuvalu) Waite published an account of ''The mammals, ... [...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] |
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] |
Polychaetes
Polychaeta () is a paraphyletic class of generally marine annelid worms, commonly called bristle worms or polychaetes (). Each body segment has a pair of fleshy protrusions called parapodia that bear many bristles, called chaetae, which are made of chitin. More than 10,000 species are described in this class. Common representatives include the lugworm (''Arenicola marina'') and the sandworm or clam worm ''Alitta''. Polychaetes as a class are robust and widespread, with species that live in the coldest ocean temperatures of the abyssal plain, to forms which tolerate the extremely high temperatures near hydrothermal vents. Polychaetes occur throughout the Earth's oceans at all depths, from forms that live as plankton near the surface, to a 2- to 3-cm specimen (still unclassified) observed by the robot ocean probe ''Nereus'' at the bottom of the Challenger Deep, the deepest known spot in the Earth's oceans. Only 168 species (less than 2% of all polychaetes) are known from fresh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gammarids
Gammaridae is a family of amphipods. In North America they are included among the folk taxonomic category of " scuds", and otherwise gammarids is usually used as a common name. They have a wide distribution, centered on Eurasia, and are euryhaline as a lineage, inhabiting fresh to marine waters. Systematics The Gammaridae were for a long time used as a "wastebin taxon", which included numerous genera of gammaridean amphipods that since then have been removed to their own families, such as the Anisogammaridae, Melitidae, Niphargidae. The following genera are currently listed in the family: *'' Akerogammarus'' Derzhavin & Pjatakova, 1967 *'' Albanogammarus'' Ruffo, 1995 *'' Amathillina'' G. O. Sars, 1894 *'' Axelboeckia'' Stebbing, 1899 *'' Baku'' Karaman & Barnard, 1979 *'' Cephalogammarus'' Karaman & Barnard, 1979 *'' Chaetogammarus'' Martynov, 1924 *'' Comatogammarus'' Stock, 1981 *'' Condiciogammarus'' G. Karaman, 1984 *'' Dershavinella'' Birstein, 1938 *''Dikerogammarus ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crangon Antarcticus
''Crangon'' is a genus of shrimp. Distribution ''Crangon'' species are found exclusively in the Northern Hemisphere, with most of the species occurring in the northern Pacific Ocean. '' C. septemspinosa'' is the only species in the genus to occur in the north-western Atlantic Ocean, while in the north-eastern Atlantic, '' C. crangon'' and '' C. allmani'' occur. With the exception of the important commercial species ''C. crangon'', however, the distributions of ''Crangon'' species are poorly characterised. The greater number of species in the Pacific Ocean is thought to indicate that the genus originated in the Pacific. Species ''Crangon'' contains the following extant species: *'' Crangon affinis'' De Haan, 1849 *'' Crangon alaskensis'' Lockington, 1877 *'' Crangon alba'' Holmes, 1900 *'' Crangon allmani'' Kinahan, 1860 *''Crangon amurensis'' Bražnikov, 1907 *''Crangon capensis'' Stimpson, 1860 *''Crangon cassiope'' De Man, 1906 *''Crangon crangon'' (Linnaeu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Decapoda
The Decapoda or decapods (literally "ten-footed") are an order of crustaceans within the class Malacostraca, including many familiar groups, such as crabs, lobsters, crayfish, shrimp and prawns. Most decapods are scavengers. The order is estimated to contain nearly 15,000 species in around 2,700 genera, with around 3,300 fossil species. Nearly half of these species are crabs, with the shrimp (about 3,000 species) and Anomura including hermit crabs, porcelain crabs, squat lobsters (about 2500 species) making up the bulk of the remainder. The earliest fossil decapod is the Devonian ''Palaeopalaemon''. Anatomy Decapods can have as many as 38 appendages, arranged in one pair per body segment. As the name Decapoda (from the Greek , ', "ten", and , '' -pod'', "foot") implies, ten of these appendages are considered legs. They are the pereiopods, found on the last five thoracic segments. In many decapods, one pair of these "legs" has enlarged pincers, called chelae, with the legs be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trematomus
''Trematomus'' is a genus of marine ray-finned fishes, belonging to the family Nototheniidae, the notothens or cod icefishes. These fishes occur in the Southern Ocean. Taxonomy ''Trematomus'' was first described as a genus in 1902 by the Belgian-born British ichthyologist George Albert Boulenger when he described four new species of notothen from specimens collected on the ''Southern Cross'' Expedition. In 1938 ''John Roxborough Norman'' designated ''T. newnesi'' as the type species, this being the species described first in Boulenger’s text. In 1982 Arkady Vladimirovich Balushkin created the new genus ''Pseudotrematomus'', in which he placed all the species in ''Trematomus'' other than ''T. newnesi'', but this classification has not been widely accepted. Some authorities place this genus in the subfamily Trematominae, but the 5th edition of '' Fishes of the World'' does not include subfamilies in the Nototheniidae. The generic name ''Trematomus'' is made up of ''trema'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthopelagic
The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of the larger profundal zone. Being just above the ocean floor, the demersal zone is variable in depth and can be part of the photic zone where light can penetrate, and photosynthetic organisms grow, or the aphotic zone, which begins between depths of roughly and extends to the ocean depths, where no light penetrates. Fish The distinction between demersal species of fish and pelagic species is not always clear cut. The Atlantic cod (''Gadus morhua'') is a typical demersal fish, but can also be found in the open water column, and the Atlantic herring (''Clupea harengus'') is predominantly a pelagic species but forms large aggregations near the seabed when it spawns on banks of gravel. Two types of fish inhabit the demersal zone: those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthic
The benthic zone is the ecological region at the lowest level of a body of water such as an ocean, lake, or stream, including the sediment surface and some sub-surface layers. The name comes from ancient Greek, βένθος (bénthos), meaning "the depths." Organisms living in this zone are called benthos and include microorganisms (e.g., bacteria and fungi) as well as larger invertebrates, such as crustaceans and polychaetes. Organisms here generally live in close relationship with the substrate and many are permanently attached to the bottom. The benthic boundary layer, which includes the bottom layer of water and the uppermost layer of sediment directly influenced by the overlying water, is an integral part of the benthic zone, as it greatly influences the biological activity that takes place there. Examples of contact soil layers include sand bottoms, rocky outcrops, coral, and bay mud. Description Oceans The benthic region of the ocean begins at the shore line (intertidal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weddell Sea
The Weddell Sea is part of the Southern Ocean and contains the Weddell Gyre. Its land boundaries are defined by the bay formed from the coasts of Coats Land and the Antarctic Peninsula. The easternmost point is Cape Norvegia at Princess Martha Coast, Queen Maud Land. To the east of Cape Norvegia is the King Haakon VII Sea. Much of the southern part of the sea is covered by a permanent, massive ice shelf field, the Filchner-Ronne Ice Shelf. The sea is contained within the two overlapping Antarctic territorial claims of Argentine Antarctica, the British Antarctic Territory, and also resides partially within the Antarctic Chilean Territory. At its widest the sea is around across, and its area is around . Various ice shelves, including the Filchner-Ronne Ice Shelf, fringe the Weddell sea. Some of the ice shelves on the east side of the Antarctic Peninsula, which formerly covered roughly of the Weddell Sea, had completely disappeared by 2002. The Weddell Sea has been deemed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Measurement
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 meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
