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Pseudochaenichthys
''Pseudochaenichthys'' is a monotypic genus of marine ray-finned fish belonging to the family Channichthyidae, the crocodile icefishes. Its only member is ''Pseudochaenichthys georgianus'', the South Georgia icefish, which is found in the Southern Ocean. Taxonomy ''Pseudochaenichthys'' was first described as a genus in 1937 by the English ichthyologist John Roxborough Norman when he was describing its only species ''Pseudochaenichthys georgianus''. The type locality of ''P. georgianus'' is South Georgia Island. The genus name is a compound of ''pseudo'' which means "false" and ''Chaenichthys'', an alternative spelling for '' Channichthys'', probably an allusion to its similarity of fishes in that genus. The specific name ''georgianus'' means that it belongs to (South) Georgia. Description ''Pseudochaenichthys'', the South Georgia icefish, is a dark greyish-green species with blackish first dorsal and pelvic fins. The pelvic fins have white outer borders. The dorsal fin has 7 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crocodile Icefish
The crocodile icefish or white-blooded fish comprise a family (Channichthyidae) of notothenioid fish found in the Southern Ocean around Antarctica. They are the only known vertebrates to lack hemoglobin in their blood as adults. Icefish populations are known to reside in the Atlantic and Indian sectors of the Southern Ocean, as well as the continental shelf waters surrounding Antarctica. Water temperatures in these regions remain relatively stable, generally ranging from . One icefish, ''Champsocephalus esox,'' is distributed north of the Antarctic Polar Frontal Zone. At least 16 species of crocodile icefish are currently recognized, although eight additional species have been proposed for the icefish genus ''Channichthys.'' In February 2021, scientists discovered and documented a breeding colony of ''Neopagetopsis ionah'' icefish estimated to have 60 million active nests across an area of approximately 92 square miles at the bottom of the Weddell Sea in Antarctica. The majority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Channichthyidae
The crocodile icefish or white-blooded fish comprise a family (Channichthyidae) of notothenioid fish found in the Southern Ocean around Antarctica. They are the only known vertebrates to lack hemoglobin in their blood as adults. Icefish populations are known to reside in the Atlantic and Indian sectors of the Southern Ocean, as well as the continental shelf waters surrounding Antarctica. Water temperatures in these regions remain relatively stable, generally ranging from . One icefish, ''Champsocephalus esox,'' is distributed north of the Antarctic Polar Frontal Zone. At least 16 species of crocodile icefish are currently recognized, although eight additional species have been proposed for the icefish genus ''Channichthys.'' In February 2021, scientists discovered and documented a breeding colony of ''Neopagetopsis ionah'' icefish estimated to have 60 million active nests across an area of approximately 92 square miles at the bottom of the Weddell Sea in Antarctica. The majority ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Roxborough Norman
John Roxborough Norman (1898, Wandsworth, London – 26 May 1944, Berkhamsted, Hertfordshire) was an English ichthyologist. He started as a clerk in a bank. His lifetime affliction with rheumatic fever began during his military service during the First World War. He entered the British Museum in 1921 where he worked for Charles Tate Regan (1878-1943). From 1939 to 1944, he was in charge of the Natural History Museum at Tring as the Curator of Zoology. Norman was the author of, among others, ''A History of Fishes'' (1931) and ''A Draft Synopsis of the Orders, Families and Genera of Recent Fishes'' (1957). He was considered closer to Albert Günther (1830-1914) than to Regan. See also *:Taxa named by John Roxborough Norman References Aldemaro Romero Home Page (Archived on 14 September 2006) *Translated from the French Wikipedia article 1898 births 1944 deaths English ichthyologists People from Wandsworth 20th-century British zoologists British military personnel of World War ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Total 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 me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Of The Southern Ocean
Fish are Aquatic animal, aquatic, craniate, gill-bearing animals that lack Limb (anatomy), limbs with Digit (anatomy), digits. Included in this definition are the living hagfish, lampreys, and Chondrichthyes, cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of living fish species are ray-finned fish, belonging to the class Actinopterygii, with around 99% of those being teleosts. The earliest organisms that can be classified as fish were soft-bodied chordates that first appeared during the Cambrian period. Although they lacked a vertebrate, true spine, they possessed notochords which allowed them to be more agile than their invertebrate counterparts. Fish would continue to evolve through the Paleozoic era, diversifying into a wide variety of forms. Many fish of the Paleozoic developed placodermi, external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monotypic Fish Genera
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa. Examples Just as the term ''monotypic'' is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within a family. Some examples of monotypic groups are: Plants * In the order Amborellales, there is only one family, Amborellaceae and there is only one genus, '' Amborella'', and in this genus there is only one species, namely ''Amborella trichopoda.' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trawling
Trawling is a method of fishing that involves pulling a fishing net through the water behind one or more boats. The net used for trawling is called a trawl. This principle requires netting bags which are towed through water to catch different species of fishes or sometimes targeted species. Trawls are often called towed gear or dragged gear. The boats that are used for trawling are called trawlers or draggers. Trawlers vary in size from small open boats with as little as 30 hp (22 kW) engines to large factory trawlers with over 10,000 hp (7.5 MW). Trawling can be carried out by one trawler or by two trawlers fishing cooperatively (pair trawling). Trawling can be contrasted with trolling. While trawling involves a net and is typically done for commercial usage, trolling instead involves a reed, rod and a bait or a lure and is typically done for recreational purposes. Trawling is also commonly used as a scientific sampling, or survey, method. Bottom vs. midwater trawling ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bycatch
Bycatch (or by-catch), in the fishing industry, is a fish or other marine species that is caught unintentionally while fishing for specific species or sizes of wildlife. Bycatch is either the wrong species, the wrong sex, or is undersized or juveniles of the target species. The term "bycatch" is also sometimes used for untargeted catch in other forms of animal harvesting or collecting. Non- marine species (freshwater fish not saltwater fish) that are caught (either intentionally or unintentionally) but regarded as generally "undesirable" are referred to as "rough fish" (mainly US) and " coarse fish" (mainly UK). In 1997, the Organisation for Economic Co-operation and Development (OECD) defined bycatch as "total fishing mortality, excluding that accounted directly by the retained catch of target species". Bycatch contributes to fishery decline and is a mechanism of overfishing for unintentional catch. The average annual bycatch rate of pinnipeds and cetaceans in the US from 199 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Commercial Fisheries
Commercial fishing is the activity of catching fish and other seafood for commercial profit, mostly from wild fisheries. It provides a large quantity of food to many countries around the world, but those who practice it as an industry must often pursue fish far into the ocean under adverse conditions. Large-scale commercial fishing is also known as industrial fishing. The major fishing industries are not only owned by major corporations but by small families as well. In order to adapt to declining fish populations and increased demand, many commercial fishing operations have reduced the sustainability of their harvest by fishing further down the food chain. This raises concern for fishery managers and researchers, who highlight how further they say that for those reasons, the sustainability of the marine ecosystems could be in danger of collapsing. Commercial fishermen harvest a wide variety of animals. However, a very small number of species support the majority of the world' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synchronous Spawning
''Reproductive synchrony'' is a term used in evolutionary biology and behavioral ecology. Reproductive synchrony—sometimes termed "ovulatory synchrony"—may manifest itself as "breeding seasonality". Where females undergo regular menstruation, " menstrual synchrony" is another possible term. Reproduction is said to be synchronised when fertile matings across a population are temporarily clustered, resulting in multiple conceptions (and consequent births) within a restricted time window. In marine and other aquatic contexts, the phenomenon may be referred to as mass spawning. Mass spawning has been observed and recorded in a large number of phyla, including in coral communities within the Great Barrier Reef. In primates, reproductive synchrony usually takes the form of conception and birth seasonality. The regulatory "clock", in this case, is the sun's position in relation to the tilt of the earth. In nocturnal or partly nocturnal primates—for example, owl monkeys—the per ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nototheniidae
: ''In some scientific literature, the term "cod icefish" is used to identify members of this family. This should not be confused with the term "icefish," which refers to the "white-blooded" fishes of the family Channichthyidae. See Icefish (other).'' Nototheniidae, the notothens or cod icefishes, is a family of ray-finned fishes, part of the suborder Notothenioidei which is traditionally placed within the order Perciformes. They are largely found in the Southern Ocean. Taxonomy Nototheniidae was described as a family in 1861 by the German-born British ichthyologist Albert Günther with the type genus being ''Notothenia'' which had been described in 1844 by Sir John Richardson with the species ''Notothenia coriiceps'' which Richardson had also described in 1844 subsequently being designated as the type in 1862 by Theodore Nicholas Gill. The name ''Notothenia'' means “coming from the south”, a reference to the Antarctic distribution of the genus. They are traditio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antarctic Krill
Antarctic krill (''Euphausia superba'') is a species of krill found in the Antarctic waters of the Southern Ocean. It is a small, swimming crustacean that lives in large schools, called swarms, sometimes reaching densities of 10,000–30,000 individual animals per cubic metre. It feeds directly on minute phytoplankton, thereby using the primary production energy that the phytoplankton originally derived from the sun in order to sustain their pelagic (open ocean) life cycle. It grows to a length of , weighs up to , and can live for up to six years. It is a key species in the Antarctic ecosystem and in terms of biomass, is one of the most abundant animal species on the planet (approximately 500 million tons, corresponding to 300 to 400 trillion individuals). Life cycle The main spawning season of Antarctic krill is from January to March, both above the continental shelf and also in the upper region of deep sea oceanic areas. In the typical way of all krill, the male attaches a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
