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Gymnocypris Przewalskii
''Gymnocypris przewalskii'' (common name: Przewalskii's naked carp; in ) is a species of cyprinid that is endemic to the Lake Qinghai basin in China, where it is the dominant fish species (the other natives are four ''Triplophysa'' loaches).Zhang, Ludwig, Zhang, Tong, Li, Tang, Peng & Zhao (2015). Gymnocypris przewalskii (Cyprinidae) on the Tibetan Plateau'. Scientific Reports 5, Article 9780. ''G. przewalskii'' is a planktivore with a main population that migrates from the lake to rivers to spawn and another that lives its entire life in the nearby Ganzi River. The species is listed as endangered on the China Species Red List due to overfishing and habitat loss, which has led to suspension of its commercial fishery four times since 1989. Named in honor of geographer and explorer Nikolai Przhevalsky (also spelled Przewalski and Prjevalsky, 1839-1888), who collected the type species and in whose book about Mongolia Kessler’s description appeared. Characteristics Naked carp ...
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Karl Kessler
Karl Fedorovich Kessler (19 November 1815 – 3 March 1881) was a German-Russian zoologist and author of zoological taxa signed ''Kessler'', who was mostly active in Kyiv, Ukraine. He conducted most of his studies of birds in Ukrainian regions of the Russian Empire: Kiev Governorate, Volyn Governorate, Kherson Governorate, Poltava Governorate and Bessarabia. He also studied the fish of the Dniester, Dnieper, and Southern Bug rivers, and on the Ukrainian coast of the Black Sea. Kessler was one of the first zoologists to propose that mutual aid, rather than mutual struggle, was the main factor in the evolution of a species. The anarchist Peter Kropotkin later developed this theory in his book '' Mutual Aid: A Factor of Evolution''. Tribute The Kessler's gudgeon ''(Romanogobio kesslerii)'' was named after him. See also * :Taxa named by Karl Kessler *Antoine Laurent Apollinaire Fée *Jean-Charles Houzeau *Alphonse Toussenel Alphonse Toussenel (March 17, 1803 – April 30, 18 ...
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Brackish
Brackish water, sometimes termed brack water, is water occurring in a natural environment that has more salinity than freshwater, but not as much as seawater. It may result from mixing seawater (salt water) and fresh water together, as in estuaries, or it may occur in brackish fossil aquifers. The word comes from the Middle Dutch root '' brak''. Certain human activities can produce brackish water, in particular civil engineering projects such as dikes and the flooding of coastal marshland to produce brackish water pools for freshwater prawn farming. Brackish water is also the primary waste product of the salinity gradient power process. Because brackish water is hostile to the growth of most terrestrial plant species, without appropriate management it is damaging to the environment (see article on shrimp farms). Technically, brackish water contains between 0.5 and 30 grams of salt per litre—more often expressed as 0.5 to 30 parts per thousand (‰), which is a specific grav ...
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Freshwater Fish Of China
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non- salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/ sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of higher plants and most insects, amphibians, reptiles, mammals and birds need fresh water to survive. ...
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Taxa Named By Karl Kessler
In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular name and given a particular ranking, especially if and when it is accepted or becomes established. It is very common, however, for taxonomists to remain at odds over what belongs to a taxon and the criteria used for inclusion. If a taxon is given a formal scientific name, its use is then governed by one of the nomenclature codes specifying which scientific name is correct for a particular grouping. Initial attempts at classifying and ordering organisms (plants and animals) were set forth in Carl Linnaeus's system in '' Systema Naturae'', 10th edition (1758), as well as an unpublished work by Bernard and Antoine Laurent de Jussieu. The idea of a unit-based system of biological classification was first made widely available in 1805 in the i ...
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Gymnocypris
''Gymnocypris'' is a genus of fish in the family Cyprinidae endemic to China. Species There are currently 10 recognized species in this genus: * ''Gymnocypris chilianensis'' S. C. Li & S. Y. Chang, 1974 * ''Gymnocypris chui'' T. L. Tchang, T. H. Yueh & H. C. Hwang, 1964 * ''Gymnocypris dobula'' Günther, 1868 * ''Gymnocypris eckloni'' Herzenstein, 1891 * ''Gymnocypris namensis'' ( Y. F. Wu & M. L. Ren, 1982) * ''Gymnocypris pengquensis'' Y. T. Tang, C. G. Feng, K. Y. Wanghe, G. G. Li & K. Zhao, 2016 Tang, Y.-T., Feng, C.-G., Wanghe, K.-Y., Li, G.-G. & Zhao, K. (2016): Taxonomic status of a population of ''Gymnocypris waddelli'' Regan, 1905 (Cypriniformes: Schizothoracinae) distributed in Pengqu River, Tibet, China. ''Zootaxa, 4126 (1): 123–137.'' * ''Gymnocypris potanini'' Herzenstein, 1891 * ''Gymnocypris przewalskii'' (Kessler, 1876) * ''Gymnocypris scleracanthus'' Tsao, C. Z. Wu, Chen & Zhu, 1992 * ''Gymnocypris waddellii'' Regan The family name Regan, alon ...
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Gill Raker
Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch (gill arch) and are involved with suspension feeding tiny prey. They are not to be confused with the gill filaments that compose the fleshy part of the gill used for gas exchange. Rakers are usually present in two rows, projecting from both the anterior and posterior side of each gill arch. Rakers are widely varied in number, spacing, and form. By preventing food particles from exiting the spaces between the gill arches, they enable the retention of food particles in filter feeders. The structure and spacing of gill rakers in fish determines the size of food particles trapped, and correlates with feeding behavior. Fish with densely spaced, elongated, comb-like gill rakers are efficient at filtering tiny prey, whereas carnivores and omnivores often have more widely spaced gill rakers with secondary projections. Because gill raker characters often vary between closely related taxa, they are ...
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Subspecies
In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species have subspecies, but for those that do there must be at least two. Subspecies is abbreviated subsp. or ssp. and the singular and plural forms are the same ("the subspecies is" or "the subspecies are"). In zoology, under the International Code of Zoological Nomenclature, the subspecies is the only taxonomic rank below that of species that can receive a name. In botany and mycology, under the International Code of Nomenclature for algae, fungi, and plants, other infraspecific ranks, such as variety, may be named. In bacteriology and virology, under standard bacterial nomenclature and virus nomenclature, there are recommendations but not strict requirements for recognizing other important infraspecific ranks. A taxonomist decides whether ...
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Ecotype
In evolutionary ecology, an ecotype,Greek: ''οίκος'' = home and ''τύπος'' = type, coined by Göte Turesson in 1922 sometimes called ecospecies, describes a genetically distinct geographic variety, population, or race within a species, which is genotypically adapted to specific environmental conditions. Typically, though ecotypes exhibit phenotypic differences (such as in morphology or physiology) stemming from environmental heterogeneity, they are capable of interbreeding with other geographically adjacent ecotypes without loss of fertility or vigor. ''Ecology: From individuals to ecosystems'' by Begon, Townsend, Harper, Blackwell Publishing 4th ed. (2006), p.5,6,7,8''Environmental Encyclopedia'' by Bortman, Brimblecombe, Mary Ann Cunningham, William P. Cunningham, Freedman - 3rd ed., p.435, "Ecotype" Definition An ecotype is a variant in which the phenotypic differences are too few or too subtle to warrant being classified as a subspecies. These different variants ca ...
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Osmoregulatory
Osmoregulation is the active regulation of the osmotic pressure of an organism's body fluids, detected by osmoreceptors, to maintain the homeostasis of the organism's water content; that is, it maintains the fluid balance and the concentration of electrolytes (salts in solution which in this case is represented by body fluid) to keep the body fluids from becoming too diluted or concentrated. Osmotic pressure is a measure of the tendency of water to move into one solution from another by osmosis. The higher the osmotic pressure of a solution, the more water tends to move into it. Pressure must be exerted on the hypertonic side of a selectively permeable membrane to prevent diffusion of water by osmosis from the side containing pure water. Although there may be hourly and daily variations in osmotic balance, an animal is generally in an osmotic steady state over the long term. Organisms in aquatic and terrestrial environments must maintain the right concentration of solutes and am ...
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Oxygen Consumption
Oxygen is the chemical element with the symbol O and atomic number 8. It is a member of the chalcogen group in the periodic table, a highly reactive nonmetal, and an oxidizing agent that readily forms oxides with most elements as well as with other compounds. Oxygen is Earth's most abundant element, and after hydrogen and helium, it is the third-most abundant element in the universe. At standard temperature and pressure, two atoms of the element bind to form dioxygen, a colorless and odorless diatomic gas with the formula . Diatomic oxygen gas currently constitutes 20.95% of the Earth's atmosphere, though this has changed considerably over long periods of time. Oxygen makes up almost half of the Earth's crust in the form of oxides.Atkins, P.; Jones, L.; Laverman, L. (2016).''Chemical Principles'', 7th edition. Freeman. Many major classes of organic molecules in living organisms contain oxygen atoms, such as proteins, nucleic acids, carbohydrates, and fats, as do the ...
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Metabolic Rate
Metabolism (, from el, μεταβολή ''metabolē'', "change") is the set of life-sustaining chemical reactions in organisms. The three main functions of metabolism are: the conversion of the energy in food to energy available to run cellular processes; the conversion of food to building blocks for proteins, lipids, nucleic acids, and some carbohydrates; and the elimination of metabolic wastes. These enzyme-catalyzed reactions allow organisms to grow and reproduce, maintain their structures, and respond to their environments. The word metabolism can also refer to the sum of all chemical reactions that occur in living organisms, including digestion and the transportation of substances into and between different cells, in which case the above described set of reactions within the cells is called intermediary (or intermediate) metabolism. Metabolic reactions may be categorized as ''catabolic'' – the ''breaking down'' of compounds (for example, of glucose to pyruvate by cel ...
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Urine
Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excretion, excreted from the body through the urethra. Cell (biology), Cellular metabolism generates many by-products that are rich in nitrogen and must be clearance (medicine), cleared from the Circulatory system, bloodstream, such as urea, uric acid, and creatinine. These by-products are expelled from the body during urination, which is the primary method for excreting water-soluble chemicals from the body. A urinalysis can detect nitrogenous wastes of the mammalian body. Urine plays an important role in the earth's nitrogen cycle. In balanced ecosystems, urine fertilizes the soil and thus helps plants to grow. Therefore, Reuse of excreta, urine can be used as a fertilizer. Some animals use it to territory (animal)#Scent marking, mark their territories. Historically, aged or fermented urine (kn ...
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