Mekong Freshwater Stingray
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Mekong Freshwater Stingray
The Mekong freshwater stingray, ''Hemitrygon laosensis'', is a species of stingray in the family Dasyatidae, restricted to the Mekong and Chao Phraya Rivers in Laos and Thailand; the occurrence in Chao Phraya is considered an introduction. Measuring up to across, this ray has an oval pectoral fin disc, a tail with both upper and lower fin folds, and a midline row of spine-like dermal denticles. A characteristic feature of this species is its bright orange underside. The Mekong freshwater stingray preys on invertebrates and is aplacental viviparous. It has been assessed as Endangered by the International Union for Conservation of Nature (IUCN), as it is threatened by overfishing and habitat degradation. Taxonomy and phylogeny The Mekong freshwater stingray was first recognized as a new species by Yasuhiko Taki, who included it as "''Dasyatis'' sp." in his 1968 list of Mekong River fishes from Laos. Taki's specimens were subsequently lost, and this ray was not formally described u ...
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Tyson R
Tyson is a male given name of old French origin meaning 'high-spirited', 'fire'. It is from this that a surname arose 'son of Tyson'. Surname * Alan Tyson (1926–2000), British musicologist *Barbara Tyson (born 1964), Canadian actress *Bill Tyson, Irish writer and producer *Cathy Tyson (born 1965), British actress *Charles Tyson (1885–1964), English footballer *Cicely Tyson (1924–2021), American actress *Donald J. Tyson (1930–2011), American business executive and billionaire *Edward Tyson (1650–1708), English scientist and physician *Frank Tyson (born 1930), English cricketer *Ian Tyson (born 1933), Canadian musician *Isaac Tyson (1792–1861), American mining industrialist *Jacob Tyson (1773–1848), American politician *James Tyson (1819–1898), Australian pastoralist *J. Anthony Tyson (born 1940), American physicist and astronomer * John M. Tyson (born 1953), American judge *June Tyson (1936–1992), American jazz singer *Keith Tyson (born 1969), British artist *Laur ...
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Overfishing
Overfishing is the removal of a species of fish (i.e. fishing) from a body of water at a rate greater than that the species can replenish its population naturally (i.e. the overexploitation of the fishery's existing fish stock), resulting in the species becoming increasingly underpopulated in that area. Overfishing can occur in water bodies of any sizes, such as ponds, wetlands, rivers, lakes or oceans, and can result in resource depletion, reduced biological growth rates and low biomass levels. Sustained overfishing can lead to critical depensation, where the fish population is no longer able to sustain itself. Some forms of overfishing, such as the overfishing of sharks, has led to the upset of entire marine ecosystems. Types of overfishing include: growth overfishing, recruitment overfishing, ecosystem overfishing. The ability of a fishery to recover from overfishing depends on whether its overall carrying capacity and the variety of ecological conditions are suitable for t ...
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Papilla (fish Mouth Structure)
The papilla, in certain kinds of fish, particularly rays, sharks, and catfish, are small lumps of dermal tissue found in the mouth, where they are "distributed uniformly on the tongue, palate, and pharynx".B. G. Kapoor, H. E. Evans, E. A. Pevzner "The gustatory system in fish" in ''Advances in Marine Biology, Volume 13'' (1976), F. S. Russell, Maurice Yonge (eds). They "project slightly above the surrounding multi-layered epithelium", and the taste buds of the fish are "situated along the crest or at the apex of the papillae". Unlike humans, fish have little or nothing in the way of a tongue The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ..., and those that have such an organ do not use it for tasting, but merely for cushioning the mouth and manipulating things within it. The papill ...
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Spiracle (vertebrates)
Spiracles () are openings on the surface of some animals, which usually lead to respiratory systems. The spiracle is a small hole behind each eye that opens to the mouth in some fish. In the jawless fish, the first gill opening immediately behind the mouth is essentially similar to the other gill opening. With the evolution of the jaw in the early jawed vertebrates, this gill slit was caught between the forward gill-rod (now functioning as the jaw) and the next rod, the hyomandibular bone, supporting the jaw hinge and anchoring the jaw to the skull proper. The gill opening was closed off from below, the remaining opening was small and hole-like, and is termed a spiracle. In many species of sharks and all rays the spiracle is responsible for the intake of water into the buccal space before being expelled from the gills. The spiracle is often located towards the top of the animal allowing breathing even while the animal is mostly buried under sediments. As sharks adapted a faster ...
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Chai Nat
Chai Nat ( th, ชัยนาท, ) is a town (''thesaban mueang'') in central Thailand, capital of Chai Nat province. It covers the whole ''tambon'' tambon Nai Mueang and parts of Ban Kluai, Tha Chai and Khao Tha Phra, all in Mueang Chai Nat district Mueang Chai Nat (, ) is the capital district (''amphoe mueang'') of Chai Nat province, central Thailand. Geography Neighbouring districts are (from the east clockwise) Sapphaya, Sankhaburi, Hankha, Wat Sing, and Manorom of Chai Nat province; .... As of 2006 it had a population of 14,469. The town is on the banks of the Chao Phraya River. The main road through the town is Phahonyothin Road (Highway 1). Bangkok lies 188 km to the south. References External links * *http://www.chainatcity.go.th (Thai) {{coord, 15, 11, 14, N, 100, 07, 42, E, type:city(14000)_region:TH, display=title Populated places in Chai Nat province Populated places on the Chao Phraya River Cities and towns in Thailand ...
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Habitat
In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as environment or vegetation assemblages, for which the term "habitat-type" is more appropriate. The physical factors may include (for example): soil, moisture, range of temperature, and light intensity. Biotic factors will include the availability of food and the presence or absence of predators. Every species has particular habitat requirements, with habitat generalist species able to thrive in a wide array of environmental conditions while habitat specialist species requiring a very limited set of factors to survive. The habitat of a species is not necessarily found in a geographical area, it can be the interior ...
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Freshwater
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. Fresh wa ...
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Gulf Of Thailand
The Gulf of Thailand, also known as the Gulf of Siam, is a shallow inlet in the southwestern South China Sea, bounded between the southwestern shores of the Indochinese Peninsula and the northern half of the Malay Peninsula. It is around in length and up to in width, and has a surface area of . The gulf is surrounded on the north, west and southwest by the coastlines of Thailand (hence the name), on the northeast by Cambodia and the Mekong Delta region of Vietnam, and opens to the South China Sea in the southeast. Names The modern Thai name of the gulf is ''Ao Thai'' ( th, อ่าวไทย, , 'Thai Gulf') and "Gulf of Thailand" has been adopted as the official name of the body by the International Hydrographic Organization. Its name in Malay is he "Gulf of Siam", ''Teluk Siam'', and in km, ឈូងសមុទ្រសៀម'', Chhoung Samut Siem''. In Thai, the gulf is historically known as ''Ao Sayam'' ( th, อ่าวสยาม). In Vietnamese it is known a ...
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Cytochrome B
Cytochrome b within both molecular and cell biology, is a protein found in the mitochondria of eukaryotic cells. It functions as part of the electron transport chain and is the main subunit of transmembrane cytochrome bc1 and b6f complexes. Function In the mitochondrion of eukaryotes and in aerobic prokaryotes, cytochrome b is a component of respiratory chain complex III () — also known as the bc1 complex or ubiquinol-cytochrome c reductase. In plant chloroplasts and cyanobacteria, there is an analogous protein, cytochrome b6, a component of the plastoquinone-plastocyanin reductase (), also known as the b6f complex. These complexes are involved in electron transport, the pumping of protons to create a proton-motive force ( PMF). This proton gradient is used for the generation of ATP. These complexes play a vital role in cells. Structure Cytochrome b/b6 is an integral membrane protein of approximately 400 amino acid residues that probably has 8 transmembrane segments. ...
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Phylogenetic
In biology, phylogenetics (; from Greek φυλή/ φῦλον [] "tribe, clan, race", and wikt:γενετικός, γενετικός [] "origin, source, birth") is the study of the evolutionary history and relationships among or within groups of organisms. These relationships are determined by Computational phylogenetics, phylogenetic inference methods that focus on observed heritable traits, such as DNA sequences, protein amino acid sequences, or morphology. The result of such an analysis is a phylogenetic tree—a diagram containing a hypothesis of relationships that reflects the evolutionary history of a group of organisms. The tips of a phylogenetic tree can be living taxa or fossils, and represent the "end" or the present time in an evolutionary lineage. A phylogenetic diagram can be rooted or unrooted. A rooted tree diagram indicates the hypothetical common ancestor of the tree. An unrooted tree diagram (a network) makes no assumption about the ancestral line, and does ...
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Type Specimen
In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set (mathematics), set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the ...
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