Freshwater Whipray
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Freshwater Whipray
The freshwater whipray (''Urogymnus dalyensis'') is a little-known species of stingray in the family Dasyatidae, found in a number of large rivers and associated estuaries in northern Australia. Until recently, this species was regarded as a regional subpopulation of the similar-looking but much larger giant freshwater stingray (''U. polylepsis'') of Southeast Asia. Typically reaching across, the freshwater whipray has a distinctively shaped, rounded pectoral fin disc, a projecting snout, and a thin tail without fin folds. It is plain brown above and white below with dark marginal bands. It may occasionally travel onto land and can "breathe" out of water for up to 7 minutes. The freshwater whipray is an active hunter of small fishes and shrimps, and does not currently face substantial conservation threats. Taxonomy The first known specimen of the freshwater whipray was caught during a 1989 scientific expedition from the Daly River, after which it would eventually be named. Vari ...
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Peter R
Peter may refer to: People * List of people named Peter, a list of people and fictional characters with the given name * Peter (given name) ** Saint Peter (died 60s), apostle of Jesus, leader of the early Christian Church * Peter (surname), a surname (including a list of people with the name) Culture * Peter (actor) (born 1952), stage name Shinnosuke Ikehata, Japanese dancer and actor * ''Peter'' (album), a 1993 EP by Canadian band Eric's Trip * ''Peter'' (1934 film), a 1934 film directed by Henry Koster * ''Peter'' (2021 film), Marathi language film * "Peter" (''Fringe'' episode), an episode of the television series ''Fringe'' * ''Peter'' (novel), a 1908 book by Francis Hopkinson Smith * "Peter" (short story), an 1892 short story by Willa Cather Animals * Peter, the Lord's cat, cat at Lord's Cricket Ground in London * Peter (chief mouser), Chief Mouser between 1929 and 1946 * Peter II (cat), Chief Mouser between 1946 and 1947 * Peter III (cat), Chief Mouser between 1947 ...
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Molecular Phylogenetic
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical framew ...
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Wenlock River
The Wenlock River is a river located on the Cape York Peninsula in Far North Queensland, Australia. Course and features The river rises on the western slopes of the Great Dividing Range below Jacks Knob, west of Nundah homestead. The river flows generally north-west through tropical savanna plains and wetlands, joined by fifteen minor tributaries, before reaching its mouth and joining with the Ducie River on the western side of the peninsula at Port Musgrave, just north of Mapoon. Finally, the Wenlock River enters the Gulf of Carpentaria and descends over its course. The total catchment size is . The river has no water storage facilities built on it and there is little development within the drainage basin, resulting in a low population. In 2010, the Queensland Government declared the river a 'wild river', one of thirteen Queensland rivers that are free of dams, weirs, irrigation schemes and industrial development, and remain largely intact. Much of the river is border ...
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South Alligator River
Alligator Rivers is the name of an area in an Arnhem Land region of the Northern Territory of Australia, containing three rivers, the East, West, and South Alligator Rivers. It is regarded as one of the richest biological regions in Australia, with part of the region in the Kakadu National Park. It is an Important Bird Area (IBA), lying to the east of the Adelaide and Mary River Floodplains IBA. It also contains mineral deposits, especially uranium, and the Ranger Uranium Mine is located there. The area is also rich in Australian Aboriginal art, with 1500 sites. The Kakadu National Park is one of the few World Heritage sites on the list because of both its natural and human heritage values. They were explored by Lieutenant Phillip Parker King in 1820, who named them in the mistaken belief that the crocodiles in the estuaries were alligators. Rivers The East Alligator River is about long. After rising in the northern part of the Arnhem Land Plateau, it flows with tributa ...
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Roper River
The Roper River is a large perennial river located in the Katherine region of the Northern Territory of Australia. Location and features Formed by the confluence of the Waterhouse River and Roper Creek, the Roper River rises east of Mataranka in the Elsey National Park and flows generally east for over to meet the sea in Limmen Bight on the Gulf of Carpentaria. The river is joined by fifteen tributaries including the Chambers, Strangways, Jalboi, Hodgson and the Wilton Rivers. The river descends over its course and has a catchment area of , which is one of the largest river catchment areas in the Northern Territory. The Roper River is navigable for about , until the tidal limit at Roper Bar, and forms the southern boundary of the region known as Arnhem Land. Mataranka Hot Springs and the township of Mataranka lie close to the river at its western end. Port Roper lies near its mouth on Limmen Bight. The river has a mean annual outflow of . Etymology The first European to ...
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Ord River
The Ord River is a river in the Kimberley region of Western Australia. The river's catchment covers . The lower Ord River and the conjunction with Cambridge Gulf create the most northern estuarine environment in Western Australia. The Ord River Irrigation Scheme was built in stages during the 20th century. Australia's largest artificial lake by volume, Lake Argyle, was completed in 1972. It has not been economically successful; $1.45 billion has been spent on the Ord Irrigation Scheme for a return of 17 cents on the dollar, and only 260 jobs created. The lower reaches of the river support an important wetland area known as the Ord River Floodplain, a protected area that contains numerous mangrove forests, lagoons, creeks, flats and extensive floodplains. The traditional owners are the Miriwoong and Gajerrong peoples who have inhabited the area for thousands of years and know the Ord River as . In a letter to the Surveyor General, dated 12 October 1959, Louise Gardine ...
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Normanby River
The Normanby River, comprising the East Normanby River, the West Normanby River, the East Normanby River North Branch, the East Normanby River South Branch and the Granite Normanby River, is a river system located in Far North Queensland, Australia. Location and features With its headwaters in the Great Dividing Range west of in the Wet Tropics of Queensland, the Normanby River is formed by the confluence of the East and West Branches of the river at an elevation of . The river flows generally north-northwestw through seasonally flooded savanna grassland to reach its mouth in Princess Charlotte Bay about northwest of . The river is joined by 18 tributaries including the Laura River. The river flows through the Rinyirru National Park, which covers as much as a fifth of the river's basin and is completely impassable during the wet season between November and May. The Rinyirru National Park consists of large wetlands which possess a high diversity of fish species. Near i ...
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Mitchell River (Queensland)
The Mitchell River is a river located in Far North Queensland, Australia. The river rises on the Atherton Tableland about northwest of Cairns and flows about northwest across Cape York Peninsula from Mareeba to the Gulf of Carpentaria. The river's watershed covers an area of . The Mitchell River has the state's largest discharge, at annually, but is intermittent and may be dry for part of the year. Lake Mitchell is the main water storage facility on the river. It was named by Ludwig Leichhardt on the 16 June 1845 after Sir Thomas Mitchell while he was on his overland expedition from Moreton Bay to Port Essington. It may have been previously named the Vereenighde River in 1623 by a Dutch merchant and navigator, Jan Carstensz. Biophysical aspects The Mitchell River and its tributaries have for a long time carved their way westwards through the rugged, weathered highlands of the Great Dividing Range, carrying away sediments to be deposited in the broad floodplains and w ...
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Gilbert-Einasleigh River
The Gilbert River is located in Far North Queensland, Australia. When combined with the Einasleigh River, the river system is the largest river system in northern Australia. Features and location The Gilbert River rises below Conical Hill in the Einasleigh Uplands, draining the eastern slopes of the Gregory Range and the western slopes of the Newcastle Range, north of . The river flows generally northwest, joined by forty tributaries that drain the Blackbraes National Park including, from source to mouth, the Styx, Percy, Robertson, Langdon, Little, and Einasleigh rivers and numerous creeks. North of the Gilbert discharges into the Gulf of Carpentaria. However, northwest of an anabranch of the river forms confluence with the Smithburne River, also emptying into the Gulf. The Gilbert River has a catchment area of of which , or a third of the total catchment, is a vast estuarine delta approximately wide that largely consists of tidal flats and mangrove swamps across the G ...
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Fitzroy River (Western Australia)
The Fitzroy River is located in the West Kimberley region of Western Australia. It has 20 tributaries and its catchment occupies an area of , within the Canning Basin and the Timor Sea drainage division. It often floods extensively during the wet season, and is known as the major remaining habitat for the critically endangered sawfish. History Pre-colonisation The first people to live along the river were the traditional owners of the areas around the river, including the Bunuba and Nyikina people to the west, and the Walmajarri and Gooniyandi people to the east, who have lived in the area for at least 40,000 years. The Nyikina and Bunuba people know the river as ''Mardoowarra'' and Bandaral Ngarri respectively; the river and its vast floodplains are of great spiritual, cultural, medicinal and ecological significance. The Nyikina word ''Raparapa'', translates as "alongside the river". 19th to 21st centuries The first European to visit the Fitzroy River was George Grey in 1 ...
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Brackish Water
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 gr ...
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Fresh Water
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 ...
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