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Sternarchorhynchus
''Sternarchorhynchus'' is a genus of ghost knifefishes with a long, decurved snout that are found in river basins in tropical South America. Distribution, habitat and conservation Of the 32 recognized species, more than are restricted to the Amazon basin (including the Tocantins system) in Bolivia, Brazil, Colombia, Ecuador and Peru, 7 species are found in river basins flowing into the Gulf of Paria in Colombia and Venezuela (mostly Orinoco system, but ''S. mendesi'' in Guanipa and San Juan), ''S. freemani'' is from the Essequibo basin in Guyana, ''S. galibi'' is from the Maroni basin in French Guiana and Suriname, and ''S. britskii'' is from the upper Paraná basin in Brazil.de Santana, C. D. and R.P. Vari (2010). Electric fishes of the genus Sternarchorhynchus (Teleostei, Ostariophysi, Gymnotiformes); phylogenetic and revisionary studies. Zool. J. Linn. Soc. 159: 223-371. There are records of ''Sternarchorhynchus'' from the Oyapock on the French Guiana–Brazil border, bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sternarchorhynchus Retzeri
''Sternarchorhynchus'' is a genus of ghost knifefishes with a long, decurved snout that are found in river basins in tropical South America. Distribution, habitat and conservation Of the 32 recognized species, more than are restricted to the Amazon basin (including the Tocantins system) in Bolivia, Brazil, Colombia, Ecuador and Peru, 7 species are found in river basins flowing into the Gulf of Paria in Colombia and Venezuela (mostly Orinoco system, but ''S. mendesi'' in Guanipa and San Juan), ''S. freemani'' is from the Essequibo basin in Guyana, ''S. galibi'' is from the Maroni basin in French Guiana and Suriname, and ''S. britskii'' is from the upper Paraná basin in Brazil.de Santana, C. D. and R.P. Vari (2010). Electric fishes of the genus Sternarchorhynchus (Teleostei, Ostariophysi, Gymnotiformes); phylogenetic and revisionary studies. Zool. J. Linn. Soc. 159: 223-371. There are records of ''Sternarchorhynchus'' from the Oyapock on the French Guiana–Brazil border, but t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Apteronotidae
The ghost knifefishes are a family, Apteronotidae, of ray-finned fishes in the order Gymnotiformes. These fish are native to Panama and South America. They inhabit a wide range of freshwater habitats, but more than half the species in the family are found deep in rivers (typically deeper than ) where there is little or no light. The Apteronotidae should not be confused with the unrelated Notopteridae, which are also commonly called knifefishes. They are distinguished from other gymnotiform fishes by the presence of a caudal fin (all other families lack a caudal fin) as well as a fleshy dorsal organ represented by a longitudinal strip along the dorsal midline. They vary greatly in size, ranging from about in total length in the smallest species to in the largest. It has been claimed that '' Apteronotus magdalenensis'' is up to , but this is not supported by recent studies, which indicate that it does not surpass about . These nocturnal fish have small eyes. Also, sexual dimorph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eigenmannia Vicentespelaea
''Eigenmannia vicentespelaea'' is a species of electric fish, weakly electric Gymnotiformes, knifefish in the family (biology), family Sternopygidae. Native to the São Domingos, Goiás, São Domingos karst area in central Brazil, it is the only known knifefish to exclusively Cavefish, inhabit caves. Measuring up to long, ''E. vicentespelaea'' can be distinguished from its relatives by its translucent body and reduced or absent eyes. As some individuals retain well-developed eyes, this fish may have colonized caves only recently in evolutionary time. Taxonomy Brazilian ichthyologist Mauro Luís Triques described ''E. vicentespelaea'' in a 1996 volume of the scientific journal ''Revue Française de Aquariologie'', from two specimens caught in 1978. He chose the specific name (zoology), specific epithet ''vicentespelaea'' from the São Vicente I cave, the type species, type locality, and ''speleum'', Latin for "cave". Based on color pattern and morphology (biology), morphology, it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnotiformes
The Gymnotiformes are an order of teleost bony fishes commonly known as Neotropical knifefish or South American knifefish. They have long bodies and swim using undulations of their elongated anal fin. Found almost exclusively in fresh water (the only exceptions are species that occasionally may visit brackish water to feed), these mostly nocturnal fish are capable of producing electric fields to detect prey, for navigation, communication, and, in the case of the electric eel (''Electrophorus electricus''), attack and defense. A few species are familiar to the aquarium trade, such as the black ghost knifefish (''Apteronotus albifrons''), the glass knifefish (''Eigenmannia virescens''), and the banded knifefish (''Gymnotus carapo''). Description Anatomy and locomotion Aside from the electric eel (''Electrophorus electricus''), Gymnotiformes are slender fish with narrow bodies and tapering tails, hence the common name of "knifefishes". They have neither pelvic fins nor do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xingu River
The Xingu River ( ; pt, Rio Xingu, ; Mẽbêngôkre: ''Byti'', ) is a river in north Brazil. It is a southeast tributary of the Amazon River and one of the largest clearwater rivers in the Amazon basin, accounting for about 5% of its water. __TOC__ Description and history The first Indigenous Park in Brazil was created in the river basin by the Brazilian government in the early 1960s. This park marks the first indigenous territory recognized by the Brazilian government and it was the world's largest indigenous preserve on the date of its creation. Currently, fourteen tribes live within Xingu Indigenous Park, surviving on natural resources and extracting from the river most of what they need for food and water. The Brazilian government is building the Belo Monte Dam, which will be the world's third-largest hydroelectric dam, on the Lower Xingu. Construction of this dam is under legal challenge by environment and indigenous groups, who assert the dam would have negative envi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazon River
The Amazon River (, ; es, Río Amazonas, pt, Rio Amazonas) in South America is the largest river by discharge volume of water in the world, and the disputed longest river system in the world in comparison to the Nile. The headwaters of the Apurímac River on Nevado Mismi had been considered for nearly a century as the Amazon basin's most distant source, until a 2014 study found it to be the headwaters of the Mantaro River on the Cordillera Rumi Cruz in Peru. The Mantaro and Apurímac rivers join, and with other tributaries form the Ucayali River, which in turn meets the Marañón River upstream of Iquitos, Peru, forming what countries other than Brazil consider to be the main stem of the Amazon. Brazilians call this section the Solimões River above its confluence with the Rio Negro forming what Brazilians call the Amazon at the Meeting of Waters ( pt, Encontro das Águas) at Manaus, the largest city on the river. The Amazon River has an average discharge of abo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blackwater River
A blackwater river is a type of river with a slow-moving channel flowing through forested swamps or wetlands. As vegetation decays, tannins leach into the water, making a transparent, acidic water that is darkly stained, resembling black tea. Most major blackwater rivers are in the Amazon Basin and the Southern United States. The term is used in fluvial studies, geology, geography, ecology, and biology. Not all dark rivers are blackwater in that technical sense. Some rivers in temperate regions, which drain or flow through areas of dark black loam, are simply black due to the color of the soil; these rivers are ''black mud rivers''. There are also black mud estuaries. Blackwater rivers are lower in nutrients than whitewater rivers and have ionic concentrations higher than rainwater. The unique conditions lead to flora and fauna that differ from both whitewater and clearwater rivers. The classification of Amazonian rivers into black, clear, and whitewater was first propose ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tefé River
The Tefé River (Teffé River in early accounts; pt, Rio Tefé) is a tributary of the Amazon River ( Solimões section) in Amazonas state in north-western Brazil. The Tefé River flows through the Juruá-Purus moist forests ecoregion. It forms the eastern boundary of the Tefé National Forest, created in 1989. Immediately before merging into the Amazon, it forms Lake Tefé ( pt, Lago Tefé). The city of Tefé is located on the banks of the lake. The Tefé River is a blackwater river A blackwater river is a type of river with a slow-moving channel flowing through forested swamps or wetlands. As vegetation decays, tannins leach into the water, making a transparent, acidic water that is darkly stained, resembling black tea. .... See also * List of rivers of Amazonas References Brazilian Ministry of Transport Rivers of Amazonas (Brazilian state) Tributaries of the Amazon River Tefé {{AmazonasBR-river-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clearwater River (river Type)
A clearwater river is classified based on its chemistry, sediments and water colour. Clearwater rivers have a low conductivity, relatively low levels of dissolved solids, typically have a neutral to slightly acidic pH and are very clear with a greenish colour. Clearwater rivers often have fast-flowing sections. The main clearwater rivers are South American and have their source in the Brazilian Plateau or the Guiana Shield. Outside South America the classification is not commonly used, but rivers with clearwater characteristics are found elsewhere. Amazonian rivers fall into three main categories: clearwater, blackwater and whitewater. This classification system was first proposed by Alfred Russel Wallace in 1853 based on water colour, but the types were more clearly defined according to chemistry and physics by from the 1950s to the 1980s. Although many Amazonian rivers fall clearly into one of these categories, others show a mix of characteristics and may vary depending ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Várzea Forest
A várzea forest is a seasonal floodplain forest inundated by whitewater rivers that occurs in the Amazon biome. Until the late 1970s, the definition was less clear and várzea was often used for all periodically flooded Amazonian forests. Although sometimes described as consisting only of forest, várzea also contains more open, seasonally flooded habitats such as grasslands, including floating meadows. Description Along the Amazon River and many of its tributaries, high annual rainfall that occurs mostly within a rainy season results in extensive seasonal flooding of areas from stream and river discharge. The result is a rise in water level, with nutrient rich waters. The Iquitos várzea ecoregion covers the margins of the upper Amazon and its tributaries. Further down are the Purus várzea in the middle Amazon, the Monte Alegre várzea and Gurupa várzea on the lower Amazon and the Marajó várzea at the mouth of the Amazon. The Marajó várzea is affected by both fresh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cavefish
Cavefish or cave fish is a generic term for fresh and brackish water fish adapted to life in caves and other underground habitats. Related terms are subterranean fish, troglomorphic fish, troglobitic fish, stygobitic fish, phreatic fish and hypogean fish.Romero, Aldemaro, editor (2001). ''The Biology of Hypogean Fishes.'' Developments in Environmental Biology of Fishes. Helfman, G.S. (2007). ''Fish Conservation: A Guide to Understanding and Restoring Global Aquatic Biodiversity and Fishery Resources'', pp. 41–42. Island Press. There are more than 200 scientifically described species of obligate cavefish found on all continents, except Antarctica. Although widespread as a group, many cavefish species have very small ranges and are seriously threatened.Fenolio, D.B.; Zhao, Y.; Niemiller, M.L.; and Stout, J. (2013). ''In-situ observations of seven enigmatic cave loaches and one cave barbel from Guangxi, China, with notes on conservation status.'' Speleobiology Notes 5: 19-33. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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