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Golden Cave Catfish
The cave catfish (''Clarias cavernicola'') is a critically endangered species of airbreathing catfish. Listed as Critically Endangered (CR B1+2c, E v2.3) This cavefish is only known to live in the Aigamas cave, Otjozondjupa region, Namibia. It has also been reported from the nearby Dragon's Breath Cave. The golden cave catfish lack pigmentation and are up to 16.1 cm (6.3 inches) in standard length. They have very small eyes that are covered with skin, and are probably effectively blind. They feed on detritus and invertebrates that fall into the lake in which they live. The population is estimated at 200–400 individuals. Little is known about its reproduction, and attempts to breed it in captivity have failed. The population is threatened by chance events and water extraction from the cave lake, which has resulted in a drop of the water level. It is the only known cavefish in mainland Southern Africa.Aldemaro, R., editor (2001). The Biology of Hypogean Fishes. Developme ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethelwynn Trewavas
Ethelwynn Trewavas (5 November 1900 – 16 August 1993) was an ichthyologist at the British Museum of Natural History. She was known for her work on the families Cichlidae and Sciaenidae. She worked with Charles Tate Regan, another ichthyologist and taxonomist. Academic studies and career She received her bachelor's degree and Board of Education Certificate in Teaching in 1921 from Reading University, and then worked as a teacher before being employed by the King's College of Household and Social Science as a part-time demonstrator, spending most of her time on research. She was taught by Dr. Nellie B. Eales when associated with the Freshwater Biological Association. She met Charles Regan and was employed by him as his assistant until hired by the British Museum (Natural History) as Assistant Keeper in 1935. She was appointed Deputy Keeper of Zoology in 1958, and retired in 1961. She served as the senior scientist in the Fish Section of the British Museum (Natural Histo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Detritus
In biology, detritus () is dead particulate organic material, as distinguished from dissolved organic material. Detritus typically includes the bodies or fragments of bodies of dead organisms, and fecal material. Detritus typically hosts communities of microorganisms that colonize and decompose (i.e. remineralize) it. In terrestrial ecosystems it is present as leaf litter and other organic matter that is intermixed with soil, which is denominated " soil organic matter". The detritus of aquatic ecosystems is organic material that is suspended in the water and accumulates in depositions on the floor of the body of water; when this floor is a seabed, such a deposition is denominated "marine snow". Theory The corpses of dead plants or animals, material derived from animal tissues (e.g. molted skin), and fecal matter gradually lose their form due to physical processes and the action of decomposers, including grazers, bacteria, and fungi. Decomposition, the process by which or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Of Africa
Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and 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 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 external armor that protected them from predators. The first fish with jaws appeared in the Silurian period, after which many (such as sharks) became formidable marine predators rather than just the prey of arthropods. Most f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cave Fish
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.Proud ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clarias
''Clarias'' is a genus of catfishes (order Siluriformes) of the family Clariidae, the airbreathing catfishes. The name is derived from the Greek ''chlaros'', which means lively, in reference to the ability of the fish to live for a long time out of water. Taxonomy ''Clarias'' has been found to be paraphyletic. A species of ''Heterobranchus'' (''H. longifilis'') clusters deeply inside the ''Clarias'' group. Distribution They are found in inland waters throughout much of the Old World, and are one of the most widespread catfish genera in the world. The genus is found in Southeast Asia and East Asia westwards through India and the Asia Minor to Africa. The diversity of these catfishes is highest in Africa. Some (notably the walking catfish) have become pest species where they have been accidentally introduced, and particularly in Cuba, where their introduction was intentional. Description ''Clarias'' species are recognized by their long-based dorsal and anal fins, which give them a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Fauna Of Namibia
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are Indigenous (ecology), indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example ''Cytisus, Cytisus aeolicus'' is an endemite of the Italian flora. ''Enidae, Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a Invasive species, non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caves Of Namibia
Namibia, a country in south-western Africa, has a total of 124 known caves, 41 of which are situated in the Otjozondjupa Region. In several of these caves research has been done and published in various journals, but of a variety of caves the location is not commonly known, as the information got lost over the years. Some locations are also deliberately kept secret to protect the caves. History The caves known to local people were reported by early explorers and travelers. The caves of Namibia are not reported for their beauty, but for their practical and curiosity reasons.NamibWeb (2012)History of caves in NamibiaRetrieved 31 July 2012 A very common belief is that caves were used as shelter places by the San people (Bushmen). However, San did not use caves to shelter in, as most caves of Namibia have vertical entrances and also are situated on top of elevations. Caves were only used when they were accessible and allowed observation over approaching and surrounding area and also r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Southern Africa
Southern Africa is the southernmost subregion of the African continent, south of the Congo and Tanzania. The physical location is the large part of Africa to the south of the extensive Congo River basin. Southern Africa is home to a number of river systems; the Zambezi River being the most prominent. The Zambezi flows from the northwest corner of Zambia and western Angola to the Indian Ocean on the coast of Mozambique. Along the way, the Zambezi River flows over the mighty Victoria Falls on the border between Zambia and Zimbabwe. Victoria Falls is one of the largest waterfalls in the world and a major tourist attraction for the region. Southern Africa includes both subtropical and temperate climates, with the Tropic of Capricorn running through the middle of the region, dividing it into its subtropical and temperate halves. Countries commonly included in Southern Africa include Angola, Botswana, the Comoros, Eswatini, Lesotho, Madagascar, Malawi, Mauritius, Mozambique, Namib ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blind Fish
A blind fish is a fish without functional eyes. Most blind fish species are found in dark habitats such as the deep ocean, deep river channels and underground. Blind fish species Agnathans *''Myxine glutinosa'' *''Myxine circifrons'' *'' Polistotrema stouti'' Cartilaginous fishes *Torpediniformes **''Benthobatis moresbyi'' **'' Typhlonarke aysoni'' **'' Typhlonarke tarakea'' Bony fishes *Anguilliformes **Moringuidae ***''Moringua abbreviata'' *Salmoniformes **Ipnopidae ***'' Ipnops murrayi'' ***'' Ipnops agassizi'' ***'' Ipnops meadi'' ***'' Bathymicrops regis'' ***'' Bathymicrops brevianalis'' ***'' Bathyphlops sewelli'' *Characiformes **Characidae ***'' Anoptichthys jordani'' ***'' Anoptichthys hubbsi'' ***'' Anoptichthys antrobius'' ***''Stygichthys typhlops'' *Cypriniformes **Cyprinidae ***''Caecobarbus geertsii'' ***'' Barbopsis devecchii'' ***''Iranocypris typhlops'' ***''Phreatichthys andruzzii'' ***'' Typhlogarra widdowsoni'' ***'' Puntius micr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Measurement
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 meas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dragon's Breath Cave
Dragon's Breath Cave was discovered by Roger Ellis during a caving expedition to the area in 1986. The cave is located northwest of Grootfontein in the Otjozondjupa Region of Namibia. It is named for the moist air rising from its entrance which resembled the breath of a Dragon. The cave contains the world's largest non- subglacial underground lake, with an area of almost . The lake is located around below the surface. Its total depth is . Although it has been reported that the rare fish species, '' Clarias cavernicola'', lives in the lake in the Dragon's Breath Cave, this is an error. It is only known from the nearby Aigamas Cave. Martyn Farr records in his book "The Darkness Beckons" the exploration of the cave by a team of divers and cavers lead by Roger Ellis and Charles Maxwell of the South African Spelaeological Association a year after the cave was identified in 1986 by cavers as being of significant size. See also * * , a project based on another fossil water Fossi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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