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Coptodon Bemini
''Coptodon bemini'' is a critically endangered species of fish in the cichlid family. It is endemic to Lake Bermin in Cameroon. It is threatened by pollution and sedimentation from human activities, and potentially also by large emissions of carbon dioxide (CO2) from the lake's bottom (compare Lake Nyos Lake Nyos ( ) is a crater lake in the Region of Cameroon, located about northwest of Yaoundé, the capital. Nyos is a deep lake high on the flank of an inactive volcano in the Oku volcanic plain along the Cameroon line of volcanic activity ...), although Bermin is too shallow to contain very high amounts of this gas.Freeth, S.J.; C.O. Ofoegbu; and K.M. Onuoha (1992). Natural Hazards in West and Central Africa, pp. 50—51. References bemini Fish of Cameroon Endemic fauna of Cameroon Lake fish of Africa Fish described in 1972 Taxonomy articles created by Polbot Taxobox binomials not recognized by IUCN {{Cichlidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dirk Frans Elisabeth Thys Van Den Audenaerde
A dirk is a long bladed thrusting dagger.Chisholm, Hugh (ed.), ''Dagger'', The Encyclopædia Britannica, 11th ed., Vol. VII, New York, NY: Cambridge University Press (1910), p. 729 Historically, it gained its name from the Highland Dirk (Scots Gaelic "Dearg") where it was a personal weapon of officers engaged in naval hand-to-hand combat during the Age of SailO'Brian, Patrick, ''Men-of-War: Life In Nelson's Navy'', New York: W.W. Norton & Co., (1974), p. 35 as well as the personal sidearm of Highlanders. It was also the traditional sidearm of the Highland Clansman and later used by the officers, pipers, and drummers of Scottish Highland regiments around 1725 to 1800 and by Japanese naval officers. Etymology The term is associated with Scotland in the Early Modern Era, being attested from about 1600. The term was spelled ''dork'' or ''dirk'' during the 17th century,Head, T.F. ''The Concise Oxford Dictionary of English Etymology'' Oxford University Press (1996) presumed relat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cichlid
Cichlids are fish from the family Cichlidae in the order Cichliformes. Cichlids were traditionally classed in a suborder, the Labroidei, along with the wrasses ( Labridae), in the order Perciformes, but molecular studies have contradicted this grouping. The closest living relative of cichlids is probably the convict blenny, and both families are classified in the 5th edition of ''Fishes of the World'' as the two families in the Cichliformes, part of the subseries Ovalentaria. This family is both large and diverse. At least 1,650 species have been scientifically described, making it one of the largest vertebrate families. New species are discovered annually, and many species remain undescribed. The actual number of species is therefore unknown, with estimates varying between 2,000 and 3,000. Many cichlids, particularly tilapia, are important food fishes, while others, such as the ''Cichla'' species, are valued game fish. The family also includes many popular freshwater aquariu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
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 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 aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a 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 species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Bermin
Lake Bermin (sometimes spelled Bemin or Beme) is a small lake in the volcanic chain in the Southwest Region of Cameroon. It is a volcanic lake with a diameter of about Martin; Cutler; Friel; Touokong; Coop; and Wainwright (2015). Complex histories of repeated gene flow in Cameroon crater lake cichlids cast doubt on one of the clearest examples of sympatric speciation. Evolution 69-6: 1406–1422. and a crater rim that rises to a height of about .Dickinson, C. (2005). The Tilapia of Lake Bernin, Cameroon.'' Modern Aquarium -Greater City A.S. (NY): 15–16 This highly isolated lake is roughly circular in shape, lacks an inflow, but has an outflow into the Cross River system.Schliewen, U.K., Tautz, D., and Pääbo, S. (1994). ''Sympatric speciation suggested by monophyly of crater lake cichlids.'' Nature 368(6472): 629–632. Biology Despite its very small size, it supports nine endemic species of coptodonine cichlid fishes ('' C. bakossiorum'', '' C. bemini'', '' C. bythobates'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cameroon
Cameroon (; french: Cameroun, ff, Kamerun), officially the Republic of Cameroon (french: République du Cameroun, links=no), is a country in west-central Africa. It is bordered by Nigeria to the west and north; Chad to the northeast; the Central African Republic to the east; and Equatorial Guinea, Gabon and the Republic of the Congo to the south. Its coastline lies on the Bight of Biafra, part of the Gulf of Guinea and the Atlantic Ocean. Due to its strategic position at the crossroads between West Africa and Central Africa, it has been categorized as being in both camps. Its nearly 27 million people speak 250 native languages. Early inhabitants of the territory included the Sao civilisation around Lake Chad, and the Baka hunter-gatherers in the southeastern rainforest. Portuguese explorers reached the coast in the 15th century and named the area ''Rio dos Camarões'' (''Shrimp River''), which became ''Cameroon'' in English. Fulani soldiers founded the Adamawa Emirate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollution
Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the components of pollution, can be either foreign substances/energies or naturally occurring contaminants. Although environmental pollution can be caused by natural events, the word pollution generally implies that the contaminants have an anthropogenic source – that is, a source created by human activities. Pollution is often classed as point source or nonpoint source pollution. In 2015, pollution killed nine million people worldwide (one in six deaths). This remained unchanged in 2019, with little real progress against pollution being identifiable. Air pollution accounted for of these earlier deaths. Major forms of pollution include air pollution, light pollution, litter, noise pollution, plastic pollution, soil contamination, radioactiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Siltation
Siltation, is water pollution caused by particulate terrestrial clastic material, with a particle size dominated by silt or clay. It refers both to the increased concentration of suspended sediments and to the increased accumulation (temporary or permanent) of fine sediments on bottoms where they are undesirable. Siltation is most often caused by soil erosion or sediment spill. It is sometimes referred to by the ambiguous term "sediment pollution", which can also refer to a chemical contamination of sediments accumulated on the bottom, or to pollutants bound to sediment particles. Although "siltation" is not perfectly stringent, since it also includes particle sizes other than silt, it is preferred for its lack of ambiguity. Causes The origin of the increased sediment transport into an area may be erosion on land or activities in the water. In rural areas, the erosion source is typically soil degradation by intensive or inadequate agricultural practices, leading to soil eros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon Dioxide
Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transparent to visible light but absorbs infrared radiation, acting as a greenhouse gas. It is a trace gas in Earth's atmosphere at 421 parts per million (ppm), or about 0.04% by volume (as of May 2022), having risen from pre-industrial levels of 280 ppm. Burning fossil fuels is the primary cause of these increased CO2 concentrations and also the primary cause of climate change.IPCC (2022Summary for policy makersiClimate Change 2022: Mitigation of Climate Change. Contribution of Working Group III to the Sixth Assessment Report of the Intergovernmental Panel on Climate Change Cambridge University Press, Cambridge, United Kingdom and New York, NY, USA Carbon dioxide is soluble in water and is found in groundwater, lakes, ice caps, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lake Nyos
Lake Nyos ( ) is a crater lake in the Region of Cameroon, located about northwest of Yaoundé, the capital. Nyos is a deep lake high on the flank of an inactive volcano in the Oku volcanic plain along the Cameroon line of volcanic activity. A volcanic dam impounds the lake waters. A pocket of magma lies beneath the lake and leaks carbon dioxide () into the water, changing it into carbonic acid. Nyos is one of only three lakes known to be saturated with carbon dioxide in this way, and therefore prone to limnic eruptions (the others being Lake Monoun, also in Cameroon, and Lake Kivu in the Democratic Republic of Congo and Rwanda). In 1986, possibly as the result of a landslide, Lake Nyos suddenly emitted a large cloud of , which suffocated 1,746 people and 3,500 livestock in nearby towns and villages, the most notable one being Chah, which was abandoned after the incident. Though not completely unprecedented, it was the first known large-scale asphyxiation caused b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coptodon
''Coptodon'' is a genus of cichlids native to fresh, brackish and coastal marine waters in Africa with ''C. zillii'' also found in the Middle East. It is the only genus in the tribe Coptodonini. Formerly included in ''Tilapia'', this genus and tribe was separated in 2013.Dunz, A.R. & Schliewen, U.K. (2013): Molecular phylogeny and revised classification of the haplotilapiine cichlid fishes formerly referred to as ''“Tilapia”''. ''Molecular Phylogenetics and Evolution, Available online 29 March 2013 doi: 10.1016/j.ympev.2013.03.015'' Despite the change in genus, ''Coptodon'' spp. are still referred to by the common name tilapia. Several species are important in local fisheries and a few are aquacultured. Appearance Depending on the exact species, the maximum length of ''Coptodon'' ranges from ; the smallest is ''C. snyderae'', which also is the smallest tilapia. Although the individual species typically have different nonbreeding and breeding colors, the sexes are alike. Some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Of Cameroon
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. Mos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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