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Niger Stingray
The Niger stingray or smooth freshwater stingray (''Dasyatis garouaensis'') is a species of stingray in the family Dasyatidae, native to rivers in Nigeria and Cameroon. Attaining a width of , this species can be distinguished by its thin, almost circular pectoral fin disk, slightly projecting snout tip, and mostly smooth skin with small or absent dermal denticles. The Niger stingray feeds on aquatic insect larvae and is ovoviviparous. The long stinging spine on the tail of this ray can inflict a painful wound. It has been assessed as Critically Endangered by the International Union for Conservation of Nature (IUCN), as its numbers are declining in some areas and it faces heavy fishing pressure and habitat degradation. Taxonomy The original description of the Niger stingray was published by Alfred Stauch and M. Blanc in 1962, in the scientific journal ''Bulletin du Muséum National d'Histoire Naturelle (Série 2)''. The specific epithet ''garouaensis'' refers to the city of Garou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alfred Stauch
Alfred may refer to: Arts and entertainment *''Alfred J. Kwak'', Dutch-German-Japanese anime television series * ''Alfred'' (Arne opera), a 1740 masque by Thomas Arne * ''Alfred'' (Dvořák), an 1870 opera by Antonín Dvořák *"Alfred (Interlude)" and "Alfred (Outro)", songs by Eminem from the 2020 album ''Music to Be Murdered By'' Business and organisations * Alfred, a radio station in Shaftesbury, England *Alfred Music, an American music publisher *Alfred University, New York, U.S. *The Alfred Hospital, a hospital in Melbourne, Australia People * Alfred (name) includes a list of people and fictional characters called Alfred * Alfred the Great (848/49 – 899), or Alfred I, a king of the West Saxons and of the Anglo-Saxons Places Antarctica * Mount Alfred (Antarctica) Australia * Alfredtown, New South Wales * County of Alfred, South Australia Canada * Alfred and Plantagenet, Ontario * Alfred Island, Nunavut * Mount Alfred, British Columbia United States * Alfred, Maine, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Specific Name (zoology)
In zoological nomenclature, the specific name (also specific epithet or species epithet) is the second part (the second name) within the scientific name of a species (a binomen). The first part of the name of a species is the name of the genus or the generic name. The rules and regulations governing the giving of a new species name are explained in the article species description. For example, the scientific name for humans is ''Homo sapiens'', which is the species name, consisting of two names: ''Homo'' is the " generic name" (the name of the genus) and ''sapiens'' is the "specific name". Historically, ''specific name'' referred to the combination of what are now called the generic and specific names. Carl Linnaeus, who formalized binomial nomenclature, made explicit distinctions between specific, generic, and trivial names. The generic name was that of the genus, the first in the binomial, the trivial name was the second name in the binomial, and the specific the proper term for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sanaga River
The Sanaga River (formerly german: Zannaga) is the largest river in Cameroon located in East Region, Centre Region and Littoral Region. Its length is about from the confluence of Djérem and Lom River. The total length of Sanaga-Djérem River system is about . Djerem is the longest source of Sanaga River with a total length of 464.5 km. Course The Sanaga River has its Source at the Adamawa Plateau. It is formed by the confluence of the Djérem River and Lom River in the north of the East Region. Djérem River has a total length of and Lom River has a total length of . Apart from those originating rivers, the largest tributary of Sanaga is Mbam River with a total length of . Climate The Sanaga River forms a boundary between two tropical moist forest ecoregions. The Cross-Sanaga-Bioko coastal forests lie to the north between the Sanaga River and the Cross River of Nigeria, and the Atlantic Equatorial coastal forests extend south of the river through southweste ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niger River
The Niger River ( ; ) is the main river of West Africa, extending about . Its drainage basin is in area. Its source is in the Guinea Highlands in south-eastern Guinea near the Sierra Leone border. It runs in a crescent shape through Mali, Niger, on the border with Benin and then through Nigeria, discharging through a massive delta, known as the Niger Delta (or the Oil Rivers), into the Gulf of Guinea in the Atlantic Ocean. The Niger is the third-longest river in Africa, exceeded by the Nile and the Congo River. Its main tributary is the Benue River. Etymology The Niger has different names in the different languages of the region: * Fula: ''Maayo Jaaliba'' * Manding: ''Jeliba'' or ''Joliba'' "great river" * Tuareg: ''Egerew n-Igerewen'' "river of rivers" * Songhay: ''Isa'' "the river" * Zarma: ''Isa Beeri'' "great river" * Hausa: ''Kwara'' *Nupe: ''Èdù'' * Yoruba: ''Ọya'' "named after the Yoruba goddess Ọya, who is believed to embody the ri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benue River
The Benue River (french: la Bénoué), previously known as the Chadda River or Tchadda, is the major tributary of the Niger River. The river is approximately long and is almost entirely navigable during the summer months. The size of its basin is . As a result, it is an important transportation route in the regions through which it flows. Geography It rises in the Adamawa Plateau of northern Cameroon, from where it flows west, and through the town of Garoua and Lagdo Reservoir, into Nigeria south of the Mandara mountains, and through Jimeta, Ibi and Makurdi before meeting the Niger River at Lokoja. Large tributaries are the Faro River, the Gongola River and the Mayo Kébbi, which connects it with the Logone River (part of the Lake Chad system) during floods. Other tributaries are Taraba River and River Katsina Ala. At the point of confluence, the Benue exceeds the Niger by volume. The mean discharge before 1960 was for the Benue and for the Niger. During the following ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Africa
Africa is the world's second-largest and second-most populous continent, after Asia in both cases. At about 30.3 million km2 (11.7 million square miles) including adjacent islands, it covers 6% of Earth's total surface area and 20% of its land area.Sayre, April Pulley (1999), ''Africa'', Twenty-First Century Books. . With billion people as of , it accounts for about of the world's human population. Africa's population is the youngest amongst all the continents; the median age in 2012 was 19.7, when the worldwide median age was 30.4. Despite a wide range of natural resources, Africa is the least wealthy continent per capita and second-least wealthy by total wealth, behind Oceania. Scholars have attributed this to different factors including geography, climate, tribalism, colonialism, the Cold War, neocolonialism, lack of democracy, and corruption. Despite this low concentration of wealth, recent economic expansion and the large and young population make Afr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pincushion Ray
The pincushion ray (''Dasyatis ukpam'') or thorny freshwater stingray, is a little-known species of stingray in the family Dasyatidae, found in the rivers and lakes of West and Middle Africa. A heavy-bodied ray measuring up to across, this species can be distinguished by its rounded pectoral fin disk, reduced or absent stinging tail spine, and—in adults—numerous stout thorns covering its back and tail. In lieu of a long tail spine as in other stingrays, the pincushion ray employs these thorny denticles in defense. Seldom encountered since it was originally described, this species has been assessed as Critically Endangered by the International Union for Conservation of Nature (IUCN). Taxonomy John Alexander Smith scientifically described the pincushion ray in 1863, in ''Proceedings of the Royal Physical Society of Edinburgh''. He named it ''ukpam'', as that is the local indigenous name for freshwater stingrays. Because he saw the single, reduced tail spine of this ray as an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dasyatis
''Dasyatis'' (Greek δασύς ''dasýs'' meaning rough or dense and βατίς ''batís'' meaning skate) is a genus of stingray in the family Dasyatidae that is native to the Atlantic, including the Mediterranean. In a 2016 taxonomic revision, many of the species formerly assigned to ''Dasyatis'' were reassigned to other genera (''Bathytoshia'', ''Fontitrygon'', ''Hemitrygon'', '' Hypanus'', ''Megatrygon'' and ''Telatrygon''). Species *'' Dasyatis dipterura'' ( D. S. Jordan & C. H. Gilbert, 1880) (diamond stingray) *''Dasyatis chrysonota'' A. Smith, 1828 (blue stingray) *'' Dasyatis hypostigma'' H. R. S. Santos & M. R. de Carvalho, 2004 (groovebelly stingray) *''Dasyatis marmorata'' Steindachner, 1892 (marbled stingray) *''Dasyatis pastinaca'' Linnaeus, 1758 (common stingray) *'' Dasyatis tortonesei'' Capapé, 1975 (Tortonese's stingray) Fossil species * † '' Dasyatis africana'' Arambourg, 1947 See also * List of prehistoric cartilaginous fish This list of prehi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physiology
Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical and physical functions in a living system. According to the classes of organisms, the field can be divided into medical physiology, animal physiology, plant physiology, cell physiology, and comparative physiology. Central to physiological functioning are biophysical and biochemical processes, homeostatic control mechanisms, and communication between cells. ''Physiological state'' is the condition of normal function. In contrast, ''pathological state'' refers to abnormal conditions, including human diseases. The Nobel Prize in Physiology or Medicine is awarded by the Royal Swedish Academy of Sciences for exceptional scientific achievements in physiology related to the field of medicine. Foundations Cells Although there are differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Morphology (biology)
Morphology is a branch of biology dealing with the study of the form and structure of organisms and their specific structural features. This includes aspects of the outward appearance (shape, structure, colour, pattern, size), i.e. external morphology (or eidonomy), as well as the form and structure of the internal parts like bones and organs, i.e. internal morphology (or anatomy). This is in contrast to physiology, which deals primarily with function. Morphology is a branch of life science dealing with the study of gross structure of an organism or taxon and its component parts. History The etymology of the word "morphology" is from the Ancient Greek (), meaning "form", and (), meaning "word, study, research". While the concept of form in biology, opposed to function, dates back to Aristotle (see Aristotle's biology), the field of morphology was developed by Johann Wolfgang von Goethe (1790) and independently by the German anatomist and physiologist Karl Friedrich Burdach ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the southern subregion of a single continent called America. South America is bordered on the west by the Pacific Ocean and on the north and east by the Atlantic Ocean; North America and the Caribbean Sea lie to the northwest. The continent generally includes twelve sovereign states: Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Guyana, Paraguay, Peru, Suriname, Uruguay, and Venezuela; two dependent territories: the Falkland Islands and South Georgia and the South Sandwich Islands; and one internal territory: French Guiana. In addition, the ABC islands of the Kingdom of the Netherlands, Ascension Island (dependency of Saint Helena, Ascension and Tristan da Cunha, a British Overseas Territory), Bouvet Island ( dependency of Norway), Pa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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