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Distichodus Rufigiensis
''Distichodus rufigiensis'' is a species of freshwater fish in the family Distichodontidae. It is endemic to Tanzania and occurs in the Wami, Rufiji Rufiji may refer to: * Rufiji Delta, a region in Tanzania * Rufiji District, in the Pwani Region of Tanzania * Rufiji River The Rufiji River lies entirely within Tanzania. It is also the largest and longest river in the country. The river is fo ..., and Ruvuma River systems. This species is native to a tropical climate. It inhabits rivers and may also colonized reservoirs. It grows to total length. ''D. rufigiensis'' is decreasing in population due to the threats of illegal fishing, siltation choking its spawning substrate, and land-based pollution. References Distichodus Endemic fauna of Tanzania Fish of Tanzania Taxonomy articles created by Polbot Taxa named by John Roxborough Norman Fish described in 1922 {{Characiformes-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John Roxborough Norman
John Roxborough Norman (1898, Wandsworth, London – 26 May 1944, Berkhamsted, Hertfordshire) was an English ichthyologist. He started as a clerk in a bank. His lifetime affliction with rheumatic fever began during his military service during the First World War. He entered the British Museum in 1921 where he worked for Charles Tate Regan (1878-1943). From 1939 to 1944, he was in charge of the Natural History Museum at Tring as the Curator of Zoology. Norman was the author of, among others, ''A History of Fishes'' (1931) and ''A Draft Synopsis of the Orders, Families and Genera of Recent Fishes'' (1957). He was considered closer to Albert Günther Albert Karl Ludwig Gotthilf Günther FRS, also Albert Charles Lewis Gotthilf Günther (3 October 1830 – 1 February 1914), was a German-born British zoologist, ichthyologist, and herpetologist. Günther is ranked the second-most productive re ... (1830-1914) than to Regan. See also * :Taxa named by John Roxborough Norman Referenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illegal, Unreported And Unregulated Fishing
Illegal, unreported and unregulated fishing (IUU) is an issue around the world. Fishing industry observers believe IUU occurs in most fisheries, and accounts for up to 30% of total catches in some important fisheries. Illegal fishing takes place when vessels or harvesters operate in violation of the laws of a fishery. This can apply to fisheries that are under the jurisdiction of a coastal state or to high seas fisheries regulated by regional fisheries management organisations (RFMO). According to the UN Food and Agriculture Organization (FAO), Fisheries and Aquaculture Department, illegal fishing has caused losses estimated at US$23 billion per year. Unreported fishing is fishing that has been unreported or misreported to the relevant national authority or RFMO, in contravention of applicable laws and regulations. Unregulated fishing generally refers to fishing by vessels without nationality, vessels flying the flag of a country not party to the RFMO governing that fishing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Taxonomy Articles Created By Polbot
Taxonomy is the practice and science of categorization or classification. A taxonomy (or taxonomical classification) is a scheme of classification, especially a hierarchical classification, in which things are organized into groups or types. Among other things, a taxonomy can be used to organize and index knowledge (stored as documents, articles, videos, etc.), such as in the form of a library classification system, or a search engine taxonomy, so that users can more easily find the information they are searching for. Many taxonomies are hierarchies (and thus, have an intrinsic tree structure), but not all are. Originally, taxonomy referred only to the categorisation of organisms or a particular categorisation of organisms. In a wider, more general sense, it may refer to a categorisation of things or concepts, as well as to the principles underlying such a categorisation. Taxonomy organizes taxonomic units known as "taxa" (singular "taxon")." Taxonomy is different from ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Of Tanzania
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 fis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Fauna Of Tanzania
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 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Distichodus
''Distichodus'' is a genus of freshwater fish in the family Distichodontidae found in Africa. Species There are currently 23 recognized species in this genus: *''Distichodus affinis'' Günther, 1873 (Silver distichodus) *''Distichodus altus'' Boulenger, 1899 *''Distichodus antonii'' Schilthuis, 1891Moelants, T., Mbadu Zebe, V., Snoeks, J. & Vreven, E. (2014): A review of the ''Distichodus antonii'' assemblage (Characiformes: Distichodontidae) from the Congo basin. ''Journal of Natural History, 48 (27-28): 1707-1735.'' *''Distichodus atroventralis'' Boulenger, 1898 *''Distichodus brevipinnis'' Günther, 1864 *''Distichodus decemmaculatus'' Pellegrin, 1926 (Dwarf distichodus) *''Distichodus engycephalus'' Günther, 1864 *'' Distichodus fasciolatus'' Boulenger, 1898 (Sharktail distichodus) *''Distichodus hypostomatus'' Pellegrin, 1900 *''Distichodus kolleri'' Holly, 1926 *'' Distichodus langi'' Nichols & Griscom, 1917 *''Distichodus lusosso'' Schilthuis, 1891 (Longsnout ... [...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, rad ... [...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 ero ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population Decline
A population decline (also sometimes called underpopulation, depopulation, or population collapse) in humans is a reduction in a human population size. Over the long term, stretching from prehistory to the present, Earth's total human population has continued to grow; however, current projections suggest that this long-term trend of steady population growth may be coming to an end. Until the beginning of the Industrial Revolution, global population grew very slowly. After about 1800, the growth rate accelerated to a peak of 2.09% annually during the 1967–1969 period, but since then, due to the worldwide collapse of the total fertility rate, it has declined to 1.05% as of 2020. The global growth rate in absolute numbers accelerated to a peak of 92.9 million in 1988, but has declined to 81.3 million in 2020. Long-term projections indicate that the growth rate of the human population of this planet will continue to decline and that by the end of the 21st century, it will reach ze ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish
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 arthrop ... [...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 (shark Sharks are a group of elasmobranch fish chara ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruvuma River
Ruvuma River, formerly also known as the Rovuma River, is a river in the African Great Lakes region. During the greater part of its course, it forms the border between Tanzania and Mozambique (in Mozambique known as ''Rio Rovuma''). The river is long, with a drainage basin of in size. Its mean annual discharge is at its mouth. Overview The lower Ruvuma river is formed by the junction at of two branches of nearly equal importance, the longer of which, the Lujenda, comes from the south-west, the other, which still bears the name Ruvuma, from the west. Its source lies on an undulating plateau, high, immediately to the east of Lake Nyasa, at , the head-stream flowing first due west before turning south and east. In its eastward course, the Ruvuma flows near the base of the escarpment of an arid sandstone plateau to the north, from which direction the streams, which have cut themselves deep channels in the plateau edge, have almost all short courses. On the opposite bank the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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