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Pseudobarbus Burchelli
Burchell's redfin (''Pseudobarbus burchelli''), also known as the Tradouw redfin, Tradou redfin or Breede redfin, is an African freshwater fish species in the family Cyprinidae. ''P. burchelli'' is the type species of its genus ''Pseudobarbus'', and like all of these is tetraploid. The Berg River redfin (''P. burgi'') is a very close relative. It is endemic to the Western Cape Province of South Africa, where it occurs in the Moeras and Tradouw Rivers. Whether the similar fishes from the Breede River and Heuningnes River are also ''P. burchelli'' is undetermined.Swartz & Impson (2007) Two populations are known with certainty, one in the Moeras River at Barrydale and one at the Tradouw River at Tradouw's Pass. During summer, low water levels cut off gene flow between these two. The species inhabits deeper sections of the rivers' somewhat peaty water. Other fish are rare, and in Burchell's redfin's range these seem to consist of the introduced bluegill (''Lepomis macrochirus'') ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Andrew Smith (zoologist)
Sir Andrew Smith (3 December 1797 – 11 August 1872) was a British surgeon, explorer, ethnologist and zoologist. He is considered the father of zoology in South Africa having described many species across a wide range of groups in his major work, ''Illustrations of the Zoology of South Africa''. Smith was born in Hawick, Roxburghshire. He qualified in medicine at the University of Edinburgh obtaining an M.D. degree in 1819, having joined the Army Medical Services in 1816. South Africa 1820–1837 In 1820 he was ordered to the Cape Colony and was sent to Grahamstown to supervise the medical care of European soldiers and soldiers of the Cape Corps. He was appointed the Albany district surgeon in 1822 and started the first free dispensary for indigent patients in South Africa. He led a scientific expedition into the interior and was able to indulge in his interests of natural history and anthropology. On several occasions, he was sent by governors on confidential missions to vis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Breede River
The Breede River ( af, Breederivier), also known as Breë River, is a river in the Western Cape Province of South Africa. Travelling inland north from the city of Cape Town, the river runs in a west to east direction. The surrounding western mountains formed the first continental divide experienced by European settlers in the 18th century. The Titus River and Dwars River become the Breë River. Sources The first catchment area of the river is in the Skurweberg mountain range close to Ceres. The head waters then runs through the modern day Mitchells Pass before plaining out on its middle course in the Worcester area. The river mouth is in an estuary at Port Beaufort on the Indian Ocean. Tributaries On its course through the Breede River Valley, it is joined by the Holsloot and Smalblaar Rivers, from their catchment areas, the Du Toitskloof and Stettyn mountain ranges. The Hex River with its catchment area in the Hex River Mountains also joins the Breede River from the north-ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Extinct
Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and recover may have been lost before this point. Because a species' potential range may be very large, determining this moment is difficult, and is usually done retrospectively. This difficulty leads to phenomena such as Lazarus taxa, where a species presumed extinct abruptly "reappears" (typically in the fossil record) after a period of apparent absence. More than 99% of all species that ever lived on Earth, amounting to over five billion species, are estimated to have died out. It is estimated that there are currently around 8.7 million species of eukaryote globally, and possibly many times more if microorganisms, like bacteria, are included. Notable extinct animal species include non-avian dinosaurs, saber-toothed cats, dodos, m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Pollution
Water pollution (or aquatic pollution) is the contamination of water bodies, usually as a result of human activities, so that it negatively affects its uses. Water bodies include lakes, rivers, oceans, aquifers, reservoirs and groundwater. Water pollution results when contaminants are introduced into these water bodies. Water pollution can be attributed to one of four sources: sewage discharges, industrial activities, agricultural activities, and urban runoff including stormwater. It can be grouped into surface water pollution (either fresh water pollution or marine pollution) or groundwater pollution. For example, releasing inadequately treated wastewater into natural waters can lead to degradation of these aquatic ecosystems. Water pollution can also lead to water-borne diseases for people using polluted water for drinking, bathing, washing or irrigation. Water pollution reduces the ability of the body of water to provide the ecosystem services (such as drinking water) that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tilapia Sparrmanii
''Tilapia sparrmanii'', the banded tilapia, or vlei kurper, is a widespread and adaptable cichlid fish that is found in warmer freshwater habitats of southern Africa. They prefer water with ample plant cover, and occur naturally as far north as DR Congo and Tanzania. They have been introduced locally in the northern hemisphere. Younger banded tilapia feed on crustaceans and insect larvae, while the adults feed on terrestrial and aquatic plants and other debris. They undertake local migrations and may shoal before and during spawning time. They guard their own eggs, and although they may move eggs or fry in the mouth, they are not known to be actual mouthbrooders like several other tilapia species. This species can reach a length of TL and is an important foodfish. The identity of the person honoured in the specific name is uncertain but it is probably the Swedish naturalist Anders Sparrman (1748-1820) who was in the Cape A cape is a clothing accessory or a sleeveless ou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bluegill
The bluegill (''Lepomis macrochirus''), sometimes referred to as "bream", "brim", "sunny", or "copper nose" as is common in Texas, is a species of North American freshwater fish, native to and commonly found in streams, rivers, lakes, ponds and wetlands east of the Rocky Mountains. It is the type species of the genus ''Lepomis'' (true sunfish), from the family Centrarchidae (sunfishes, crappies and black basses) in the order Perciformes (perch-like fish). Bluegills can grow up to long and about . While their color can vary from population to population, they typically have a very distinctive coloring, with deep blue and purple on the face and gill cover, dark olive-colored bands down the side, and a fiery orange to yellow belly. They are omnivorous and will consume anything they can fit in their mouth, but mostly feed on small aquatic insects and baitfishes. The fish are important prey for bass, other larger sunfish, northern pike and muskellunge, walleye, trout, herons, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peat
Peat (), also known as turf (), is an accumulation of partially decayed vegetation or organic matter. It is unique to natural areas called peatlands, bogs, mires, moors, or muskegs. The peatland ecosystem covers and is the most efficient carbon sink on the planet, because peatland plants capture carbon dioxide (CO2) naturally released from the peat, maintaining an equilibrium. In natural peatlands, the "annual rate of biomass production is greater than the rate of decomposition", but it takes "thousands of years for peatlands to develop the deposits of , which is the average depth of the boreal orthernpeatlands", which store around 415 gigatonnes (Gt) of carbon (about 46 times 2019 global CO2 emissions). Globally, peat stores up to 550 Gt of carbon, 42% of all soil carbon, which exceeds the carbon stored in all other vegetation types, including the world's forests, although it covers just 3% of the land's surface. ''Sphagnum'' moss, also called peat moss, is one of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gene Flow
In population genetics, gene flow (also known as gene migration or geneflow and allele flow) is the transfer of genetic material from one population to another. If the rate of gene flow is high enough, then two populations will have equivalent allele frequencies and therefore can be considered a single effective population. It has been shown that it takes only "one migrant per generation" to prevent populations from diverging due to drift. Populations can diverge due to selection even when they are exchanging alleles, if the selection pressure is strong enough. Gene flow is an important mechanism for transferring genetic diversity among populations. Migrants change the distribution of genetic diversity among populations, by modifying allele frequencies (the proportion of members carrying a particular variant of a gene). High rates of gene flow can reduce the genetic differentiation between the two groups, increasing homogeneity. For this reason, gene flow has been thought to con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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