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Iberian Barbel
The Iberian barbel (''Luciobarbus comizo'') is a ray-finned fish species in the family Cyprinidae. It is here placed in '' Luciobarbus'' following the IUCN, but that genus is very closely related to the other typical barbels and perhaps better considered a mere subgenus of ''Barbus''. This large barbel can grow to over long. Natural hybrids of this barbel and the closely related '' L. bocagei'' are not uncommon in the middle Tagus river. The two species and their hybrids are hard to distinguish, but ''L. comizo'' usually has a longer and more narrow snout, and the last unbranched ray of the dorsal fin has a longer denticulated section but with more widely spaced denticles. In the first two traits the hybrids are intermediate between their parent species, in the latter they are closer to the Iberian Barbel. Also, the two species are distinguished by their microhabitat preferences where they are sympatric, with ''L. bocagei'' inhabiting somewhat faster-moving parts of the river. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franz Steindachner
Franz Steindachner (11 November 1834 in Vienna – 10 December 1919 in Vienna) was an Austrian zoologist, ichthyologist, and herpetologist. He published over 200 papers on fishes and over 50 papers on reptiles and amphibians. Steindachner described hundreds of new species of fish and dozens of new amphibians and reptiles. At least seven species of reptile have been named after him. Work and career Being interested in natural history, Steindachner took up the study of fossil fishes on the recommendation of his friend Eduard Suess (1831–1914). In 1860 he was appointed to the position of director of the fish collection at the Natural History Museum, Vienna, a position which had remained vacant since the death of Johann Jakob Heckel (1790–1857). (in German). Steindachner's reputation as an ichthyologist grew, and in 1868 he was invited by Louis Agassiz (1807–1873) to accept a position at the Museum of Comparative Zoology at Harvard University. Steindachner took part i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympatric
In biology, two closely related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter each other. An initially interbreeding population that splits into two or more distinct species sharing a common range exemplifies sympatric speciation. Such speciation may be a product of reproductive isolation – which prevents hybrid offspring from being viable or able to reproduce, thereby reducing gene flow – that results in genetic divergence. Sympatric speciation may, but need not, arise through secondary contact, which refers to speciation or divergence in allopatry followed by range expansions leading to an area of sympatry. Sympatric species or taxa in secondary contact may or may not hybrid (biology), interbreed. Types of populations Four main types of population pairs exist in nature. Sympatric populations (or species) contrast with parapatric populations, which contact one another in adjacent but not sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Habitat
In ecology, habitat refers to the array of resources, biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species' habitat can be seen as the physical manifestation of its ecological niche. Thus "habitat" is a species-specific term, fundamentally different from concepts such as Biophysical environment, environment or vegetation assemblages, for which the term "habitat-type" is more appropriate. The physical factors may include (for example): soil, moisture, range of temperature, and Luminous intensity, light intensity. Biotic index, Biotic factors include the availability of food and the presence or absence of Predation, predators. Every species has particular habitat requirements, habitat generalist species are able to thrive in a wide array of environmental conditions while habitat specialist species require a very limited set of factors to survive. The habitat of a species is not necessarily found in a ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drainage Basin
A drainage basin is an area of land in which all flowing surface water converges to a single point, such as a river mouth, or flows into another body of water, such as a lake or ocean. A basin is separated from adjacent basins by a perimeter, the drainage divide, made up of a succession of elevated features, such as ridges and hills. A basin may consist of smaller basins that merge at river confluences, forming a hierarchical pattern. Other terms for a drainage basin are catchment area, catchment basin, drainage area, river basin, water basin, and impluvium. In North America, they are commonly called a watershed, though in other English-speaking places, " watershed" is used only in its original sense, that of the drainage divide line. A drainage basin's boundaries are determined by watershed delineation, a common task in environmental engineering and science. In a closed drainage basin, or endorheic basin, rather than flowing to the ocean, water converges toward the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guadiana River
The Guadiana River ( , , , ) is an international river defining a long stretch of the Portugal-Spain border, separating Extremadura and Andalusia (Spain) from Alentejo and Algarve (Portugal). The river's basin extends from la Mancha and the eastern portion of Extremadura to the southern provinces of the Algarve; the river and its tributaries flow from east to west, then south through Portugal to the border towns of Vila Real de Santo António (Portugal) and Ayamonte (Spain), where it flows into the Gulf of Cádiz. With a course that covers a distance of , it is the fourth-longest in the Iberian Peninsula, and its hydrological basin extends over an area of approximately (the majority of which lies within Spain). Etymology Ptolemy's ''Geography'' recorded the Celtiberian name as ''Anas'', meaning a marshy area or bayou. The Romans adapted this name as , which was etymolygised as the "River of Ducks." After the Muslim conquest of the Iberian Peninsula, the name was extended ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tagus
The Tagus ( ; ; ) is the longest river in the Iberian Peninsula. The river rises in the Montes Universales between Cuenca and Teruel, in mid-eastern Spain, flows , generally westward, and empties into the Atlantic Ocean in Lisbon. Name The river's Latin name is ''Tagus''. While the etymology is unclear, the most probable etymological origin for the hydronym ''Tagus'' is Indo-European *(s)tag- ('to drip'). Geography Source The Tagus River originates at an elevation of 1,593 meters above sea level in a place known as Fuente García, within the municipality of Frías de Albarracín in Teruel, Spain. Its source is located between the Muela de San Juan (1,830 m) and Cerro de San Felipe (1,839 m), in the Sierra de Albarracín, which belongs to the Montes Universales in the western branch of the Iberian System. Course The river flows through Spain for , passing through four autonomous communities (Aragón, Castilla-La Mancha, Madrid, and Extremadura) and a total of six ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reservoir
A reservoir (; ) is an enlarged lake behind a dam, usually built to water storage, store fresh water, often doubling for hydroelectric power generation. Reservoirs are created by controlling a watercourse that drains an existing body of water, interrupting a watercourse to form an Bay, embayment within it, excavating, or building any number of retaining walls or levees to enclose any area to store water. Types Dammed valleys Dammed reservoirs are artificial lakes created and controlled by a dam constructed across a valley and rely on the natural topography to provide most of the basin of the reservoir. These reservoirs can either be ''on-stream reservoirs'', which are located on the original streambed of the downstream river and are filled by stream, creeks, rivers or rainwater that surface runoff, runs off the surrounding forested catchments, or ''off-stream reservoirs'', which receive water diversion, diverted water from a nearby stream or aqueduct (water supply), aq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River
A river is a natural stream of fresh water that flows on land or inside Subterranean river, caves towards another body of water at a lower elevation, such as an ocean, lake, or another river. A river may run dry before reaching the end of its course if it runs out of water, or only flow during certain seasons. Rivers are regulated by the water cycle, the processes by which water moves around the Earth. Water first enters rivers through precipitation, whether from rainfall, the Runoff (hydrology), runoff of water down a slope, the melting of glaciers or snow, or seepage from aquifers beneath the surface of the Earth. Rivers flow in channeled watercourses and merge in confluences to form drainage basins, or catchments, areas where surface water eventually flows to a common outlet. Rivers have a great effect on the landscape around them. They may regularly overflow their Bank (geography), banks and flood the surrounding area, spreading nutrients to the surrounding area. Sedime ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spain
Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Europe and the fourth-most populous European Union member state. Spanning across the majority of the Iberian Peninsula, its territory also includes the Canary Islands, in the Eastern Atlantic Ocean, the Balearic Islands, in the Western Mediterranean Sea, and the Autonomous communities of Spain#Autonomous cities, autonomous cities of Ceuta and Melilla, in mainland Africa. Peninsular Spain is bordered to the north by France, Andorra, and the Bay of Biscay; to the east and south by the Mediterranean Sea and Gibraltar; and to the west by Portugal and the Atlantic Ocean. Spain's capital and List of largest cities in Spain, largest city is Madrid, and other major List of metropolitan areas in Spain, urban areas include Barcelona, Valencia, Seville, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Portugal
Portugal, officially the Portuguese Republic, is a country on the Iberian Peninsula in Southwestern Europe. Featuring Cabo da Roca, the westernmost point in continental Europe, Portugal borders Spain to its north and east, with which it shares Portugal-Spain border, the longest uninterrupted border in the European Union; to the south and the west is the North Atlantic Ocean; and to the west and southwest lie the Macaronesia, Macaronesian archipelagos of the Azores and Madeira, which are the two Autonomous Regions of Portugal, autonomous regions of Portugal. Lisbon is the Capital city, capital and List of largest cities in Portugal, largest city, followed by Porto, which is the only other Metropolitan areas in Portugal, metropolitan area. The western Iberian Peninsula has been continuously inhabited since Prehistoric Iberia, prehistoric times, with the earliest signs of Human settlement, settlement dating to 5500 BC. Celts, Celtic and List of the Pre-Roman peoples of the Iberia ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iberian Peninsula
The Iberian Peninsula ( ), also known as Iberia, is a peninsula in south-western Europe. Mostly separated from the rest of the European landmass by the Pyrenees, it includes the territories of peninsular Spain and Continental Portugal, comprising most of the region, as well as the tiny adjuncts of Andorra, Gibraltar, and, pursuant to the traditional definition of the Pyrenees as the peninsula's northeastern boundary, a small part of France. With an area of approximately , and a population of roughly 53 million, it is the second-largest European peninsula by area, after the Scandinavian Peninsula. Etymology The Iberian Peninsula has always been associated with the River Ebro (Ibēros in ancient Greek and Ibērus or Hibērus in Latin). The association was so well known it was hardly necessary to state; for example, Ibēria was the country "this side of the Ibērus" in Strabo. Pliny the Elder, Pliny goes so far as to assert that the Greeks had called "the whole of the peninsula" Hi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found only 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 also be referred to as an ''endemism'' or, in scientific literature, as an ''endemite''. Similarly, many species found in the Western ghats of India are examples of endemism. Endemism is an important concept in conservation biology for measuring biodiversity in a particular place and evaluating the risk of extinction for species. Endemism is also of interest in evolutionary biology, because it provides clues about how changes in the environment cause species to undergo range shifts (potentially expanding their range into a larger area or b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
