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Crenicichla Urosema And Virgatula (middle Rio Xingu)
''Crenicichla'' is a genus of cichlids native to South America commonly known as the pike cichlids. They are found in most tropical and subtropical freshwater habitats between the Andes and the Atlantic. Description The smallest species of ''Crenicichla'' are no larger than Gottwald, J: Crenicichla arten.' and may be referred to as "dwarf cichlids" for the aquarium hobby – though their aggressive and territorial habits make them unsuitable for novice keepers. The smallest members, and formerly the ''C. wallacii'' species complex was split off to ''Wallaciia'' in 2023, along with the former ''C. saxatilis'' complex which became ''Saxatilia'' and the ''C. lugubris'' complex which became ''Lugubria''. In the same paper, one further genus was erected (''Hemeraia'') and the remaining species were divided into subgenera. The largest pike cichlids can grow to about long. Most ''Crenicichla'' measure in the range of . Like many other predatory fishes, a pike cichlid has a wide mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Jakob Heckel
Johann Jakob Heckel (23 January 1790 – 1 March 1857) was an Austrian taxidermist, zoology, zoologist, and ichthyology, ichthyologist from Mannheim in the Electoral Palatinate. He worked at the Royal natural history cabinet in Vienna which later became the Austrian Museum of Natural History. Life Heckel was born in Mannheim, the son of a namesake music teacher and Sophia née Reinhardt. He also had a namesake brother who studied music and was educated at home and lived in Vienna for a while. Another brother was Karl Ferdinand Heckel (1800-1870) who also studied music. In 1805 the family fled the French to Pressburg and then to Pest. Heckel visited the Georgicon agricultural college in 1806. His father bought a farm in Gumpoldskirchen and after the death of his father in December 1811, his mother took over the farm, assisted by his brother. He married Barbara Baumgartner in 1817 and in 1818 he was working at the Vienna Naturaliencabinet (which later became the Naturhistorisches Mu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guiana Shield
The Guiana Shield (; ; ; ) is one of the three cratons of the South American Plate. It is a 1.7 billion-year-old Precambrian geological formation in northeast South America that forms a portion of the northern coast. The higher elevations on the shield are called the Guiana Highlands, which is where the table-like mountains called tepuis are found. The Guiana Highlands are also the source of some of the world's most well-known waterfalls such as Angel Falls, Kaieteur Falls and Cuquenan Falls. The Guiana Shield underlies Guyana (previously ''British Guiana''), Suriname (previously ''Dutch Guiana''), and French Guiana (or ''Guyane''), much of southern Venezuela, as well as parts of Colombia and Brazil. The rocks of the Guiana Shield consist of metasediments and metavolcanics ( greenstones) overlain by sub-horizontal layers of sandstones, quartzites, shales and conglomerates intruded by sills of younger mafic intrusives such as gabbros. Geology The oldest rocks in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crenicichla Cametana
''Crenicichla cametana'' is a species of cichlid Cichlids () are a large, diverse, and widespread family of percomorph fish in the family Cichlidae, order Cichliformes. At least 1,760 species have been scientifically described, making it one of the largest vertebrate families, with on ... native to South America. It is found in the Amazon River basin and in the Tocantins River basin, Brazil. This species reaches a length of . References * cametana Cichlid fish of Brazil Fish of the Amazon basin Taxa named by Franz Steindachner Fish described in 1911 {{Cichlinae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Periphyton
Periphyton is a complex mixture of algae, cyanobacteria, heterotrophic microbes, and detritus that is attached to submerged surfaces in most aquatic ecosystems. The related term Aufwuchs ( German "surface growth" or "overgrowth", ) refers to the collection of small animals and plants that adhere to open surfaces in aquatic environments, such as parts of rooted plants. Periphyton serves as an important food source for invertebrates, tadpoles, and some fish. It can also absorb contaminants, removing them from the water column and limiting their movement through the environment. The periphyton is also an important indicator of water quality; responses of this community to pollutants can be measured at a variety of scales representing physiological to community-level changes. Periphyton has often been used as an experimental system in, e.g., pollution-induced community tolerance studies. Composition In both marine and freshwater environments, algae – particularly green algae a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Holarctic
The Holarctic realm is a biogeographic realm that comprises the majority of habitats found throughout the continents in the Northern Hemisphere. It corresponds to the floristic Boreal Kingdom. It includes both the Nearctic zoogeographical region (which covers most of North America), and Alfred Wallace's Palearctic zoogeographical region (which covers North Africa, and all of Eurasia except for Southeast Asia, the Indian subcontinent, the southern Arabian Peninsula). These regions are further subdivided into a variety of ecoregions. Many ecosystems and the animal and plant communities that depend on them extend across a number of continents and cover large portions of the Holarctic realm. This continuity is the result of those regions’ shared glacial history. Major ecosystems Within the Holarctic realm, there are a variety of ecosystems. The type of ecosystem found in a given area depends on its latitude and the local geography. In the far north, a band of Arctic tun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esox
''Esox'' is a genus of freshwater fish commonly known as pike or pickerel. It is the type genus of the family (biology), family Esocidae. The type species of the genus is ''Esox lucius'', the northern pike. ''Esox'' have a fossil record extending back to the Paleocene. Modern large pike species are native to the Palearctic and Nearctic realms, ranging across Northern America and from Western Europe to Siberia in North Asia. Pike have the elongated, torpedo-like shape typical of predatory fishes, with sharply pointed heads and sharp teeth. Their coloration is typically grey-green with a mottled or spotted appearance with stripes along their backs, providing camouflage among underwater weeds, and each individual pike marking patterns are unique like fingerprints. Pikes can grow to a maximum recorded length of , reaching a maximum recorded weight of 67lb 8oz. Etymology The generic name ''Esox'' (pike fish) derives from the Greek language, Greek ἴσοξ (''ee-soks'', a large f ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptation (biology)
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection. Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle. In 18th and 19th-century natural theology, adaptation was taken as evidence for the existence of a deity. Charles Darwin and Alfred Russel Wallace proposed instead that it was explained by natural selection. Adaptation is related to biological fitness, which governs the rate of evolution as measured by changes in allele frequencies. Often, two or more species co-adapt and co-evolve as they develop adaptations tha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predatory
Predation is a biological interaction in which one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predation behavior varies significantly depending on the organism. Many predators, especially carnivores, have evolved distinct hunting strategies. Pursuit predation involves the active search for and pursuit of prey, whilst ambush predators instead wait for prey to present an opportunity for capture, and often use stealth or aggressive mimicry. Other predators are opportunistic or omnivorous and only practice predation occasionally. Most obligate carnivores are specialized for hunting. They may have ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rheophilic
A rheophile is an animal that prefers to live in fast-moving water. Examples of rheophilic animals Insects *Many aquatic insects living in riffles require current to survive. *'' Epeorus sylvicola'', a rheophilic mayfly species ( Ephemeroptera) *Some African (''Elattoneura'') and Asian threadtail (''Prodasineura'') species Birds * Dippers (''Cinclus'') * Grey wagtail (''Motacilla cinerea'') and mountain wagtail (''Motacilla clara'') *A few swifts often nest behind waterfalls, including American black swift (''Cypseloides niger''), giant swiftlet (''Hydrochous gigas''), great dusky swift (''Cypseloides senex'') and white-collared swift (''Streptoprocne zonaris'') *Some waterfowl, including African black duck (''Anas sparsa''), blue duck (''Hymenolaimus malacorhynchos''), Brazilian merganser (''Mergus octosetaceus''), bronze-winged duck (''Speculanas specularis''), harlequin duck (''Histrionicus histrionicus''), Salvadori's teal (''Salvadorina waigiuensis'') and tor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
River 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 interio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argentina
Argentina, officially the Argentine Republic, is a country in the southern half of South America. It covers an area of , making it the List of South American countries by area, second-largest country in South America after Brazil, the fourth-largest country in the Americas, and the List of countries and dependencies by area, eighth-largest country in the world. Argentina shares the bulk of the Southern Cone with Chile to the west, and is also bordered by Bolivia and Paraguay to the north, Brazil to the northeast, Uruguay and the South Atlantic Ocean to the east, and the Drake Passage to the south. Argentina is a Federation, federal state subdivided into twenty-three Provinces of Argentina, provinces, and one autonomous city, which is the federal capital and List of cities in Argentina by population, largest city of the nation, Buenos Aires. The provinces and the capital have their own constitutions, but exist under a Federalism, federal system. Argentina claims sovereignty ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Río Negro (Argentina)
Río Negro (; ''Black River'') is the main river of Patagonia in terms of the size of its drainage basin, its associated agricultural produce and population living at its shores. In eastern Patagonia it is also the largest by flow rate. The river flows through the Argentine province of Río Negro which is named after it. Its name comes from the literal translation of the Mapuche term ''Curu Leuvu'', although the water is more green than black. Formerly, it was also known as "river of the willows" because of the big number of weeping willows that grow along the bank. It is 635 km in length. It originates from the junction of the Limay River and Neuquén River at the border with the Neuquén Province, and flows southeast incised through steppes to the Atlantic Ocean at , near El Cóndor beach resort some downstream from Viedma, Río Negro province's capital. The river allows the Río Negro province to produce 70% of the pears and 72% of the apples of Argentina. The main a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
