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Bryconops Allisoni
''Bryconops allisoni'' is a species of freshwater fish known from the rivers of Brazil. It is a recent addition to the genus (2019), currently considered a member ''incertae sedis''. Its name honors Antonio Machado-Allison, an ichthyologist responsible for a great deal of work on the genus ''Bryconops''. Description The holotype, or first collected specimen, of ''Bryconops allisoni'' was 7.25 cm SL (standard length). Other collected specimens range from 2.76 to 6.86 cm. This makes it slightly smaller than other members of the genus, which usually range from 6 to 8 cm SL. The body is generally slender, deepest in the region of the dorsal fin, and the snout is relatively long, about 23-29% of the length of the head. The scales of ''B. allisoni'' are silvery with a greenish iridescence, and parts of the snout are tinted brown. (Silver or greenish coloration is not uncommon in the genus as a whole.) It bears an iridescent-green lateral stripe that turns black when it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subgenus
In biology, a subgenus (plural: subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the tiger cowry of the Indo-Pacific, ''Cypraea'' (''Cypraea'') ''tigris'' Linnaeus, which belongs to the subgenus ''Cypraea'' of the genus ''Cypraea''. However, it is not mandatory, or even customary, when giving the name of a species, to include the subgeneric name. In the International Code of Nomenclature for algae, fungi, and plants (ICNafp), the subgenus is one of the possible subdivisions of a genus. There is no limit to the number of divisions that are permitted within a genus by adding the prefix "sub-" or in other ways as long as no confusion can result. Article 4 The secondary ranks of section and series are subordinate to subgenus. An example is ''Banksia'' subg. ''Isostylis'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tapajós National Forest
The Tapajós National Forest ( pt, Floresta Nacional do Tapajós) is a Brazilian national forest in the state of Pará, Brazil. It supports sustainable exploitation of the natural resources in an area of Amazon rainforest. Location The Tapajós National Forest has an area of . It is in the municipalities of Belterra, Aveiro, Rurópolis and Placas in the state of Pará. The unit is bounded by the Tapajós, the Cupari River, a tributary of the Tapajós, and the BR-163 Santarém–Cuiabá road. Part of the forest drains into the Tapajós to the west, and part drains into the Curuá Una River basin to the east. The Moju River, a tributary of the Curuá-Una, rises in the forest. The side of the forest along the banks of the Tapajós has elevations of about cut by ravines and deep valleys. The flat areas are periodically flooded in the rainy season. Further from the river the forest is on the Tapajós-Xingu plateau, with elevations of . Environment The Tapajós National Fore ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Illegal Mining
Illegal mining is mining activity that is undertaken without state permission, in particular in absence of land rights, mining licenses, and exploration or mineral transportation permits. Illegal mining can be a subsistence activity, as is the case with artisanal mining, or it can belong to large-scale organized crime, spearheaded by illegal mining syndicates. On an international level, approximately 80 percent of small-scale mining operations can be categorized as illegal. Despite strategic developments towards " responsible mining," even big companies can be involved in illegal mineral digging and extraction, if only on the financing side. Regional Issues Sub-Saharan Africa Spurred by widespread poverty and a lack of alternative income-earning opportunities, illegal artisanal mining is a well-documented phenomenon in sub-Saharan Africa. While legalization opportunities for artisanal and small scale mining are often available, inefficient government bureaucracy structures can m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union For Conservation Of Nature
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 pu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympatry
In biology, two related species or populations are considered sympatric when they exist in the same geographic area and thus frequently encounter one another. 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 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 shared ranges and do not ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tapajós
The Tapajós ( pt, Rio Tapajós ) is a river in Brazil. It runs through the Amazon Rainforest and is a major tributary of the Amazon River. When combined with the Juruena River, the Tapajós is approximately long. It is one of the largest clearwater rivers, accounting for about 6% of the water in the Amazon basin. Course For most of its length the Tapajós runs through Pará State, but the upper (southern) part forms the border between Pará and Amazonas State. The source is at the Juruena–Teles Pires river junction. The Tapajós River basin accounts for 6% of the water in the Amazon Basin, making it the fifth largest in the system.Hales, J., and P. Petry (2013). Tapajos – Juruena'. Freshwater Ecoregions of the World. Retrieved 16 February 2013. From the lower Arinos River (a tributary of Juruena) to the Maranhão Grande falls are a more or less continuous series of formidable cataracts and rapids; but from the Maranhão Grande to the mouth of Tapajós, about , the river ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venezuela
Venezuela (; ), officially the Bolivarian Republic of Venezuela ( es, link=no, República Bolivariana de Venezuela), is a country on the northern coast of South America, consisting of a continental landmass and many islands and islets in the Caribbean Sea. It has a territorial extension of , and its population was estimated at 29 million in 2022. The capital and largest urban agglomeration is the city of Caracas. The continental territory is bordered on the north by the Caribbean Sea and the Atlantic Ocean, on the west by Colombia, Brazil on the south, Trinidad and Tobago to the north-east and on the east by Guyana. The Venezuelan government maintains a claim against Guyana to Guayana Esequiba. Venezuela is a federal presidential republic consisting of 23 states, the Capital District and federal dependencies covering Venezuela's offshore islands. Venezuela is among the most urbanized countries in Latin America; the vast majority of Venezuelans live in the cities of the n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gill Raker
Gill rakers in fish are bony or cartilaginous processes that project from the branchial arch (gill arch) and are involved with suspension feeding tiny prey. They are not to be confused with the gill filaments that compose the fleshy part of the gill used for gas exchange. Rakers are usually present in two rows, projecting from both the anterior and posterior side of each gill arch. Rakers are widely varied in number, spacing, and form. By preventing food particles from exiting the spaces between the gill arches, they enable the retention of food particles in filter feeders. The structure and spacing of gill rakers in fish determines the size of food particles trapped, and correlates with feeding behavior. Fish with densely spaced, elongated, comb-like gill rakers are efficient at filtering tiny prey, whereas carnivores and omnivores often have more widely spaced gill rakers with secondary projections. Because gill raker characters often vary between closely related taxa, they are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Maxilla
The maxilla (plural: ''maxillae'' ) in vertebrates is the upper fixed (not fixed in Neopterygii) bone of the jaw formed from the fusion of two maxillary bones. In humans, the upper jaw includes the hard palate in the front of the mouth. The two maxillary bones are fused at the intermaxillary suture, forming the anterior nasal spine. This is similar to the mandible (lower jaw), which is also a fusion of two mandibular bones at the mandibular symphysis. The mandible is the movable part of the jaw. Structure In humans, the maxilla consists of: * The body of the maxilla * Four processes ** the zygomatic process ** the frontal process of maxilla ** the alveolar process ** the palatine process * three surfaces – anterior, posterior, medial * the Infraorbital foramen * the maxillary sinus * the incisive foramen Articulations Each maxilla articulates with nine bones: * two of the cranium: the frontal and ethmoid * seven of the face: the nasal, zygomatic, lacrimal, inferior n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synapomorphies
In phylogenetics, an apomorphy (or derived trait) is a novel character or character state that has evolved from its ancestral form (or plesiomorphy). A synapomorphy is an apomorphy shared by two or more taxa and is therefore hypothesized to have evolved in their most recent common ancestor. ) In cladistics, synapomorphy implies homology. Examples of apomorphy are the presence of erect gait, fur, the evolution of three middle ear bones, and mammary glands in mammals but not in other vertebrate animals such as amphibians or reptiles, which have retained their ancestral traits of a sprawling gait and lack of fur. Thus, these derived traits are also synapomorphies of mammals in general as they are not shared by other vertebrate animals. Etymology The word —coined by German entomologist Willi Hennig—is derived from the Ancient Greek words (''sún''), meaning "with, together"; (''apó''), meaning "away from"; and (''morphḗ''), meaning "shape, form". Clade analysis T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bryconops
''Bryconops'' is a genus of freshwater fish in the family Iguanodectidae from South America. It consists of small fish, all under half-a-foot long, with slender bodies and silvery scales, though there is some mild color variation. Several species can be identified by way of a humeral patch (a mark near the pectoral fin), and others have a reddish ocellus, or eyespot, on one or both lobes of the dorsal fin. Many ''Bryconops'' prefer clearwater environments with a strong current, though some are partial to slow-moving blackwater, and several are endemic to their locale. The majority of species are from Brazil or Venezuela. Rivers and river basins that house species of ''Bryconops'' include the Tapajos, Orinoco, Tocantins, Negro, and Madeira. Few species of ''Bryconops'' have been evaluated as far as conservation status, but most of them are believed to be low-risk species. The greatest threats to population levels come almost entirely in the form of anthropogenic hazards, inclu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
