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Xiphophorus Roseni
''Xiphophorus'' is a genus of euryhaline and freshwater fishes in the family Poeciliidae of order Cyprinodontiformes, native to Mexico and northern Central America. ''Xiphophorus'' species can be divided into three groups based on their evolutionary relationships: platyfish (or platies), northern swordtails, and southern swordtails. Platyfish formerly were classified in another genus, ''Platypoecilus'', which is now obsolete. The type species is ''X. hellerii,'' the green swordtail. Like most other new world Poeciliids, platies and swordtails are live-bearers that use internal fertilization and give birth to live young instead of laying eggs like the bulk of the world's fishes. The name ''Xiphophorus'' derives from the Greek words ξίφος (dagger) and φόρος (bearer), referring to the gonopodium on the males. All are relatively small fishes, which reach a maximum length of depending on the exact species involved. Distribution and conservation status The various ''Xi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Green Swordtail
The green swordtail (''Xiphophorus hellerii'') is a species of freshwater/brackish fish in family Poeciliidae of order Cyprinodontiformes. A live-bearer, it is closely related to the southern platyfish or 'platy' (''X. maculatus'') and can crossbreed with it. It is native to an area of North and Central America stretching from Veracruz, Mexico, to northwestern Honduras. Description The male green swordtail grows to a maximum overall length of and the female to . The name 'swordtail' is derived from the elongated lower lobe of the male's caudal fin (tailfin). Sexual dimorphism is moderate, with the female being larger than the male, but lacking the 'sword'. The wild form is olive green in color, with a red or brown lateral stripe and speckles on the dorsal and, sometimes, caudal fins. The male's 'sword' is yellow, edged in black below. Captive breeding has produced many color varieties, including black, red, and many patterns thereof, for the aquarium hobby. All varietie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Belize
Belize is a country on the north-eastern coast of Central America. It is bordered by Mexico to the north, the Caribbean Sea to the east, and Guatemala to the west and south. It also shares a maritime boundary with Honduras to the southeast. Part of the Caribbean region, Belize is a member of the Caribbean Community (CARICOM) and the Commonwealth Caribbean, the historical British West Indies. The Maya civilization spread into the area of Belize between 1500 BCE and 300 CE and flourished until about 1200. European contact began in 1502–04 when Christopher Columbus sailed along the Gulf of Honduras. European exploration was begun by English settlers in 1638. Spanish Empire, Spain and Kingdom of Great Britain, Britain both laid claim to the land until Britain defeated the Spanish in the Battle of St. George's Caye (1798). It became British Honduras, a British colony in 1840, and a Crown colony in 1862. Belize achieved its independence from the United Kingdom on 21 September ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphophorus Andersi
''Xiphophorus'' is a genus of euryhaline and freshwater fishes in the family Poeciliidae of order (biology), order Cyprinodontiformes, native to Mexico and northern Central America. ''Xiphophorus'' species can be divided into three groups based on their evolutionary relationships: platyfish (or platies), northern swordtails, and southern swordtails. Platyfish formerly were classified in another genus, ''Platypoecilus'', which is now obsolete. The type species is ''X. hellerii,'' the green swordtail. Like most other new world Poeciliids, platies and swordtails are Livebearers, live-bearers that use internal fertilization and give birth to live young instead of laying eggs like the bulk of the world's fishes. The name ''Xiphophorus'' derives from the Greek language, Greek words ξίφος (dagger) and φόρος (bearer), referring to the Fish fin#Reproduction, gonopodium on the males. All are relatively small fishes, which reach a maximum length of depending on the exact specie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Union For Conservation Of Nature
The International Union for Conservation of Nature (IUCN) is an international organization working in the field of nature conservation and sustainable use of natural resources. Founded in 1948, IUCN has become the global authority on the status of the natural world and the measures needed to safeguard it. 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 partners ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coatzacoalcos River
The Coatzacoalcos is a large river that feeds mainly the south part of the state of Veracruz; it originates in the Sierra de Niltepec and crosses the state of Oaxaca in the region of the Isthmus of Tehuantepec, flowing for toward the Gulf of Mexico. Tributaries include El Corte, Sarabia, Jaltepec, Chalchijalpa, El Chiquito, Uxpanapa, and Calzadas. The merging of all these rivers creates one of the largest current flows in the entire region. Two-thirds of the streams are navigable. Juan de Grijalva's 1518 expedition encountered the river.Diaz, B., 1963, The Conquest of New Spain, London: Penguin Books, Hernán Cortés sent Diego de Ordaz to explore the river as a possible port. History The Coatzacoalcos River is one of the most important rivers in Mexico. The oldest map of this river was drawn by Francisco Gali in 1580. Unlike most maps made in New Spain in the last quarter of the sixteenth century, this map is purely European in style and is somewhat reminiscent of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pánuco River
The Pánuco River (, ), also known as the ''Río de Canoas'', is a river in Mexico fed by several tributaries including the Moctezuma River and emptying into the Gulf of Mexico. The river is approximately long and passes through or borders the states of Mexico, Hidalgo, Querétaro, San Luis Potosí, Tamaulipas, and Veracruz. According to the ''Atlas of Mexico'', it is the fourth-largest river in Mexico by volume of runoff, and forms the sixth-largest river basin in Mexico by area. The Pánuco is formed by the confluence of its two main tributaries, the Moctezuma River, Moctezuma and the Tampaón (or Tamuín). The Moctezuma originates on the Mexican Plateau, and its headwater streams include the Tula River. It runs northward, forming the state border between Hidalgo and Querétaro as it moves toward San Luis Potosí, before turning eastward to carve a deep canyon through the Sierra Madre Oriental. Once emerging onto the Gulf Coastal Plain, it runs northeastwards, joined fr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sympatry
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 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphophorus Signum
''Xiphophorus signum'' is a poeciliid fish endemic to Guatemala. It occurs in only one creek and adjacent pools, making it a vulnerable species. ''X. signum'' was originally described as a deep-bodied subspecies of '' X. helleri'' by Rosen and Kallman in 1969. It was elevated by Rosen to the species level ten years later. Its scientific name, ''signum'', refers to the distinctive black mark on the caudal fin. Rosen and Kallman speculated that ''X. signum'' may be a sister species of '' X. guentheri'' because it is found in an isolated area in the middle of the natural range of ''X. guentheri'', unless the latter species' range had expanded after ''X. signum'' appeared in its own. A distinctive trait of ''X. signum'' is the elongate black spot at the base of the caudal fin, which appears in both sexes when they reach the length of 1 cm and becomes obscured in adult males as their "sword" grows. The body is predominantly greenish and features only one horizontal stripe on each of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xiphophorus Mayae
''Xiphophorus mayae'' is a fish in the family Poeciliidae. It is found in Central America: eastern Guatemala and western Honduras. This species has red lines on its body which extend on to the upper portion of the caudal fin Fins are moving appendages protruding from the body of fish that interact with water to generate thrust and help the fish swim. Apart from the tail or caudal fin, fish fins have no direct connection with the back bone and are supported only ..., males have the lower part of the caudal fin extended into a "sword". References mayae Fish described in 2002 {{Poeciliidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chiapas Swordtail
The Chiapas swordtail or upland swordtail (''Xiphophorus alvarezi'') is a species of livebearing freshwater fish of family Poeciliidae, and genus ''Xiphophorus''. It is, therefore, in the same genus as the common platy and the swordtail. The Chiapas swordtail was discovered and first described by Donn E. Rosen in 1960, along with four other species of ''Xiphophorus''. Description Male Chipas swordtails attain up to in length. They have an overall body colour of orange market with pearlescent white spots and with green. The lower part of the caudal fin extends into a long "sword" which is bright green edged with black. The females are drabber, however, they may also have some orange markings on their sides. Females are smaller than males and reach a maximum length of . Distribution The Chiapas swordtail is restricted to eastern Chiapas in Mexico and adjacent parts of Guatemala. Habitat and biology The Chiapas swordtail is found in rivers with fast flows. Their preferred ha ... [...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] |
Introduced Species
An introduced species, alien species, exotic species, adventive species, immigrant species, foreign species, non-indigenous species, or non-native species is a species living outside its native distributional range, but which has arrived there by human activity, directly or indirectly, and either deliberately or accidentally. Non-native species can have various effects on the local ecosystem. Introduced species that become established and spread beyond the place of introduction are considered naturalized. The process of human-caused introduction is distinguished from biological colonization, in which species spread to new areas through "natural" (non-human) means such as storms and rafting. The Latin expression neobiota captures the characteristic that these species are ''new'' biota to their environment in terms of established biological network (e.g. food web) relationships. Neobiota can further be divided into neozoa (also: neozoons, sing. neozoon, i.e. animals) and ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
