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Shortfin Molly
''Poecilia mexicana'', commonly known as the shortfin molly or Atlantic molly, is a species of poeciliid fish native to fresh and brackish water in Mexico and Guatemala. One population is found in caves and known as the cave molly. Description The maximum standard length of this fish is . It typically grows to a total length . Distribution and habitat The fish lives in tropical freshwater and brackish water habitats. The shortfin molly is considered benthopelagic. It lives in a pH range between 7.0 and 7.5 at temperatures between 22 and 28 degrees Celsius. The species does not migrate. It is an invasive species in the Muddy River of Nevada, USA. Ecology Speciation In two case studies in Cueva del Azufre and Cueva Luna Azufre in Tabasco, Mexico, the Atlantic molly is experiencing speciation. It is occurring between cave and surface populations as well as between habitats of varying sulfur concentrations. Human significance The fishing industry has no interest in harvesting t ... [...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 Zoology, 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 Naturhistorisches Museum, a position which had remained vacant since the death of Johann Jakob Heckel (1790–1857). (in German). Steindachner's reputation as an Ichthyology, 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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Benthopelagic
The demersal zone is the part of the sea or ocean (or deep lake) consisting of the part of the water column near to (and significantly affected by) the seabed and the benthos. The demersal zone is just above the benthic zone and forms a layer of the larger profundal zone. Being just above the ocean floor, the demersal zone is variable in depth and can be part of the photic zone where light can penetrate, and photosynthetic organisms grow, or the aphotic zone, which begins between depths of roughly and extends to the ocean depths, where no light penetrates. Fish The distinction between demersal species of fish and pelagic species is not always clear cut. The Atlantic cod (''Gadus morhua'') is a typical demersal fish, but can also be found in the open water column, and the Atlantic herring (''Clupea harengus'') is predominantly a pelagic species but forms large aggregations near the seabed when it spawns on banks of gravel. Two types of fish inhabit the demersal zone: those ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poecilia
''Poecilia'' is a genus of fishes in the family Poeciliidae of the order Cyprinodontiformes. These livebearers are native to fresh, brackish and salt water in the Americas, and some species in the genus are euryhaline. A few have adapted to living in waters that contain high levels of toxic hydrogen sulfide ()Palacios, Arias-Rodriguez, Plath, Eifert, Lerp, Lamboj, Voelker, & Tobler (2013). The Rediscovery of a Long Described Species Reveals Additional Complexity in Speciation Patterns of Poeciliid Fishes in Sulfide Springs.' PLoS ONE 8(8): e71069. and a population of '' P. mexicana'' lives in caves (other populations of this species are surface-living). Some common and widespread species are often kept as aquarium fish, while other have very small ranges and are seriously threatened. All species in ''Poecilia'' are called mollies except for the Endler's livebearer (''P. wingei'') and the well-known guppy (''P. reticulata'') which have a distinctly different body shape from the r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orizaba
Orizaba () is a city and municipality in the Mexican state of Veracruz. It is located 20 km west of its sister city Córdoba, and is adjacent to Río Blanco and Ixtaczoquitlán, on Federal Highways 180 and 190. The city had a 2005 census population of 117,273 and is almost coextensive with its small municipality, with only a few small areas outside the city. The municipality's population was 117,289 and it has an area of 27.97 km2 (10.799 sq mi). Naming It is generally understood that the name ''Orizaba'' comes from a Hispanicized pronunciation of the Nahuatl name ''Āhuilizāpan'' 'a: wi li sa: pan'' which means "place of pleasing waters." Another possibility, however, is the word Harish (Jerez de la Frontera, Andalusia, in 16th-century Spanish pronunciation), this place being the hometown of the first Spanish settlers (1521) of Orizaba. Harish or—in a simplified form—Ariz, with the addition (under the influence of the Arabic language) of the gentilic "i" and/or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Locality (biology)
In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the scientific name of every taxon is almost a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Type Specimen
In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set (mathematics), set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Speciation
Speciation is the evolutionary process by which populations evolve to become distinct species. The biologist Orator F. Cook coined the term in 1906 for cladogenesis, the splitting of lineages, as opposed to anagenesis, phyletic evolution within lineages. Charles Darwin was the first to describe the role of natural selection in speciation in his 1859 book ''On the Origin of Species''. He also identified sexual selection as a likely mechanism, but found it problematic. There are four geographic modes of speciation in nature, based on the extent to which speciating populations are isolated from one another: allopatric speciation, allopatric, peripatric speciation, peripatric, parapatric speciation, parapatric, and sympatric speciation, sympatric. Speciation may also be induced artificially, through animal husbandry, agriculture, or laboratory experiments of speciation, laboratory experiments. Whether genetic drift is a minor or major contributor to speciation is the subject of much ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Muddy River (Nevada)
The Muddy River, formerly known as the Moapa River, is a short river located in Clark County, in southern Nevada, United States. It is in the Mojave Desert, approximately north of Las Vegas. Geography The Muddy River is approximately long. It begins as a series of thermal springs in the Moapa Valley Moapa Valley is an unincorporated town in Clark County, Nevada, United States. As of the 2010 census, it had a population of 6,924. The valley in which the community lies, also named Moapa Valley, is about long and lies roughly northwest to sou ... before continuing on its course to Lake Mead, where it drains into the northern arm of the lake near Overton, Nevada. Before the Hoover Dam's construction, the Muddy River flowed into the Virgin River. Near the town of Glendale, Nevada, Glendale the Muddy River collects the flow from the Meadow Valley Wash, forming the principal drainage system for southeastern Nevada. Moapa National Wildlife Refuge The Moapa Valley area is home ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fish Migration
Fish migration is mass relocation by fish from one area or body of water to another. Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres. Such migrations are usually done for better feeding or to reproduce, but in other cases the reasons are unclear. Fish migrations involve movements of schools of fish on a scale and duration larger than those arising during normal daily activities. Some particular types of migration are ''anadromous'', in which adult fish live in the sea and migrate into fresh water to spawn; and ''catadromous'', in which adult fish live in fresh water and migrate into salt water to spawn. Marine forage fish often make large migrations between their spawning, feeding and nursery grounds. Movements are associated with ocean currents and with the availability of food in different areas at different times of year. The migratory movements m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Freshwater
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salts and other total dissolved solids. Although the term specifically excludes seawater and brackish water, it does include non- salty mineral-rich waters such as chalybeate springs. Fresh water may encompass frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/ sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranean rivers and lakes. Fresh water is the water resource that is of the most and immediate use to humans. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of higher plants and most insects, amphibians, reptiles, mammals and birds need fresh water to survive. Fresh wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Samuel Garman
Samuel Walton Garman (June 5, 1843 – September 30, 1927), or "Garmann" as he sometimes styled himself, was a naturalist/zoologist from Pennsylvania. He became noted as an ichthyologist and herpetologist. Biography Garman was born in Indiana County, Pennsylvania, on 5 June 1843. In 1868 he joined an expedition to the American West with John Wesley Powell. He graduated from the Illinois State Normal University in 1870, and for the following year was principal of the Mississippi State Normal School. In 1871, he became professor of natural sciences in Ferry Hall Seminary, Lake Forest, Illinois, and a year later became a special pupil of Louis Agassiz. He was a friend and regular correspondent of the naturalist Edward Drinker Cope, and in 1872 accompanied him on a fossil hunting trip to Wyoming. In 1870 he became assistant director of herpetology and ichthyology at Harvard's Museum of Comparative Zoology. His work was mostly in the classification of fish, especially sharks, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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