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Leptoxis Ampla
''Leptoxis ampla'', common name the round rocksnail, is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusc in the family Pleuroceridae. This species is endemic to the United States, specifically the state of Alabama. The snail has been listed as threatened on the United States Fish and Wildlife Service list of endangered species since 28 October 1998. ''Leptoxis ampla'' is a vulnerable species according to the IUCN Red list. Description The round rocksnail is a pleurocerid snail and its shell grows to about 20 mm (0.8 in) in length. The shell is subglobose, with an ovately rounded aperture. The body whorl is shouldered at the suture, and may be ornamented with folds or plicae. Color may be yellow, dark brown, or olive green, usually with four entire or broken bands.Goodrich C. (1922). "The Anculosae of the Alabama River Drainage". ''Miscellaneous Publications'', Museum of Zoology, University of Michigan (7): 1–57. Lydeard et ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lectotype
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] |
Federal Register
The ''Federal Register'' (FR or sometimes Fed. Reg.) is the official journal of the federal government of the United States that contains government agency rules, proposed rules, and public notices. It is published every weekday, except on federal holidays. The final rules promulgated by a federal agency and published in the ''Federal Register'' are ultimately reorganized by topic or subject matter and codified in the '' Code of Federal Regulations'' (CFR), which is updated annually. The ''Federal Register'' is compiled by the Office of the Federal Register (within the National Archives and Records Administration) and is printed by the Government Publishing Office. There are no copyright restrictions on the ''Federal Register''; as a work of the U.S. government, it is in the public domain. Contents The ''Federal Register'' provides a means for the government to announce to the public changes to government requirements, policies, and guidance. * Proposed new rules and regulat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cahaba River
The Cahaba River is the longest substantially free-flowing river in Alabama and is among the most scenic and biologically diverse rivers in the United States. It is a major tributary of the Alabama River and part of the larger Mobile River basin. With headwaters near Birmingham, the Cahaba flows southwest, then at Heiberger turns southeast and joins the Alabama River at the ghost town and former Alabama capital of Cahaba in Dallas County. Entirely within central Alabama, the Cahaba River is longU.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 27, 2011 and drains an area of . Geography The Cahaba River flows across three physiographic provinces of the state: Appalachian Plateau, Ridge and Valley, and Coastal Plain. The Mobile River basin has the largest Gulf Coast drainage basin east of the Mississippi River, and the Cahaba is one of the seven river systems that contribute to its flow. The mean discharge of water ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coosa River
The Coosa River is a tributary of the Alabama River in the U.S. states of Alabama and Georgia. The river is about long.U.S. Geological Survey. National Hydrography Dataset high-resolution flowline dataThe National Map, accessed April 27, 2011 The Coosa River begins at the confluence of the Oostanaula and Etowah rivers in Rome, Georgia, and ends just northeast of the Alabama state capital, Montgomery, where it joins the Tallapoosa River to form the Alabama River just south of Wetumpka. Around 90% of the Coosa River's length is located in Alabama. Coosa County, Alabama, is located on the Coosa River. The Coosa is one of Alabama's most developed rivers. Most of the river has been impounded, with Alabama Power, a unit of the Southern Company, owning seven dams and powerhouses on the Coosa River. The dams produce hydroelectric power, but they are costly to some species endemic to the Coosa River. History Native Americans had been living on the Coosa Valley for millennia bef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geographical Isolation
Allopatric speciation () – also referred to as geographic speciation, vicariant speciation, or its earlier name the dumbbell model – is a mode of speciation that occurs when biological populations become geographically isolated from each other to an extent that prevents or interferes with gene flow. Various geographic changes can arise such as the continental drift, movement of continents, and the formation of mountains, islands, bodies of water, or glaciers. Human activity such as agriculture or developments can also change the distribution of species populations. These factors can substantially alter a region's geography, resulting in the separation of a species population into isolated subpopulations. The vicariant populations then undergo Genetics, genetic changes as they become subjected to different Natural selection, selective pressures, experience genetic drift, and accumulate different mutations in the separated populations' gene pools. The barriers prevent t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Population
Population typically refers to the number of people in a single area, whether it be a city or town, region, country, continent, or the world. Governments typically quantify the size of the resident population within their jurisdiction using a census, a process of collecting, analysing, compiling, and publishing data regarding a population. Perspectives of various disciplines Social sciences In sociology and population geography, population refers to a group of human beings with some predefined criterion in common, such as location, race, ethnicity, nationality, or religion. Demography is a social science which entails the statistical study of populations. Ecology In ecology, a population is a group of organisms of the same species who inhabit the same particular geographical area and are capable of interbreeding. The area of a sexual population is the area where inter-breeding is possible between any pair within the area and more probable than cross-breeding with in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophoresis
Electrophoresis, from Ancient Greek ἤλεκτρον (ḗlektron, "amber") and φόρησις (phórēsis, "the act of bearing"), is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric field. Electrophoresis of positively charged particles (cations) is sometimes called cataphoresis, while electrophoresis of negatively charged particles (anions) is sometimes called anaphoresis. The electrokinetic phenomenon of electrophoresis was observed for the first time in 1807 by Russian professors Peter Ivanovich Strakhov and Ferdinand Frederic Reuss at Moscow University, who noticed that the application of a constant electric field caused clay particles dispersed in water to migrate. It is ultimately caused by the presence of a charged interface between the particle surface and the surrounding fluid. It is the basis for analytical techniques used in chemistry for separating molecules by size, charge, or binding affinity. Electropho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allozyme
Alloenzymes (or also called allozymes) are variant forms of an enzyme which differ structurally but not functionally from other allozymes coded for by different alleles at the same locus. These are opposed to isozymes, which are enzymes that perform the same function, but which are coded by genes located at different loci. Alloenzymes are common biological enzymes that exhibit high levels of functional evolutionary conservation throughout specific phyla and kingdoms. They are used by phylogeneticists as molecular markers to gauge evolutionary histories and relationships between different species. This can be done because allozymes do not have the same structure. They can be separated by capillary electrophoresis. However, some species are monomorphic for many of their allozymes which would make it difficult for phylogeneticists to assess the evolutionary histories of these species. In these instances, phylogeneticists would have to use another method to determine the evolutionary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sister Species
In phylogenetics, a sister group or sister taxon, also called an adelphotaxon, comprises the closest relative(s) of another given unit in an evolutionary tree. Definition The expression is most easily illustrated by a cladogram: Taxon A and taxon B are sister groups to each other. Taxa A and B, together with any other extant or extinct descendants of their most recent common ancestor (MRCA), form a monophyletic group, the clade AB. Clade AB and taxon C are also sister groups. Taxa A, B, and C, together with all other descendants of their MRCA form the clade ABC. The whole clade ABC is itself a subtree of a larger tree which offers yet more sister group relationships, both among the leaves and among larger, more deeply rooted clades. The tree structure shown connects through its root to the rest of the universal tree of life. In cladistic standards, taxa A, B, and C may represent specimens, species, genera, or any other taxonomic units. If A and B are at the same taxonomic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Painted Rocksnail
The painted rocksnail (''Leptoxis coosaensis,'' formerly ''Leptoxis taeniata'') is a species of freshwater snail with a gill and an operculum, an aquatic gastropod mollusk in the family Pleuroceridae. This species is endemic to the United States, specifically the state of Alabama. The snail has been listed as threatened on the United States Fish and Wildlife Service list of endangered species since October 28, 1998. Description The painted rocksnail is a small to medium-sized pleurocerid snail with a shell that measures about 19 mm (0.8 in) in length, and is subglobose to oval in shape. The aperture is broadly ovate, and rounded anteriorly. The shell coloration varies from yellowish to olive-brown, usually with four dark bands. Some shells do not have these dark bands, and some have the bands broken into square or oblong patches (see Goodrich, 1922Goodrich C. 1922. ''The Anculosae of the Alabama River Drainage''. Miscellaneous Publications, Museum of Zoology, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DNA Sequencing
DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. The advent of rapid DNA sequencing methods has greatly accelerated biological and medical research and discovery. Knowledge of DNA sequences has become indispensable for basic biological research, DNA Genographic Projects and in numerous applied fields such as medical diagnosis, biotechnology, forensic biology, virology and biological systematics. Comparing healthy and mutated DNA sequences can diagnose different diseases including various cancers, characterize antibody repertoire, and can be used to guide patient treatment. Having a quick way to sequence DNA allows for faster and more individualized medical care to be administered, and for more organisms to be identified and cataloged. The rapid speed of sequencing attained with modern D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suture (gastropod)
In anatomy, a suture is a fairly rigid joint between two or more hard elements of an organism, with or without significant overlap of the elements. Sutures are found in the skeletons or exoskeletons of a wide range of animals, in both invertebrates and vertebrates. Sutures are found in animals with hard parts from the Cambrian period to the present day. Sutures were and are formed by several different methods, and they exist between hard parts that are made from several different materials. Vertebrate skeletons The skeletons of vertebrate animals (fish, amphibians, reptiles, birds, and mammals) are made of bone, in which the main rigid ingredient is calcium phosphate. Cranial sutures The skulls of most vertebrates consist of sets of bony plates held together by cranial sutures. These sutures are held together mainly by Sharpey's fibers which grow from each bone into the adjoining one. Sutures in the ankles of land vertebrates In the type of crurotarsal ankle which is found i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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