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Ensatinas
The ensatina (''Ensatina eschscholtzii'') is a species complex of plethodontid (lungless) salamanders found in coniferous forests, oak woodland and chaparralMonterey Ensatina San Diego Field Station, Viewed: April 24, 2005, Last updated: March 05, 2003 from , through , |
Amphibians Of North America
Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group Lissamphibia. They inhabit a wide variety of habitats, with most species living within terrestrial, fossorial, arboreal or freshwater aquatic ecosystems. Thus amphibians typically start out as larvae living in water, but some species have developed behavioural adaptations to bypass this. The young generally undergo metamorphosis from larva with gills to an adult air-breathing form with lungs. Amphibians use their skin as a secondary respiratory surface and some small terrestrial salamanders and frogs lack lungs and rely entirely on their skin. They are superficially similar to reptiles like lizards but, along with mammals and birds, reptiles are amniotes and do not require water bodies in which to breed. With their complex reproductive needs and permeable skins, amphibians are often ecological indicators; in recent decades there has been a dramatic decline ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plethodontid
Plethodontidae, or lungless salamanders, are a family of salamanders. Most species are native to the Western Hemisphere, from British Columbia to Brazil, although a few species are found in Sardinia, Europe south of the Alps, and South Korea. In terms of number of species, they are by far the largest group of salamanders. Biology Adult lungless salamanders have four limbs, with four toes on the fore limbs, and usually with five on the hind limbs. Within many species, mating and reproduction occur solely on land. Accordingly, many species also lack an aquatic larval stage, a phenomenon known as direct development in which the offspring hatch as fully-formed, miniature adults. Direct development is correlated with changes in the developmental characteristics of plethodontids compared to other families of salamanders including increases in egg size and duration of embryonic development. Additionally, the evolutionary loss of the aquatic larval stage is related to a diminishing dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Plethodontidae
Plethodontidae, or lungless salamanders, are a family of salamanders. Most species are native to the Western Hemisphere, from British Columbia to Brazil, although a few species are found in Sardinia, Europe south of the Alps, and South Korea. In terms of number of species, they are by far the largest group of salamanders. Biology Adult lungless salamanders have four limbs, with four toes on the fore limbs, and usually with five on the hind limbs. Within many species, mating and reproduction occur solely on land. Accordingly, many species also lack an aquatic larval stage, a phenomenon known as direct development in which the offspring hatch as fully-formed, miniature adults. Direct development is correlated with changes in the developmental characteristics of plethodontids compared to other families of salamanders including increases in egg size and duration of embryonic development. Additionally, the evolutionary loss of the aquatic larval stage is related to a diminishing dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ensatina Eschscholtzii E
The ensatina (''Ensatina eschscholtzii'') is a species complex of plethodontid (lungless) salamanders found in coniferous forests, oak woodland and chaparralMonterey Ensatina San Diego Field Station, Viewed: April 24, 2005, Last updated: March 05, 2003 from , through , |
Monotypic Amphibian Genera
In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispecific" or "monospecific" is sometimes preferred. In botanical nomenclature, a monotypic genus is a genus in the special case where a genus and a single species are simultaneously described. In contrast, an oligotypic taxon contains more than one but only a very few subordinate taxa. Examples Just as the term ''monotypic'' is used to describe a taxon including only one subdivision, the contained taxon can also be referred to as monotypic within the higher-level taxon, e.g. a genus monotypic within a family. Some examples of monotypic groups are: Plants * In the order Amborellales, there is only one family, Amborellaceae and there is only one genus, '' Amborella'', and in this genus there is only one species, namely ''Amborella trichopoda.' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ensatina Eschscholtzii Platensis (3405603045)
The ensatina (''Ensatina eschscholtzii'') is a species complex of plethodontid (lungless) salamanders found in coniferous forests, oak woodland and chaparralMonterey Ensatina San Diego Field Station, Viewed: April 24, 2005, Last updated: March 05, 2003 from , through , |
Cutaneous Respiration
Cutaneous respiration, or cutaneous gas exchange (sometimes called, skin breathing), is a form of respiration in which gas exchange occurs across the skin or outer integument of an organism rather than gills or lungs. Cutaneous respiration may be the sole method of gas exchange, or may accompany other forms, such as ventilation. Cutaneous respiration occurs in a wide variety of organisms, including insects, amphibians, fish, sea snakes, turtles, and to a lesser extent in mammals. Physical constraints Gas exchange in cutaneous respiration is controlled by three factors: *Ventilation: the rate of delivery of respiratory medium (water or air) to the respiratory surface *Diffusion: the passage of gases through the skin *Convection: the carrying of dissolved gases towards or away from the lungs Taxonomic diversity in chordates Fish Cutaneous respiration occurs in a variety of marine, intertidal, and freshwater fish. For aquatic respiration, fish respire primarily via gills but cutan ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The Ancestor's Tale
''The Ancestor's Tale: A Pilgrimage to the Dawn of Life'' is a science book by Richard Dawkins and Yan Wong on the subject of evolution, which follows the path of humans backwards through evolutionary history, describing some of humanity's cousins as they converge on their common ancestors. The book was first published in 2004 and substantially updated in 2016. It was nominated for the 2005 Aventis Prize for Science Books. Synopsis The book takes a different path backwards through evolution and meets different groupings of organisms. The authors use backward chronology instead of a forward chronology as a way of celebrating the unity of life. In a backward chronology, the ancestors of any set of species must eventually meet at a particular moment. The last common ancestor is the one that they all share which the authors call a "concestor". The oldest concestor is the ancestor of all surviving life forms on this planet. The evidence for this is that all organisms share the sa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interbreeding
In biology, a hybrid is the offspring resulting from combining the qualities of two organisms of different breeds, varieties, species or genera through sexual reproduction. Hybrids are not always intermediates between their parents (such as in blending inheritance), but can show hybrid vigor, sometimes growing larger or taller than either parent. The concept of a hybrid is interpreted differently in animal and plant breeding, where there is interest in the individual parentage. In genetics, attention is focused on the numbers of chromosomes. In taxonomy, a key question is how closely related the parent species are. Species are reproductively isolated by strong barriers to hybridisation, which include genetic and morphological differences, differing times of fertility, mating behaviors and cues, and physiological rejection of sperm cells or the developing embryo. Some act before fertilization and others after it. Similar barriers exist in plants, with differences in flowering tim ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Horseshoe
A horseshoe is a fabricated product designed to protect a horse hoof from wear. Shoes are attached on the palmar surface (ground side) of the hooves, usually nailed through the insensitive hoof wall that is anatomically akin to the human toenail, although much larger and thicker. However, there are also cases where shoes are glued. Horseshoes are available in a wide variety of materials and styles, developed for different types of horse and for the work they do. The most common materials are steel and aluminium, but specialized shoes may include use of rubber, plastic, magnesium, titanium, or copper.Price, Steven D. (ed.) ''The Whole Horse Catalog: Revised and Updated'' New York:Fireside 1998 , pp. 84–87. Steel tends to be preferred in sports in which a strong, long-wearing shoe is needed, such as polo, eventing, show jumping, and western riding events. Aluminium shoes are lighter, making them common in horse racing where a lighter shoe is desired, and often facilitate ce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Valley (California)
The Central Valley is a broad, elongated, flat valley that dominates the interior of California. It is wide and runs approximately from north-northwest to south-southeast, inland from and parallel to the Pacific coast of the state. It covers approximately , about 11% of California's land area. The valley is bounded by the Coast Ranges The Pacific Coast Ranges (officially gazetted as the Pacific Mountain System in the United States) are the series of mountain ranges that stretch along the West Coast of North America from Alaska south to Northern and Central Mexico. Although th ... to the west and the Sierra Nevada to the east. The Central Valley is a list of regions of California, region known for its agricultural productivity: it provides more than half of the fruits, vegetables, and nuts grown in the United States. More than of the valley are irrigated via reservoirs and canals. The valley hosts many cities, including the state capital Sacramento, California, Sacramento ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring Species
In biology, a ring species is a connected series of neighbouring populations, each of which interbreeds with closely sited related populations, but for which there exist at least two "end" populations in the series, which are too distantly related to interbreed, though there is a potential gene flow between each "linked" population and the next. Such non-breeding, though genetically connected, "end" populations may co-exist in the same region ( sympatry) thus closing a "ring". The German term , meaning a circle of races, is also used. Ring species represent speciation and have been cited as evidence of evolution. They illustrate what happens over time as populations genetically diverge, specifically because they represent, in living populations, what normally happens over time between long-deceased ancestor populations and living populations, in which the intermediates have become extinct. The evolutionary biologist Richard Dawkins remarks that ring species "are only showing us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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