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Crotalinae
The Crotalinae, commonly known as pit vipers,Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . crotaline snakes (from grc, κρόταλον ''krotalon'' castanet), or pit adders, are a subfamily of vipers found in Eurasia and the Americas. Like all other vipers, they are venomous. They are distinguished by the presence of a heat-sensing pit organ located between the eye and the nostril on both sides of the head. Currently, 23 genera and 155 species are recognized: These are also the only viperids found in the Americas. The groups of snakes represented here include rattlesnakes, lanceheads, and Asian pit vipers. The type genus for this subfamily is '' Crotalus'', of which the type species is the timber rattlesnake, ''C. horridus''. These snakes range in size from the diminutive hump-nosed viper, '' Hypnale hypnale'', that grows to a typical total length (including tail) of only , to the bushmaster, '' Lachesis muta'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Sensing In Snakes
The ability to sense infrared thermal radiation evolved independently in two different groups of snakes, one consisting of the families Boidae (boas) and Pythonidae (pythons), the other of the family Crotalinae (pit vipers). What is commonly called a pit organ allows these animals to essentially "see" radiant heat at wavelengths between 5 and 30 μm. The more advanced infrared sense of pit vipers allows these animals to strike prey accurately even in the absence of light, and detect warm objects from several meters away. It was previously thought that the organs evolved primarily as prey detectors, but recent evidence suggests that it may also be used in thermoregulation and predator detection, making it a more general-purpose sensory organ than was supposed.Greene HW. 1992. The ecological and behavioral context for pitviper evolution. ''In'' Campbell JA, Brodie ED Jr. 1992. Biology of the Pitvipers. Texas: Selva. 467 pp. 17 plates. . Phylogeny and evolution The facial pit un ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rattlesnake
Rattlesnakes are venomous snakes that form the genera '' Crotalus'' and '' Sistrurus'' of the subfamily Crotalinae (the pit vipers). All rattlesnakes are vipers. Rattlesnakes are predators that live in a wide array of habitats, hunting small animals such as birds and rodents. Rattlesnakes receive their name from the rattle located at the end of their tails, which makes a loud rattling noise when vibrated that deters predators or serves as a warning to passers-by. Rattlesnakes are the leading contributor to snakebite injuries in North America, but rarely bite unless provoked or threatened; if treated promptly, the bites are seldom fatal. The 36 known species of rattlesnakes have between 65 and 70 subspecies, all native to the Americas, ranging from British Columbia through Ontario in southern Canada, to central Argentina. The largest rattlesnake, the eastern diamondback, can measure up to in length. Rattlesnakes are preyed upon by hawks, weasels, king snakes, and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicolaus Michael Oppel
Nicolaus Michael Oppel (December 7, 1782 in Schönficht – February 16, 1820 in Munich) was a German naturalist. He was a student of, and worked as an assistant to, André Marie Constant Duméril (1774-1860) at the Muséum national d'histoire naturelle in Paris, France, cataloging and classifying species of reptiles. In 1811 he published a book entitled ''Die Ordnungen, Familien und Gattungen der Reptilien als Prodrom einer Naturgeschichte derselben'', or "The Orders, Families, and Types of Reptiles..." in which he established the order, Squamata, and the families Cheloniidae, Colubridae, and the subfamily Crotalinae, as well as several genera which are still in use by taxonomists today. With Friedrich Tiedemann (1781-1861) and Joseph Liboschitz (1783-1824), he was co-author of ''Naturgeschichte der Amphibien'' ( Natural history of amphibians Amphibians are four-limbed and ectothermic vertebrates of the class Amphibia. All living amphibians belong to the group ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Infrared Radiation
Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around 1 millimeter (300 GHz) to the nominal red edge of the visible spectrum, around 700 nanometers (430 THz). Longer IR wavelengths (30 μm-100 μm) are sometimes included as part of the terahertz radiation range. Almost all black-body radiation from objects near room temperature is at infrared wavelengths. As a form of electromagnetic radiation, IR propagates energy and momentum, exerts radiation pressure, and has properties corresponding to both those of a wave and of a particle, the photon. It was long known that fires emit invisible heat; in 1681 the pioneering experimenter Edme Mariotte showed that glass, though transparent to sunlight, obstructed radiant heat. In 1800 the astronomer Sir William Herschel discovered ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lachesis Muta
''Lachesis muta'', also known as the Southern American bushmaster or Atlantic bushmaster, is a venomous pit viper species found in South America, as well as the island of Trinidad in the Caribbean. Two subspecies are currently recognized, including the nominate subspecies described here. Taxonomy Two additional subspecies, ''L. m. melanocephala'' and ''L. m. stenophrys'', had earlier been recognized. However, both were elevated to species level by Zamudio and Green in 1997 (see '' L. melanocephala'' and '' L. stenophrys''). Subspecies Description Adults grow to an average of 2 to 2.5 m (6½-8 feet), although 3 m (10 feet) is not too unusual. The largest recorded specimen was 3.65 m (almost 12 feet) long, making this the largest of all vipers and the longest venomous snake in the western hemisphere.Mehrtens JM (1987). ''Living Snakes of the World in Color''. New York: Sterling Publishers. 480 pp. . ''Lachesis muta'' is the third longest venomous snake in the world, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Timber Rattlesnake
The timber rattlesnake, canebrake rattlesnake, or banded rattlesnake (''Crotalus horridus'') Wright AH, Wright AA (1957). ''Handbook of Snakes of the United States and Canada''. Ithaca and London: Comstock Publishing Associates, a division of Cornell University Press. (7th printing, 1985). 1,105 pp. (in two volumes). . (''Crotalus horridus'', pp. 956–966.) is a species of pit viper endemic to eastern North America. Like all other pit vipers, it is venomous, with a very toxic bite. ''C. horridus'' is the only rattlesnake species in most of the populous Northeastern United States and is second only to its relatives to the west, the prairie rattlesnake, as the most northerly distributed venomous snake in North America. Conant R (1975). ''A Field Guide to Reptiles and Amphibians of Eastern and Central North America, Second Edition''. (First published in 1958). Boston: Houghton Mifflin Company. xviii + 429 pp. + Plates 1-48. (hardcover), (paperback). (''Crotalus horridus'', pp. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venomous Snake
Venomous snakes are species of the suborder Serpentes that are capable of producing venom, which they use for killing prey, for defense, and to assist with digestion of their prey. The venom is typically delivered by injection using hollow or grooved fangs, although some venomous snakes lack well-developed fangs. Common venomous snakes include the families Elapidae, Viperidae, Atractaspididae, and some of the Colubridae. The toxicity of venom is mainly indicated by murine , while multiple factors are considered to judge the potential danger to humans. Other important factors for risk assessment include the likelihood that a snake will bite, the quantity of venom delivered with the bite, the efficiency of the delivery mechanism, and the location of a bite on the body of the victim. Snake venom may have both neurotoxic and hemotoxic properties. There are about 600 venomous snake species in the world. Evolution The evolutionary history of venomous snakes can be traced back ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Viperidae
The Viperidae (vipers) are a family of snakes found in most parts of the world, except for Antarctica, Australia, Hawaii, Madagascar, and various other isolated islands. They are venomous and have long (relative to non-vipers), hinged fangs that permit deep penetration and injection of their venom. Four subfamilies are currently recognized. They are also known as viperids. The name "viper" is derived from the Latin word ''vipera'', -''ae'', also meaning viper, possibly from ''vivus'' ("living") and ''parere'' ("to beget"), referring to the trait viviparity (giving live birth) common in vipers like most of the species of Boidae. Description All viperids have a pair of relatively long solenoglyphous (hollow) fangs that are used to inject venom from glands located towards the rear of the upper jaws, just behind the eyes. Each of the two fangs is at the front of the mouth on a short maxillary bone that can rotate back and forth. When not in use, the fangs fold back against the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoamine Oxidase
Monoamine oxidases (MAO) () are a family of enzymes that catalyze the oxidation of monoamines, employing oxygen to clip off their amine group. They are found bound to the outer membrane of mitochondria in most cell types of the body. The first such enzyme was discovered in 1928 by Mary Bernheim in the liver and was named tyramine oxidase. The MAOs belong to the protein family of flavin-containing amine oxidoreductases. MAOs are important in the breakdown of monoamines ingested in food, and also serve to inactivate monoamine neurotransmitters. Because of the latter, they are involved in a number of psychiatric and neurological diseases, some of which can be treated with monoamine oxidase inhibitors (MAOIs) which block the action of MAOs. Subtypes and tissue distribution In humans there are two types of MAO: MAO-A and MAO-B. * Both are found in neurons and astroglia. * Outside the central nervous system: ** MAO-A is also found in the liver, pulmonary vascular endot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esterase
An esterase is a hydrolase enzyme that splits esters into an acid and an alcohol in a chemical reaction with water called hydrolysis. A wide range of different esterases exist that differ in their substrate specificity, their protein structure, and their biological function. EC classification/list of enzymes * ''EC 3.1.1'': Carboxylic ester hydrolases ** Acetylesterase (EC 3.1.1.6), splits off acetyl groups *** Cholinesterase **** Acetylcholinesterase, inactivates the neurotransmitter acetylcholine **** Pseudocholinesterase, broad substrate specificity, found in the blood plasma and in the liver ** Pectinesterase (EC 3.1.1.11), clarifies fruit juices * ''EC 3.1.2'': Thiolester hydrolases ** Thioesterase *** Ubiquitin carboxy-terminal hydrolase L1 * ''EC 3.1.3'': Phosphoric monoester hydrolases ** Phosphatase (EC 3.1.3.x), hydrolyses phosphoric acid monoesters into a phosphate ion and an alcohol *** Alkaline phosphatase, removes phosphate groups from many types ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mitochondria
A mitochondrion (; ) is an organelle found in the cells of most Eukaryotes, such as animals, plants and fungi. Mitochondria have a double membrane structure and use aerobic respiration to generate adenosine triphosphate (ATP), which is used throughout the cell as a source of chemical energy. They were discovered by Albert von Kölliker in 1857 in the voluntary muscles of insects. The term ''mitochondrion'' was coined by Carl Benda in 1898. The mitochondrion is popularly nicknamed the "powerhouse of the cell", a phrase coined by Philip Siekevitz in a 1957 article of the same name. Some cells in some multicellular organisms lack mitochondria (for example, mature mammalian red blood cells). A large number of unicellular organisms, such as microsporidia, parabasalids and diplomonads, have reduced or transformed their mitochondria into other structures. One eukaryote, '' Monocercomonoides'', is known to have completely lost its mitochondria, and one multicellular orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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