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Black Widow Spider
''Latrodectus'' is a broadly distributed genus of spiders with several species that are commonly known as the true widows. This group is composed of those often loosely called black widow spiders, brown widow spiders, and similar spiders. However, the diversity of species is much greater. A member of the family Theridiidae, this genus contains 34 species, which include several North American "black widows" (southern black widow ''Latrodectus mactans'', western black widow ''Latrodectus hesperus'', and northern black widow ''Latrodectus variolus''). Besides these, North America also has the red widow ''Latrodectus bishopi'' and the brown widow ''Latrodectus geometricus'', which, in addition to North America, has a much wider geographic distribution. Elsewhere, others include the European black widow (''Latrodectus tredecimguttatus''), the Australian redback black widow (''Latrodectus hasseltii'') and the closely related New Zealand katipō (''Latrodectus katipo''), several differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latrodectus Hesperus
''Latrodectus hesperus'', the western black widow spider or western widow, is a venomous spider species found in western regions of North America. The female's body is 14–16 mm (1/2 in) in length and is black, often with an hourglass-shaped red mark on the lower abdomen. This "hourglass" mark can be yellow, and on rare occasions, white. The male of the species is around half this length and generally a tan color with lighter striping on the abdomen. The population was previously described as a subspecies of ''Latrodectus mactans'' and it is closely related to the northern species ''Latrodectus variolus''. The species, as with others of the genus, build irregular or "messy" webs: unlike the spiral webs or the tunnel-shaped webs of other spiders, the strands of a ''Latrodectus'' web have no apparent organization. Female black widows have potent venom containing a neurotoxin active against a range of mammals (see latrodectism). In humans, symptoms of this venom include pain, n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latrodectus Corallinus
''Latrodectus corallinus'' is a species of widow spider native to Argentina. It is approximately in size, and is primarily black with large, red markings on its abdomen, as well as a red, square-like ring under its abdomen. Distribution and habitat ''Latrodectus corallinus'' is native to Argentina. It is found both outdoors and indoors, and is commonly found in agricultural fields. Habits ''Latrodectus corallinus'', like most species of ''Latrodectus ''Latrodectus'' is a broadly distributed genus of spiders with several species that are commonly known as the true widows. This group is composed of those often loosely called black widow spiders, brown widow spiders, and similar spiders. Howeve ...'', is not aggressive. The peak time of activity for ''Latrodectus corallinus'' is between the months of December and March (summer in the Southern Hemisphere). References External linksUnderside of ''Latrodectus corallinus''(Good view of square-like ring on underside of abdome ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capillary Action
Capillary action (sometimes called capillarity, capillary motion, capillary rise, capillary effect, or wicking) is the process of a liquid flowing in a narrow space without the assistance of, or even in opposition to, any external forces like gravity. The effect can be seen in the drawing up of liquids between the hairs of a paint-brush, in a thin tube, in porous materials such as paper and plaster, in some non-porous materials such as sand and liquefied carbon fiber, or in a biological cell. It occurs because of intermolecular forces between the liquid and surrounding solid surfaces. If the diameter of the tube is sufficiently small, then the combination of surface tension (which is caused by cohesion within the liquid) and adhesive forces between the liquid and container wall act to propel the liquid. Etymology Capillary comes from the Latin word capillaris, meaning "of or resembling hair." The meaning stems from the tiny, hairlike diameter of a capillary. While capilla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digestive Juice
Gastric acid, gastric juice, or stomach acid is a digestive fluid formed within the stomach lining. With a pH between 1 and 3, gastric acid plays a key role in digestion of proteins by activating digestive enzymes, which together break down the long chains of amino acids of proteins. Gastric acid is regulated in feedback systems to increase production when needed, such as after a meal. Other cells in the stomach produce bicarbonate, a base, to buffer the fluid, ensuring a regulated pH. These cells also produce mucus – a viscous barrier to prevent gastric acid from damaging the stomach. The pancreas further produces large amounts of bicarbonate and secretes bicarbonate through the pancreatic duct to the duodenum to neutralize gastric acid passing into the digestive tract. The active components of gastric acid are protons and chloride. Often simplistically described as hydrochloric acid, these species are produced by parietal cells in the gastric glands in the stomach. The secre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Offspring
In biology, offspring are the young creation of living organisms, produced either by a single organism or, in the case of sexual reproduction, two organisms. Collective offspring may be known as a brood or progeny in a more general way. This can refer to a set of simultaneous offspring, such as the chicks hatched from one clutch of eggs, or to all the offspring, as with the honeybee. Human offspring ( descendants) are referred to as children (without reference to age, thus one can refer to a parent's " minor children" or " adult children" or " infant children" or " teenage children" depending on their age); male children are sons and female children are daughters (see kinship). Offspring can occur after mating or after artificial insemination. Offspring contains many parts and properties that are precise and accurate in what they consist of, and what they define. As the offspring of a new species, also known as a child or f1 generation, consist of genes of the father and the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Common Name
In biology, a common name of a taxon or organism (also known as a vernacular name, English name, colloquial name, country name, popular name, or farmer's name) is a name that is based on the normal language of everyday life; and is often contrasted with the scientific name for the same organism, which is Latinized. A common name is sometimes frequently used, but that is not always the case. In chemistry, IUPAC defines a common name as one that, although it unambiguously defines a chemical, does not follow the current systematic naming convention, such as acetone, systematically 2-propanone, while a vernacular name describes one used in a lab, trade or industry that does not unambiguously describe a single chemical, such as copper sulfate, which may refer to either copper(I) sulfate or copper(II) sulfate. Sometimes common names are created by authorities on one particular subject, in an attempt to make it possible for members of the general public (including such interested par ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sexual Cannibalism
Sexual cannibalism is when an animal, usually the female, cannibalizes its mate prior to, during, or after copulation.Polis, G.A. & Farley, R.D. Behavior and Ecology of Mating in the journal of Arachnology 33-46 (1979). It is a trait observed in many arachnid orders and several insect orders. Several hypotheses to explain this seemingly paradoxical behavior have been proposed. The adaptive foraging hypothesis,Blamires, S.J. Nutritional implications for sexual cannibalism in a sexually dimorphic orb web spider. Austral Ecology 36, 389-394 (2011). aggressive spillover hypothesisArnqvist, G. Courtship behaviour and sexual cannibalism in the semi-aquatic fishing spider, DOLOMEDES FIMBRIATUS (CLERCK) (ARANEAE: PISAURIDAE).pdf. The journal of Arachnology 20, 222-226 (1992). and mistaken identity hypothesisGould, S. Only his wings remained. Natural History 93, 10-18 (1984). are among the proposed hypotheses to explain how sexual cannibalism evolved. This behavior is believed to have evolve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Terms Of Location
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of anatom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latrodectus Eye Group
''Latrodectus'' is a broadly distributed genus of spiders with several species that are commonly known as the true widows. This group is composed of those often loosely called black widow spiders, brown widow spiders, and similar spiders. However, the diversity of species is much greater. A member of the family Theridiidae, this genus contains 34 species, which include several North American "black widows" (southern black widow ''Latrodectus mactans'', western black widow ''Latrodectus hesperus'', and northern black widow ''Latrodectus variolus''). Besides these, North America also has the red widow ''Latrodectus bishopi'' and the brown widow ''Latrodectus geometricus'', which, in addition to North America, has a much wider geographic distribution. Elsewhere, others include the European black widow (''Latrodectus tredecimguttatus''), the Australian redback black widow (''Latrodectus hasseltii'') and the closely related New Zealand katipō (''Latrodectus katipo''), several differ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spider Bite
A spider bite, also known as arachnidism, is an injury resulting from the bite of a spider. The effects of most bites are not serious. Most bites result in mild symptoms around the area of the bite. Rarely they may produce a necrotic skin wound or severe pain. Most spiders do not cause bites that are of importance. For a bite to be significant, substantial envenomation is required. Bites from the widow spiders involve a neurotoxic venom which produces a condition known as latrodectism. Symptoms may include pain which may be at the bite or involve the chest and abdomen, sweating, muscle cramps and vomiting among others. Bites from the recluse spiders cause the condition loxoscelism, in which local necrosis of the surrounding skin and widespread breakdown of red blood cells may occur. Headaches, vomiting and a mild fever may also occur. Other spiders that can cause significant bites include the Australian funnel-web spider and South American wandering spider. Efforts to preve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Latrodectism
Latrodectism () is the illness caused by the bite of ''Latrodectus'' spiders (the black widow spider and related species). Pain, muscle rigidity, vomiting, and sweating are the symptoms of latrodectism. There are several spider species all named black widow: southern black widow spider (''L. mactans''), the European black widow (''L. tredecimguttatus''), Western black widow spider (''L. hesperus''), Northern black widow spider (''L. variolus''). Other ''Latrodectus'' that cause latrodectism are the Australian redback spider (''L. hasselti''), the New Zealand katipō spider (''L. katipo'') and the South American ''Latrodectus corallinus'' and ''Latrodectus curacaviensis''. Several other members of the genus ''Latrodectus'' are not commonly associated with latrodectism including the cosmopolitan brown widow (''L. geometricus''). Signs and symptoms Symptoms of a bite depend on the amount of venom injected. A bite of ''Latrodectus'' may not inject ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
