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Loxosceles
The recluse spiders (''Loxosceles'' (), also known as brown spiders, fiddle-backs, violin spiders, and reapers, is a genus of spiders that was first described by R. T. Lowe in 1832. They are venomous spiders known for their bite, which sometimes produces a characteristic set of symptoms known as loxoscelism. Recluse spiders are now identified as members of the family Sicariidae, having formerly been placed in their own family, the Loxoscelidae. Although recluse spiders are feared, they are usually not aggressive. Relation with other spiders Sicariidae are of the superfamily Scytodoidea. Other families in the Scytodoidea include Drymusidae, Scytodidae, and Periegopidae. Habitat and appearance ''Loxosceles'' is distributed nearly worldwide in warmer areas. All have six eyes arranged in three groups of two (dyads) and some are brownish with a darker brown characteristic violin marking on the cephalothorax. However, the "violin marking" cannot be used as a reliable way to identif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loxosceles Rufescens
The recluse spiders (''Loxosceles'' (), also known as brown spiders, fiddle-backs, violin spiders, and reapers, is a genus of spiders that was first described by R. T. Lowe in 1832. They are venomous spiders known for their bite, which sometimes produces a characteristic set of symptoms known as loxoscelism. Recluse spiders are now identified as members of the family Sicariidae, having formerly been placed in their own family, the Loxoscelidae. Although recluse spiders are feared, they are usually not aggressive. Relation with other spiders Sicariidae are of the superfamily Scytodoidea. Other families in the Scytodoidea include Drymusidae, Scytodidae, and Periegopidae. Habitat and appearance ''Loxosceles'' is distributed nearly worldwide in warmer areas. All have six eyes arranged in three groups of two (dyads) and some are brownish with a darker brown characteristic violin marking on the cephalothorax. However, the "violin marking" cannot be used as a reliable way to ide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loxosceles Eye Group
The recluse spiders (''Loxosceles'' (), also known as brown spiders, fiddle-backs, violin spiders, and reapers, is a genus of spiders that was first described by R. T. Lowe in 1832. They are venomous spiders known for their bite, which sometimes produces a characteristic set of symptoms known as loxoscelism. Recluse spiders are now identified as members of the family Sicariidae, having formerly been placed in their own family, the Loxoscelidae. Although recluse spiders are feared, they are usually not aggressive. Relation with other spiders Sicariidae are of the superfamily Scytodoidea. Other families in the Scytodoidea include Drymusidae, Scytodidae, and Periegopidae. Habitat and appearance ''Loxosceles'' is distributed nearly worldwide in warmer areas. All have six eyes arranged in three groups of two (dyads) and some are brownish with a darker brown characteristic violin marking on the cephalothorax. However, the "violin marking" cannot be used as a reliable way to ide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mediterranean Recluse Spider
The Mediterranean recluse spider (''Loxosceles rufescens'') is a species of spider that originated in the Mediterranean region as its name implies, but can now be found in many parts of the world and is listed as one of the most invasive spiders world-wide. Usually dwelling in caves, the spiders will also inhabit basements and tunnels. Their webs shelter their egg sacs, which hatch into young that molt as they grow. The spider hunts at night and eats species including silverfish and cockroaches, and they usually target smaller insects. Similar to other species in their genus, bites from ''L. rufescens'' can cause necrosis and, for some individuals, systemic damage due to the enzyme sphingomyelinase D. Pest control may be undertaken with similar strategies as used for the brown recluse spider. Characteristics ''L. rufescens'' is a cave dwelling arachnid that is nearly indistinguishable in appearance to ''Loxosceles reclusa'', the brown recluse spider. Individuals can be identifie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brown Recluse Spider
The brown recluse (''Loxosceles reclusa''), Sicariidae (formerly placed in a family "Loxoscelidae") is a recluse spider with necrotic venom. Similar to those of other recluse spiders, their bites sometimes require medical attention. The brown recluse is one of three spiders in North America with medically significant venom, the others being the black widow and the Chilean recluse. Brown recluse spiders are usually between , but may grow larger. While typically light to medium brown, they range in color from whitish to dark brown or blackish gray. The cephalothorax and abdomen are not necessarily the same color. These spiders usually have markings on the dorsal side of their cephalothorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider, resulting in the nicknames fiddleback spider, brown fiddler, or violin spider. Description The violin pattern is not a definitive identifier, as other spiders can have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Loxoscelism
Loxoscelism () is a condition occasionally produced by the bite of the recluse spiders (genus ''Loxosceles''). The area becomes dusky and a shallow open sore forms as the skin around the bite dies (necrosis). It is the only proven type of necrotic arachnidism in humans. While there is no known therapy effective for loxoscelism, there has been research on antibiotics, surgical timing, hyperbaric oxygen, potential antivenoms and vaccines. Because of the number of diseases that may mimic loxoscelism, it is frequently misdiagnosed by physicians. Loxoscelism was first described in the United States in 1879 in Tennessee. Although there are up to 13 different ''Loxosceles'' species in North America (11 native and two nonnative), ''Loxosceles reclusa'' is the species most often involved in serious envenomation. ''L. reclusa'' has a limited habitat that includes the Southeast United States. In South America, '' L. laeta'', '' L. intermedia'' (found in Brazil and Argentina), and '' L. ga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chilean Recluse Spider
The Chilean recluse spider, ''Loxosceles laeta'', is a highly venomous spider of the family Sicariidae. In Spanish, it (and other South American recluse spiders) is known as ', or "corner spider"; in Brazilian Portuguese, as ' or "brown spider". It is considered by many to be the most dangerous of recluse spiders, and its bites often result in serious systemic reactions, up to and including death. Description The Chilean recluse is one of the larger species of recluse spiders, generally ranging from 8–40 mm in size (including legs). Like most recluses, it is brown and usually has markings on the dorsal side of its thorax, with a black line coming from it that looks like a violin with the neck of the violin pointing to the rear of the spider resulting in the nickname "fiddleback spider" or "violin spider" in English-speaking areas. Coloring varies from light tan to brown and the violin marking may not be visible. Since the "violin pattern" is not diagnostic, it is far mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sicariidae
Sicariidae is a family of six-eyed venomous spiders known for their potentially necrotic bites. The family consists of three genera and about 160 species. Well known spiders in this family include the brown recluse spider and the six-eyed sand spider. Description ''Loxosceles'', commonly known as "recluse spiders" or "violin spiders", is distributed nearly worldwide in warmer areas. ''Hexophthalma'' and '' Sicarius'', commonly known as "sand spiders" or "assassin spiders", live in the deserts of southern Africa and South to Central America, respectively. They are known for their self-burying behavior and the ability to go for long periods without food or water. All members have six eyes arranged in three groups of two (dyads). Violin spiders are usually brownish with a darker brown characteristic violin marking on the cephalothorax. They are also haplogyne, meaning the females possessing unsclerotised genitals. ''Hexophthalma'' and ''Sicarius'' resemble crab spiders and lack ... [...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] |
Loxosceles Gaucho
''Loxosceles gaucho'' commonly known in English as the gaucho spider. is a highly venomous recluse spider endemic to South America. Description and behavior Adult females grow up to 7–12 mm, the maximum reported is 14 mm. They are mainly characterized by their brown color, leading to them be colloquially referred to as ''''Aranha marrom'''' (Portuguese for brown spider) in Brazil, the body is characterized by a pale to dark brown color (often reddish), with a dorsal violin-shaped mark, slightly darker on the carapace, with long and slender legs, without dark marks or stripes. Males have the thoracic region with the clearest impression, consisting of bands, with the anterior portion of the cephalothorax forming in the rear direction a '' V '' design, while pedipalps have the last short articles and curved stylus. Females have the anterior portion of the cephalothorax forming a '' U '' shape backwards. Like many recluse spiders, It is nocturnal, hunting preys such as i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sphingomyelinase D
Sphingomyelin phosphodiesterase D (EC 3.1.4.41, sphingomyelinase D) is an enzyme of the sphingomyelin phosphodiesterase family with systematic name sphingomyelin ceramide-phosphohydrolase. These enzymes catalyse the hydrolysis of sphingomyelin, resulting in the formation of ceramide 1-phosphate and choline: : sphingomyelin + H2O \rightleftharpoons ceramide 1-phosphate + choline or the hydrolysis of 2-lysophosphatidylcholine to give choline and 2-lysophosphatidate. Sphingomyelin phosphodiesterase D activity is shared by enzymes with a wider substrate range, classified as phospholipases D or lipophosphodiesterase II . Sphingomyelinases D are produced by some spiders in their venoms, specifically the brown recluse (''Loxosceles reclusa''), by arthropods such as ticks, or pathogenic bacteria and fungi. Pathogenicity is expressed through different mechanisms, such as membrane destabilization, cell penetration, inflammation of the lungs and cutaneous lesions, common following brown rec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hexophthalma
''Hexophthalma'' is a genus of spiders in the family Sicariidae. Although the genus was originally erected in 1878 (then with the name ''Hexomma''), it was merged into the genus '' Sicarius'' in the 1890s, and remained unused until revived in 2017, when it was discovered that the African species then placed in ''Sicarius'' were distinct. The English name six-eyed sand spiders is used for members of the genus, particularly ''Hexophthalma hahni''. Species in the genus have necrotic (dermonecrotic) venom, and can potentially cause serious or even life-threatening wounds. Taxonomy The genus was first created in 1878 by Friedrich Karsch as ''Hexomma'', with the sole species '' Hexomma hahni''. By 1879, though, Karsch had realized that this name had already been used in 1877 for a species of harvestman, so he published the replacement name ''Hexophthalma''. In 1893, Eugène Simon transferred ''Hexophthalma hahni'' to the genus '' Sicarius'', and ''Hexophthalma'' fell out of use, until ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cytotoxic
Cytotoxicity is the quality of being toxic to cells. Examples of toxic agents are an immune cell or some types of venom, e.g. from the puff adder (''Bitis arietans'') or brown recluse spider (''Loxosceles reclusa''). Cell physiology Treating cells with the cytotoxic compound can result in a variety of cell fates. The cells may undergo necrosis, in which they lose membrane integrity and die rapidly as a result of cell lysis. The cells can stop actively growing and dividing (a decrease in cell viability), or the cells can activate a genetic program of controlled cell death (apoptosis). Cells undergoing necrosis typically exhibit rapid swelling, lose membrane integrity, shut down metabolism, and release their contents into the environment. Cells that undergo rapid necrosis in vitro do not have sufficient time or energy to activate apoptotic machinery and will not express apoptotic markers. Apoptosis is characterized by well defined cytological and molecular events including a change i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
