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Latrodectus Curacaviensis
''Latrodectus curacaviensis'' is a species of black widow spider, that belongs to the genus ''Latrodectus''. It is known as the South American black widow, Brazilian black widow or Araña del trigo. Description Like many black widow species, females are larger than males, growing up to 11–17 mm, with their body and legs black and red. Males are much smaller, known by their long legs, and white or brown color. ''Latrodectus curacaviensis'' is mainly nocturnal. It is not aggressive to humans, but females will attack to defend their egg sacs. It feeds on small insects. They have a distinct hourglass mark with a black diamond shape and four red triangles in a square. Bites are rare but dangerous. Distribution and habitat It has been reported in the Lesser Antilles and South America. It is usually found under logs, in sheds, stone fireplaces, near trash and debris. Venom The venom contains excitatory neurotoxins ( alpha-latrotoxins). Bites usually deliver only small amou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus comes above species and below family (taxonomy), family. In binomial nomenclature, the genus name forms the first part of the binomial species name for each species within the genus. :E.g. ''Panthera leo'' (lion) and ''Panthera onca'' (jaguar) are two species within the genus ''Panthera''. ''Panthera'' is a genus within the family Felidae. The composition of a genus is determined by taxonomy (biology), taxonomists. The standards for genus classification are not strictly codified, so different authorities often produce different classifications for genera. There are some general practices used, however, including the idea that a newly defined genus should fulfill these three criteria to be descriptively useful: # monophyly – all descendants ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. 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] |
Latrotoxin
A latrotoxin is a high-molecular mass neurotoxin found in the venom of spiders of the genus ''Latrodectus'' (widow spiders) as well as at least one species of another genus in the same family, '' Steatoda nobilis''. Latrotoxins are the main active components of the venom and are responsible for the symptoms of latrodectism. The following latrotoxins have been described: five insecticidal toxins, termed α, β, γ, δ and ε-latroinsectotoxins, one vertebrate-specific neurotoxin, alpha-latrotoxin, and one toxin affecting crustaceans, α-latrocrustatoxin. α-Latrotoxin The best-studied latrotoxin is alpha-latrotoxin, which acts presynaptically to release neurotransmitters (including acetylcholine) from sensory and motor neurons, as well as on endocrine cells (to release insulin, for example). It is a ~130 kDa protein that exists mainly in its dimerized or tetramerized forms. α-Latrotoxin (α-LTX) can naturally be found in widow spiders of the genus ''Latrodectus''. The most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amazonas (Brazilian State)
Amazonas () is a state of Brazil, located in the North Region in the northwestern corner of the country. It is the largest Brazilian state by area and the 9th largest country subdivision in the world, and the largest in South America, being greater than the areas of Uruguay, Paraguay, and Chile combined. Mostly located in the Southern Hemisphere, it is the third largest country subdivision in the Southern Hemisphere after the Australian states of Western Australia and Queensland. Entirely in the Western Hemisphere, it is the fourth largest in the Western Hemisphere after Greenland, Nunavut and Alaska. It would be the sixteenth largest country in land area, slightly larger than Mongolia. Neighbouring states are (from the north clockwise) Roraima, Pará, Mato Grosso, Rondônia, and Acre. It also borders the nations of Peru, Colombia and Venezuela. This includes the Departments of Amazonas, Vaupés and Guainía in Colombia, as well as the Amazonas state in Venezuela, and ... [...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] |
Spiders Of South America
Spiders ( order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had a separate t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spiders Described In 1776
Spiders (order Araneae) are air-breathing arthropods that have eight legs, chelicerae with fangs generally able to inject venom, and spinnerets that extrude silk. They are the largest order of arachnids and rank seventh in total species diversity among all orders of organisms. Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every land habitat. , 50,356 spider species in 132 families have been recorded by taxonomists. However, there has been debate among scientists about how families should be classified, with over 20 different classifications proposed since 1900. Anatomically, spiders (as with all arachnids) differ from other arthropods in that the usual body segments are fused into two tagmata, the cephalothorax or prosoma, and the opisthosoma, or abdomen, and joined by a small, cylindrical pedicel, however, as there is currently neither paleontological nor embryological evidence that spiders ever had a separate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
