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Ordgarius Sexspinosus
''Ordgarius sexspinosus'' is a species of spider in the orb-weaver spider family Araneidae, found from India to Japan and Indonesia. ''O. sexspinosus'' is a bolas spider. Rather than using a web, adult females catch their prey by using a line with one or two sticky drops (a "bolas") which they swing. Description The adult female of ''Ordgarius sexspinosus'' has a body length of about 7–10 mm. The carapace is about 3.6–3.7 mm long. It is dark brown and has six projections (tubercules). Two are arranged in the centre of the cephalic (head) part of the cephalothorax, the larger behind the smaller. Four are arranged in a transverse row in the thoracic part, two projecting forwards and two slightly behind projecting sideways. The legs are yellowish brown with brown rings. The first leg is the longest. The abdomen is usually longer (up to 6.9 mm) than wide. The upper surface is grayish brown with complicated white patterns. The "shoulders" of the abdomen are hu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tamerlan Thorell
Tord Tamerlan Teodor Thorell (3 May 1830 – 22 December 1901) was a Sweden, Swedish arachnologist. Thorell studied spiders with Giacomo Doria at the Museo Civico di Storia Naturale de Genoa. He corresponded with other arachnologists, such as Octavius Pickard-Cambridge, Eugène Simon and Thomas Workman (entomologist), Thomas Workman. He described more than 1,000 spider species during his time from the 1850 to 1900. Thorell wrote: ''On European Spiders'' (1869) and ''Synonym of European Spiders'' (1870-73). Taxonomic honors The Orb-weaver spider genus ''Thorellina'' and the jumping spider genus ''Thorelliola'' are named after him, as well as about 30 species of spiders: * ''Araneus thorelli'' (Roewer, 1942) (Myanmar) (Araneidae) * ''Gasteracantha thorelli'' Keyserling, 1864 (Madagascar) (Araneidae) * ''Leviellus thorelli'' (Ausserer, 1871) (Europe) (Araneidae) * ''Mandjelia thorelli'' (Raven, 1990) (Queensland) (Barychelidae) * ''Clubiona thorelli'' Roewer, 1951 (Sumatra) (Clubi ... [...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] |
Spider
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orb-weaver Spider
Orb-weaver spiders are members of the spider family Araneidae. They are the most common group of builders of spiral wheel-shaped webs often found in gardens, fields, and forests. The English word "orb" can mean "circular", hence the English name of the group. Araneids have eight similar eyes, hairy or spiny legs, and no stridulating organs. The family has a cosmopolitan distribution, including many well-known large or brightly colored garden spiders. With 3,108 species in 186 genera worldwide, the Araneidae comprise the third-largest family of spiders (behind the Salticidae and Linyphiidae). Araneid webs are constructed in a stereotypical fashion, where a framework of nonsticky silk is built up before the spider adds a final spiral of silk covered in sticky droplets. Orb webs are also produced by members of other spider families. The long-jawed orb weavers (Tetragnathidae) were formerly included in the Araneidae; they are closely related, being part of the superfamily Arane ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolas Spider
A bolas spider is a member of the orb-weaver spider (family Araneidae) that, instead of spinning a typical orb web, hunts by using one or more sticky "capture blobs" on the end of a silk line, known as a "bolas". By swinging the bolas at flying male moths or moth flies nearby, the spider may snag its prey rather like a fisherman snagging a fish on a hook. Because of this, they are also called angling or fishing spiders (although the remotely related genus ''Dolomedes'' is also called a fishing spider). The prey is lured to the spider by the production of up to three sex pheromone-analogues. Bolas spiders have been treated as either the whole or part of either the tribe "Mastophoreae" or Mastophorini, the subfamily Mastophorinae, or the informal group mastophorines. Recent studies show that the genus ''Celaenia'', which does not use a bolas, belongs in the same taxonomic group. Description Bolas spiders are small nocturnal animals with conspicuous outgrowths on the upper (dorsa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bolas
Bolas or bolases (singular bola; from Spanish and Portuguese ''bola'', "ball", also known as a ''boleadora'' or ''boleadeira'') is a type of throwing weapon made of weights on the ends of interconnected cords, used to capture animals by entangling their legs. Bolas were most famously used by the gauchos, but have been found in excavations of Pre-Columbian settlements, especially in Patagonia, where indigenous peoples (particularly the Tehuelche) used them to catch 200-pound guanacos and rheas. The Mapuche and the Inca army used them in battle. Mapuche warriors used bolas in their confrontations with the Chilean Army during the Occupation of AraucanÃa (1861–1883). Use ''Gauchos'' used ''boleadoras'' to capture running cattle or game. Depending on the exact design, the thrower grasps the ''boleadora'' by one of the weights or by the nexus of the cords. The thrower gives the balls momentum by swinging them and then releases the ''boleadora''. The weapon is usually used t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glossary Of Spider Terms
This glossary describes the terms used in formal descriptions of spiders; where applicable these terms are used in describing other arachnids. Links within the glossary are shown . Terms A Abdomen or opisthosoma: One of the two main body parts ( tagmata), located towards the posterior end; see also Abdomen § Other animals Accessory claw: Modified at the tip of the in web-building spiders; used with to grip strands of the web Anal tubercle: A small protuberance (tubercule) above the through which the anus opens Apodeme → Apophysis (plural apophyses): An outgrowth or process changing the general shape of a body part, particularly the appendages; often used in describing the male → Atrium (plural atria): An internal chamber at the entrance to the in female haplogyne spiders B Bidentate: Having two Book lungs: Respiratory organs on the ventral side (underside) of the , in front of the , opening through narrow slits; see also Book lungs Branchial operculum â ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Palpal Bulb
The two palpal bulbs – also known as palpal organs and genital bulbs – are the copulatory organs of a male spider. They are borne on the last segment of the pedipalps (the front "limbs" of a spider), giving the spider an appearance often described as like wearing boxing gloves. The palpal bulb does not actually produce sperm, being used only to transfer it to the female. Palpal bulbs are only fully developed in adult male spiders and are not completely visible until after the final moult. In the majority of species of spider, the bulbs have complex shapes and are important in identification. Structure The palpal bulb of a mature male spider is borne on the last segment of the pedipalp. This segment usually has touch-sensitive hairs (setae) with nerves leading to them. The bulb itself is entirely without nerves, and hence without sensory organs and muscles, since these depend on nerves for their functioning, although some spiders have one or two muscles external to the bulb and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eugène Simon
Eugène Louis Simon (; 30 April 1848 – 17 November 1924) was a French naturalist who worked particularly on insects and spiders, but also on birds and plants. He is by far the most prolific spider taxonomist in history, describing over 4,000 species. Work on spiders His most significant work was ''Histoire Naturelle des Araignées'' (1892–1903), an encyclopedic treatment of the spider genera of the world. It was published in two volumes of more than 1000 pages each, and the same number of drawings by Simon. Working at the Muséum National d'Histoire Naturelle in Paris, it took Simon 11 years to complete, while working at the same time on devising a taxonomic scheme that embraced the known taxa. Simon described a total of 4,650 species, and as of 2013 about 3,790 species are still considered valid. The International Society of Arachnology offers a Simon Award recognising lifetime achievement. The Eocene fossil spider species '' Cenotextricella simoni'' was named in his ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyrtarachninae
Cyrtarachninae is a subfamily of spiders in the family Araneidae (orb-weaver spiders, araneids). The group has been circumscribed in several different ways. It originated as the group Cyrtarachneae, described by Eugène Simon in 1892. The group was later treated at different ranks: as a tribe, both under Simon's name and as Cyrtarachnini, and as the subfamily Cyrtarachninae. Circumscriptions have varied. The broadest circumscription, Cyrtarachninae ''sensu lato'' (''s.l.''), includes three of Simon's original groups, including the bolas spiders (also placed in the tribe Mastophoreae or Mastophorini, or in the subfamily Mastophorinae). Unlike most araneids, members of the subfamily do not construct orb webs, some not using webs at all to capture prey, some using one or more sticky drops on a single line (a bolas), while others construct webs with few widely spaced non-spiral threads, some triangular. Many have been shown to attract prey by producing analogues of insect sex pheromon ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Phylogenetics
Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to determine the processes by which diversity among species has been achieved. The result of a molecular phylogenetic analysis is expressed in a phylogenetic tree. Molecular phylogenetics is one aspect of molecular systematics, a broader term that also includes the use of molecular data in taxonomy and biogeography. Molecular phylogenetics and molecular evolution correlate. Molecular evolution is the process of selective changes (mutations) at a molecular level (genes, proteins, etc.) throughout various branches in the tree of life (evolution). Molecular phylogenetics makes inferences of the evolutionary relationships that arise due to molecular evolution and results in the construction of a phylogenetic tree. History The theoretical frame ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sex Pheromone
Sex pheromones are pheromones released by an organism to attract an individual of the same species, encourage them to mate with them, or perform some other function closely related with sexual reproduction. Sex pheromones specifically focus on indicating females for breeding, attracting the opposite sex, and conveying information on species, age, sex and genotype. Non-volatile pheromones, or cuticular contact pheromones, are more closely related to social insects as they are usually detected by direct contact with chemoreceptors on the antennae or feet of insects. Insect sex pheromones have found uses in pheromone trap , monitoring and trapping of pest insects. Evolution Sex pheromones have evolved in many species. The many types of pheromones (i.e. alarm, aggregation, defense, sexual attraction) all have a common cause acting as chemical cues to trigger a response. However, sex pheromones are particularly associated with signaling mating behaviors or dominance. The odors release ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
