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Theridion Attritum
''Theridion attritum'' is a spider from Western Australia. While it was formerly placed in the families Araneidae and Theridiosomatidae' in 1967 it was found to belong to the family Theridiidae, and indeed to the genus ''Theridion''. While all members of the first two families have a large colulus, while ''T. attritum'' lacks one altogether. It is not to be confused with '' Anelosimus attritus'', which was for a time known as ''Theridion attritum''.Levi 1967 Description ''Theridion attritum'' is 2.2mm long. It has a yellowish carapace with a black line all around. The sternum is yellow-orange with gray pigment, the legs are yellow with darker marks. The top of the abdomen is whitish with a median darker longitudinal band, irregular in outline and bordered on each side by a white band. The venter is black with a white transverse pigment band. The species is surprisingly similar to '' Theridion melanurum'' and ''Theridion varians ''Theridion varians'' is a species of cobweb spi ... [...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] |
Western Australia
Western Australia (commonly abbreviated as WA) is a state of Australia occupying the western percent of the land area of Australia excluding external territories. It is bounded by the Indian Ocean to the north and west, the Southern Ocean to the south, the Northern Territory to the north-east, and South Australia to the south-east. Western Australia is Australia's largest state, with a total land area of . It is the second-largest country subdivision in the world, surpassed only by Russia's Sakha Republic. the state has 2.76 million inhabitants percent of the national total. The vast majority (92 percent) live in the south-west corner; 79 percent of the population lives in the Perth area, leaving the remainder of the state sparsely populated. The first Europeans to visit Western Australia belonged to the Dutch Dirk Hartog expedition, who visited the Western Australian coast in 1616. The first permanent European colony of Western Australia occurred following the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Araneidae
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 Araneo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theridiosomatidae
The ray spiders (Theridiosomatidae) are a family of spiders first described by Eugène Simon in 1881. They are most recognizable for their construction of cone-shaped webs. The family contains several genera which actively hunt for prey by using their webs to slingshot themselves towards prey. Genera , the World Spider Catalog accepts the following genera: *'' Andasta'' Simon, 1895 – Seychelles, Malaysia, Sri Lanka *'' Baalzebub'' Coddington, 1986 – Central America, Brazil, Australia, China *'' Chthonopes'' Wunderlich, 2011 – Laos *'' Chthonos'' Coddington, 1986 – Ecuador, Brazil, Peru *'' Coddingtonia'' Miller, Griswold & Yin, 2009 – Malaysia, Laos *'' Cuacuba'' Prete, Cizauskas & Brescovit, 2018 *'' Epeirotypus'' O. Pickard-Cambridge, 1894 – Mexico, Costa Rica *'' Epilineutes'' Coddington, 1986 – Mexico, Brazil *'' Karstia'' Chen, 2010 – China *'' Menglunia'' Zhao & Li, 2012 – China *'' Naatlo'' Coddington, 1986 – Central America, South America, Trinidad and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theridiidae
Theridiidae, also known as the tangle-web spiders, cobweb spiders and comb-footed spiders, is a large family of Araneomorphae, araneomorph spiders first described by Carl Jakob Sundevall in 1833. This diverse, globally distributed family includes over 3,000 species in 124 genus, genera, and is the most common arthropod found in human dwellings throughout the world. Theridiid spiders are both Entelegynae, entelegyne, meaning that the females have a genital plate, and Cribellum, ecribellate, meaning that they spin sticky capture silk instead of woolly silk. They have a comb of serrated bristles (setae) on the Arthropod leg, tarsus of the fourth leg. The family includes some model organisms for research, including the List of medically significant spider bites, medically important Latrodectus, widow spiders. They are important to studies characterizing their venom and its clinical manifestation, but widow spiders are also used in research on spider silk and sexual biology, including ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colulus
Cribellum literally means "little sieve", and in biology the term generally applies to anatomical structures in the form of tiny perforated plates. In certain groups of diatoms it refers to microscopically punctured regions of the frustule, or outer layer. In certain groups of spider species, so-called cribellate spiders, the cribellum is a silk spinning organ. Unlike the usual spinnerets of spiders, the cribellum consists of one or more plates covered in thousands of tiny spigots, tiny holes that hardly project from the surface, in contrast to the elongated spigots that project from spinnerets. These minute spigots produce extremely fine fibers, merely tens of nanometres thick, which are combed out by the spider's calamistrum, producing silk with a woolly texture. The fibers are so small in diameter that they are strongly subject to Van der Waals forces. In addition, the fibres have a surface that absorbs waxes from the epicuticle of insect prey on contact. This creates a pow ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anelosimus Attritus
''Anelosimus'' is a cosmopolitan genus of cobweb spiders (Theridiidae), currently containing 74 species. ''Anelosimus'' is a key group in the study of sociality and its evolution in spiders (Aviles 1997). It contains species spanning the spectrum from solitary to highly social (quasisocial), with eight quasisocial species, far more than any other spider genus. Among these is the South American social species '' Anelosimus eximius'', among the best studied social spider species. The web of a colony of ''A. eximius'' can reach cover entire tree canopies and contain tens of thousands of individuals. Most of the highly social species live in lowland tropical forests, and all occur in the Americas. Other species, particularly those at higher altitudes in northern latitudes in the Americas and all non-American species appear to be solitary or sub-social. Social ''Anelosimus'' species are generally highly inbred and have female-biased sex ratios, with up to 10 females per male. The soc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theridion
''Theridion'' is a genus of tangle-web spiders with a worldwide distribution. Notable species are the Hawaiian happy face spider (''T. grallator''), named for the iconic symbol on its abdomen, and '' T. nigroannulatum'', one of few spider species that lives in social groups, attacking prey en masse to overwhelm them as a team. Identification Spiders in this genus are about as long or longer then they are wide. Their chelicerae have two or less teeth on the front edge and none on the back edge. The front leg is the longest in both genders, but the next longest is the second leg in males and the fourth leg in females. The epigyne can vary, but the pedipalp has a median apophysis and a colulus is absent from both genders. In several species, the males have mastidia (projections) on the chelicerae. ''Theridion'' has the anterior eye row slightly curved and with a gap between it and the posterior eye row. This distinguishes it from '' Enoplognatha'', another theridiid ge ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carapace
A carapace is a Dorsum (biology), dorsal (upper) section of the exoskeleton or shell in a number of animal groups, including arthropods, such as crustaceans and arachnids, as well as vertebrates, such as turtles and tortoises. In turtles and tortoises, the underside is called the plastron. Crustaceans In crustaceans, the carapace functions as a protective cover over the cephalothorax (i.e., the fused head and thorax, as distinct from the abdomen behind). Where it projects forward beyond the eyes, this projection is called a rostrum (anatomy), rostrum. The carapace is Calcification, calcified to varying degrees in different crustaceans. Zooplankton within the phylum Crustacea also have a carapace. These include Cladocera, ostracods, and Isopoda, isopods, but isopods only have a developed "cephalic shield" carapace covering the head. Arachnids In arachnids, the carapace is formed by the fusion of prosomal tergites into a single Plate (animal anatomy), plate which carries the e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sternum (arthropod Anatomy)
The sternum (pl. "sterna") is the ventral portion of a segment of an arthropod thorax or abdomen. In insects, the sterna are usually single, large sclerites, and external. However, they can sometimes be divided in two or more, in which case the subunits are called sternites, and may also be modified on the terminal abdominal segments so as to form part of the functional genitalia, in which case they are frequently reduced in size and development, and may become internalized and/or membranous. For a detailed explanation of the terminology, see Kinorhynchs have tergal and sternal plates too, though seemingly not homologous with those of arthropods.Sørensen, M. V. et al. Phylogeny of Kinorhyncha based on morphology and two molecular loci. PLoS One 10, 1–33 (2015). Ventrites are externally visible sternites. Usually the first sternite is covered up, so that vertrite numbers do not correspond to sternid numbers. The term is also used in other arthropod groups such as crustaceans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Abdomen
The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso. The area occupied by the abdomen is called the abdominal cavity. In arthropods it is the posterior (anatomy), posterior tagma (biology), tagma of the body; it follows the thorax or cephalothorax. In humans, the abdomen stretches from the thorax at the thoracic diaphragm to the pelvis at the pelvic brim. The pelvic brim stretches from the lumbosacral joint (the intervertebral disc between Lumbar vertebrae, L5 and Vertebra#Sacrum, S1) to the pubic symphysis and is the edge of the pelvic inlet. The space above this inlet and under the thoracic diaphragm is termed the abdominal cavity. The boundary of the abdominal cavity is the abdominal wall in the front and the peritoneal surface at the rear. In vertebrates, the abdomen is a large body c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Theridion Melanurum
''Theridion melanurum'' is a species of cobweb spider in the family Theridiidae Theridiidae, also known as the tangle-web spiders, cobweb spiders and comb-footed spiders, is a large family of Araneomorphae, araneomorph spiders first described by Carl Jakob Sundevall in 1833. This diverse, globally distributed family includes .... It is found in a range from Europe to Siberia, Macaronesia, North Africa, Middle East, and has been introduced into the United States. References Theridiidae Articles created by Qbugbot Spiders described in 1831 {{theridiidae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
