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Portia Africana
''Portia africana'' is a jumping spider (family (biology), family Salticidae) found in Angola, Cameroon, the Central African Republic, Gabon, Ghana, the Ivory Coast, Sierra Leone, Zaire and Zambia. Its conspicuous main eyes provide vision more acute than a cat's during the day and 10 times more acute than a dragonfly, dragonfly's, and this is essential in ''P. africana''′s navigation, hunting and mating. Like other species of the genus ''Portia (spider), Portia'', ''P. africana'' prefers to hunt web-based spiders, jumping spiders and other types in that order. When hunting web-based spiders, ''Portia''s use trial and error to find a way to mislead the prey until the ''Portia'' is in a position to bite the victim. While other ''Portia''s live and hunt as individuals, ''P. africana'' forms large populations both in savanna areas and in the dense "cities" which social jumping spiders build in vegetation near the shoreline of lakes. In the savanna, groups of ''P. africana'', ge ... [...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] |
Savanna
A savanna or savannah is a mixed woodland-grassland (i.e. grassy woodland) ecosystem characterised by the trees being sufficiently widely spaced so that the canopy does not close. The open canopy allows sufficient light to reach the ground to support an unbroken herbaceous layer consisting primarily of grasses. According to '' Britannica'', there exists four savanna forms; ''savanna woodland'' where trees and shrubs form a light canopy, ''tree savanna'' with scattered trees and shrubs, ''shrub savanna'' with distributed shrubs, and ''grass savanna'' where trees and shrubs are mostly nonexistent.Smith, Jeremy M.B.. "savanna". Encyclopedia Britannica, 5 Sep. 2016, https://www.britannica.com/science/savanna/Environment. Accessed 17 September 2022. Savannas maintain an open canopy despite a high tree density. It is often believed that savannas feature widely spaced, scattered trees. However, in many savannas, tree densities are higher and trees are more regularly spaced than in for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spartaeinae
The Spartaeinae are a subfamily of the spider family Salticidae (jumping spiders). The subfamily was established by Fred R. Wanless in 1984 to include the groups Boetheae, Cocaleae, Lineae, Codeteae and Cyrbeae, which in turn were defined by Eugène Simon. The Spartaeinae are palaeotropical, with an exceptional diversity in the Malaysian and Indonesian archipelagos. They are unusual salticids that are considered basal to the phylogenetic tree of jumping spiders. Like the Lyssomaninae they lack many derived features that the Salticinae possess. Spartaeinae usually have large posterior median eyes. However, these were reduced in the genera ''Cyrba'', ''Gelotia'' and ''Wanlessia''. Genera In 2015, Spartaeinae was divided into three tribes with 29 genera. One has been added since. Tribe Cocalodini * '' Allococalodes'' Wanless, 1982 * '' Cocalodes'' Pocock, 1897 * '' Cucudeta'' Maddison, 2009 * '' Depreissia'' Lessert, 1942 * '' Tabuina'' Maddison, 2009 * '' Yamangalea'' Madd ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ultraviolet
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than X-rays. UV radiation is present in sunlight, and constitutes about 10% of the total electromagnetic radiation output from the Sun. It is also produced by electric arcs and specialized lights, such as mercury-vapor lamps, tanning lamps, and black lights. Although long-wavelength ultraviolet is not considered an ionizing radiation because its photons lack the energy to ionization, ionize atoms, it can cause chemical reactions and causes many substances to glow or fluorescence, fluoresce. Consequently, the chemical and biological effects of UV are greater than simple heating effects, and many practical applications of UV radiation derive from its interactions with organic molecules. Short-wave ultraviolet light damages DNA and sterilizes surf ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jumping Spider Eyes Layout 2
Jumping or leaping is a form of locomotion or movement in which an organism or non-living (e.g., robotic) mechanical system propels itself through the air along a ballistic trajectory. Jumping can be distinguished from running, galloping and other gaits where the entire body is temporarily airborne, by the relatively long duration of the aerial phase and high angle of initial launch. Some animals, such as the kangaroo, employ jumping (commonly called ''hopping'' in this instance) as their primary form of locomotion, while others, such as frogs, use it only as a means to escape predators. Jumping is also a key feature of various activities and sports, including the long jump, high jump and show jumping. Physics All jumping involves the application of force against a substrate, which in turn generates a reactive force that propels the jumper away from the substrate. Any solid or liquid capable of producing an opposing force can serve as a substrate, including ground or wate ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Euphorbia
''Euphorbia'' is a very large and diverse genus of flowering plants, commonly called spurge, in the family Euphorbiaceae. "Euphorbia" is sometimes used in ordinary English to collectively refer to all members of Euphorbiaceae (in deference to the type genus), not just to members of the genus. Euphorbias range from tiny annual plants to large and long-lived trees. The genus has roughly 2,000 members, making it one of the largest genera of flowering plants. It also has one of the largest ranges of chromosome counts, along with ''Rumex'' and ''Senecio''. ''Euphorbia antiquorum'' is the type species for the genus ''Euphorbia''. It was first described by Carl Linnaeus in 1753 in ''Species Plantarum''. Some euphorbias are widely available commercially, such as poinsettias at Christmas. Some are commonly cultivated as ornamentals, or collected and highly valued for the aesthetic appearance of their unique floral structures, such as the crown of thorns plant (''Euphorbia milii''). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sisal
Sisal (, ) (''Agave sisalana'') is a species of flowering plant native to southern Mexico, but widely cultivated and naturalized in many other countries. It yields a stiff fibre used in making rope and various other products. The term sisal may refer either to the plant's common name or the fibre, depending on the context. The sisal fibre is traditionally used for rope and twine, and has many other uses, including paper, cloth, footwear, hats, bags, carpets, geotextiles, and dartboards. It is also used as fibre reinforcements for composite fibreglass, rubber, and concrete products. Taxonomy The native origin of ''Agave sisalana'' is uncertain. Traditionally, it was deemed to be a native of the Yucatán Peninsula, but no records exist of botanical collections from there. They were originally shipped from the Spanish colonial port of Sisal in Yucatán (thus the name). The Yucatán plantations now cultivate henequen (''Agave fourcroydes''). H.S. Gentry hypothesized a Chiapas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Equator
The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can also be used for any other celestial body that is roughly spherical. In spatial (3D) geometry, as applied in astronomy, the equator of a rotating spheroid (such as a planet) is the parallel (circle of latitude) at which latitude is defined to be 0°. It is an imaginary line on the spheroid, equidistant from its poles, dividing it into northern and southern hemispheres. In other words, it is the intersection of the spheroid with the plane perpendicular to its axis of rotation and midway between its geographical poles. On and near the equator (on Earth), noontime sunlight appears almost directly overhead (no more than about 23° from the zenith) every day, year-round. Consequently, the equator has a rather stable daytime temperature throug ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kisumi
Kisumu ( ) is the third-largest city in Kenya after the capital, Nairobi, and the coastal city of Mombasa (census 2019). It is the third-largest city after Kampala and Mwanza in the Lake Victoria Basin. Apart from being an important political city, it is one of the premier industrial and commercial centres in Kenya. The city is currently undergoing an urban rejuvenation of the downtown and lower town which includes modernizing the lake front, decongesting main streets, and making the streets pedestrian-friendly. Culturally, Kisumu serves as the center of the Luo people of East Africa. It was the most prominent urban centre in the pre-colonial, post-colonial, and modern era for natives of the Kavirondo region. It was briefly renamed to Port Florence before being reverted to its original name. The city serves as the capital of Kisumu County and was the immediate former capital of now defuct Nyanza Province. It is an important link in the trade route between Lake Vict ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kenya
) , national_anthem = "Ee Mungu Nguvu Yetu"() , image_map = , map_caption = , image_map2 = , capital = Nairobi , coordinates = , largest_city = Nairobi , official_languages = Constitution (2009) Art. 7 ational, official and other languages"(1) The national language of the Republic is Swahili. (2) The official languages of the Republic are Swahili and English. (3) The State shall–-–- (a) promote and protect the diversity of language of the people of Kenya; and (b) promote the development and use of indigenous languages, Kenyan Sign language, Braille and other communication formats and technologies accessible to persons with disabilities." , languages_type = National language , languages = Swahili , ethnic_groups = , ethnic_groups_year = 2019 census , religion = , religion_year = 2019 census , demonym = ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Olfactory
The sense of smell, or olfaction, is the special sense through which smells (or odors) are perceived. The sense of smell has many functions, including detecting desirable foods, hazards, and pheromones, and plays a role in taste. In humans, it occurs when an odor binds to a receptor within the nasal cavity, transmitting a signal through the olfactory system. Glomeruli aggregate signals from these receptors and transmit them to the olfactory bulb, where the sensory input will start to interact with parts of the brain responsible for smell identification, memory, and emotion. There are many different causes for alteration, lack, or disturbance to a normal sense of smell, and can include damage to the nose or smell receptors, or central problems affecting the brain. Some causes include upper respiratory infections, traumatic brain injury, and neurodegenerative disease. History of study Early scientific study of the sense of smell includes the extensive doctoral dissertation of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pedipalp
Pedipalps (commonly shortened to palps or palpi) are the second pair of appendages of chelicerates – a group of arthropods including spiders, scorpions, horseshoe crabs, and sea spiders. The pedipalps are lateral to the chelicerae ("jaws") and anterior to the first pair of walking legs. Overview Pedipalps are composed of six segments or articles: the coxa, the trochanter, the femur, the short patella, the tibia, and the tarsus. In spiders, the coxae frequently have extensions called maxillae or gnathobases, which function as mouth parts with or without some contribution from the coxae of the anterior legs. The limbs themselves may be simple tactile organs outwardly resembling the legs, as in spiders, or chelate weapons ( pincers) of great size, as in scorpions. The pedipalps of Solifugae are covered in setae, but have not been studied in detail. Comparative studies of pedipalpal morphology may suggest that leg-like pedipalps are primitive in arachnids. At present, the only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
