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Spider Vision
The eyes of spiders vary significantly in their structure, arrangement, and function. They usually have eight, each being a simple eye with a single lens (optics), lens rather than multiple units as in the compound eyes of insects. The specific arrangement and structure of the eyes is one of the features used in the identification and classification of different species, genera, and families. Most Haplogynae, haplogynes have six eyes, although some have eight (Plectreuridae), four (e.g., ''Tetrablemma'') or even two (most Caponiidae). In some cave species, there are no eyes at all (e.g. Stalita taenaria). Sometimes one pair of eyes is better developed than the rest. Several families of hunting spiders, such as jumping spiders and wolf spiders, have fair to excellent vision. The main pair of eyes in jumping spiders even sees in colour. Structure and anatomy Spiders' eyes are Simple eye in invertebrates, simple eyes, or ''ocelli'' (singular ''ocellus''), meaning their eyes have a si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eye Arrangement Of A Hogna Wolf Spider
Eyes are organs of the visual system. They provide living organisms with vision, the ability to receive and process visual detail, as well as enabling several photo response functions that are independent of vision. Eyes detect light and convert it into electro-chemical impulses in neurons (neurones). In higher organisms, the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in molluscs, chordates and arthropods. The most simple eyes, pit eyes, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diagram Of Spider Canoe Eye
A diagram is a symbolic representation of information using visualization techniques. Diagrams have been used since prehistoric times on walls of caves, but became more prevalent during the Enlightenment. Sometimes, the technique uses a three-dimensional visualization which is then projected onto a two-dimensional surface. The word '' graph'' is sometimes used as a synonym for diagram. Overview The term "diagram" in its commonly used sense can have a general or specific meaning: * ''visual information device'' : Like the term "illustration", "diagram" is used as a collective term standing for the whole class of technical genres, including graphs, technical drawings and tables. * ''specific kind of visual display'' : This is the genre that shows qualitative data with shapes that are connected by lines, arrows, or other visual links. In science the term is used in both ways. For example, Anderson (1997) stated more generally: "diagrams are pictorial, yet abstract, representat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tarantula
Tarantulas comprise a group of large and often hairy spiders of the family Theraphosidae. , 1,040 species have been identified, with 156 genera. The term "tarantula" is usually used to describe members of the family Theraphosidae, although many other members of the same infraorder ( Mygalomorphae) are commonly referred to as "tarantulas" or "false tarantulas". Some of the more common species have become popular in the exotic pet trade. Many New World species kept as pets have setae known as urticating hairs that can cause irritation to the skin, and in extreme cases, cause damage to the eyes. Overview Like all arthropods, the tarantula is an invertebrate that relies on an exoskeleton for muscular support.Pomeroy, R. (2014, February 4). Pub. Real Clear Science, "Spiders, and Their Amazing Hydraulic Legs and Genitalia". Retrieved October 13, 2019, from https://www.realclearscience.com/blog/2013/02/spiders-their-amazing-hydraulic-legs-and-genitals.html. Like other Arachn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drassodes Cupreus
''Drassodes cupreus'' is a species of spider in the genus ''Drassodes'', family Gnaphosidae. A ground-living nocturnal hunter, it spends the day in a silken retreat. Description Females are 10–18 mm, males 10–13 mm. The carapace (the upper surface of the prosoma) is brownish with a darker border. The abdomen (opisthosoma) is hairy and similarly coloured. The posterior median eyes are closely spaced. In general appearance, ''D. cupreus'' cannot be distinguished from other ''Drassodes'' species, such as ''Drassodes lapidosus''. Identification relies on the shape of the epigyne in the female, and the arrangement of the teeth on the chelicerae and shape of the palpal bulb in the male. Like other species of ''Drassodes'', ''Drassodes cupreus'' is a nocturnal hunter, spending the day in a silken retreat. Mature females are found throughout the year, mature males only in spring and summer. Taxonomy ''Drassodes cupreus'' was first described by John Blackwall in 1834, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nursery Web Spider
Nursery web spiders (Pisauridae) is a family of araneomorph spiders first described by Eugène Simon in 1890. They resemble wolf spiders (Lycosidae) except for several key differences. Wolf spiders have two very prominent eyes in addition to the other six, while a nursery web spider's eyes are all about the same size. Additionally, female nursery web spiders carry their egg sacs with their jaws and pedipalps instead of attaching them to their spinnerets as wolf spiders do. When the eggs are about to hatch, a female spider builds a nursery "tent", places her egg sac inside, and stands guard outside, hence the family's common name. Like the wolf spiders, however, the nursery web spiders are roaming hunters that don't use webs for catching prey. Species occur throughout the world except for extremely dry or cold environments, and are common just about everywhere. Many can walk on the surface of still bodies of water and may even dive beneath the surface temporarily to escape enemies. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deinopidae
Deinopidae, also known as net casting spiders, is a family of cribellate spiders first described by Carl Ludwig Koch in 1850. It consists of stick-like elongated spiders that catch prey by stretching a web across their front legs before propelling themselves forward. These unusual webs will stretch two or three times their relaxed size, entangling any prey that touch them. The posterior median eyes have excellent night vision, allowing them to cast nets accurately in low-light conditions. These eyes are larger than the others, and sometimes makes these spiders appear to only have two eyes. Ogre-faced spiders ('' Deinopis'') are the best known genus in this family. The name refers to the perceived physical similarity to the mythological creature of the same name. This family also includes the humped-back spiders (''Menneus''). They are distributed through tropics worldwide from Australia to Africa and the Americas. In Florida, ''Deinopis'' often hangs upside down from a silk l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fishing Spider
''Dolomedes'' is a genus of large spiders of the family Pisauridae. They are also known as fishing spiders, raft spiders, dock spiders or wharf spiders. Almost all ''Dolomedes'' species are semiaquatic, with the exception of the tree-dwelling '' D. albineus'' of the southeastern United States. Many species have a striking pale stripe down each side of the body. They hunt by waiting at the edge of a pool or stream, then when they detect the ripples from prey, they run across the surface to subdue it using their foremost legs, which are tipped with small claws; like other spiders they then inject venom with their hollow jaws to kill and digest the prey. They mainly eat insects, but some larger species are able to catch small fish. They can also climb beneath the water, when they become encased in a silvery film of air. "''Dolomedes''" is derived from the Greek word "δολομήδης" which means wily, deceitful. There are over a hundred species of ''Dolomedes'' throughout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amaurobiidae
''Amaurobiidae'' is a family of three-clawed cribellate or ecribellate spiders found in crevices and hollows or under stones where they build retreats, and are often collected in pitfall traps. Unlidded burrows are sometimes quite obvious in crusty, loamy soil. They are difficult to distinguish from related spiders in other families, especially Agelenidae, Desidae and Amphinectidae. Their intra- and interfamilial relationships are contentious. According to the World Spider Catalog, 2019, the family Amaurobiidae includes about 275 species in 49 genera. In Australia, they are small to medium-sized entelegyne spiders with minimal sheet webs. They are fairly common in Tasmania and nearby mainland Australia in cooler rainforest, some in caves. They are widespread but uncommon along the eastern coastline. They generally have eight similar eyes in two conservatively curved rows. They often have a calamistrum on metatarsus IV associated with a cribellum. Australian amaurobiids may ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clubionidae
The sac spiders of the family Clubionidae have a very confusing taxonomic history. Once, this family was a large catch-all taxon for a disparate collection of spiders, similar only in that they had eight eyes arranged in two rows and conical anterior spinnerets that touched, and were wandering predators that built silken retreats, or sacs, usually on plant terminals, between leaves, under bark, or under rocks. These are now recognized to include several families, some of which are more closely related to the three-clawed spiders, like lynx and wolf spiders, than to Clubionidae and related families.Tree of Life Web Project. 2006. Clubionidae. Version 25 March 2006 (temporary). http://tolweb.org/Clubionidae/2675/2006.03.25 in The Tree of Life Web Project, http://tolweb.org/ General The remnant Clubionidae now consist of a few over 500 species in 15 genera worldwide. However, "sac spider" used on its own should imply a member of the family Clubionidae, but other common names may us ... [...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] |
Mygalomorphae
The Mygalomorphae, or mygalomorphs, are an infraorder of spiders, and comprise one of three major groups of living spiders with over 3000 species, found on all continents except Antarctica. Many members are known as trapdoor spiders due to them forming trapdoors over their burrows. Other prominent groups include Australian funnel web spiders and tarantulas, with the latter accounting for around one third of all mygalomorphs. Description This group of spiders comprises mostly heavy-bodied, stout-legged spiders including tarantulas, Australian funnel-web spiders, mouse spiders, and various families of spiders commonly called trapdoor spiders. Like the "primitive" suborder of spiders Mesothelae, they have two pairs of book lungs, and downward-pointing chelicerae. Because of this, the two groups were once believed to be closely related. Later it was realized that the common ancestors of all spiders had these features (a state known as symplesiomorphy). Following the br ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesothelae
The Mesothelae are a suborder of spiders (order Araneae) that includes a single extant family, Liphistiidae, and a number of extinct families. This suborder is thought to form the sister group to all other living spiders, and to retain ancestral characters, such as a segmented abdomen with spinnerets in the middle and two pairs of book lungs. Members of Liphistiidae are medium to large spiders with eight eyes grouped on a tubercle. They are found only in China, Japan, and southeast Asia. The oldest known Mesothelae spiders are known from the Carboniferous, over 300 million years ago. The Heptathelidae were once considered their own family; today they are considered a subfamily of the Liphistiidae. Description Members of Mesothelae have paraxial chelicerae, two pairs of coxal glands on the legs, eight eyes grouped on a nodule, two pairs of book lungs, and no endites on the base of the pedipalp. Most have at least seven or eight spinnerets near the middle of the abdomen. Later ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
