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Counter Shading
Countershading, or Thayer's law, is a method of camouflage in which an animal's coloration is darker on the top or upper side and lighter on the underside of the body. This pattern is found in many species of mammals, reptiles, birds, fish, and insects, both in predators and in prey. When light falls from above on a uniformly coloured three-dimensional object such as a sphere, it makes the upper side appear lighter and the underside darker, grading from one to the other. This pattern of light and shade makes the object appear solid, and therefore easier to detect. The classical form of countershading, discovered in 1909 by the artist Abbott Handerson Thayer, works by counterbalancing the effects of self-shadowing, again typically with grading from dark to light. In theory this could be useful for military camouflage, but in practice it has rarely been applied, despite the best efforts of Thayer and, later, in the Second World War, of the zoologist Hugh Cott. The precise func ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tiburón
Tiburon (Spanish ''Tiburón'', "shark") may refer to: Places ;United States * Tiburon, California * Tiburón Golf Club Naples, Florida * Tiburon Peninsula (California), a peninsula in the San Francisco Bay Area of California ;Mexico * Tiburón Island, an island in the Gulf of California ;Haiti * Tiburon Peninsula, Haiti * Tiburon, Sud, commune in Haiti ;Denmark * Thyborøn, a fishing village on the west coast of Jutland Arts * ''Tiburon'', a 1935 prize winning first novel about the people of the eponymous town by Kylie Tennant * ''El Tiburón'', a single by Proyecto Uno. Also covered by Henry Mendez *Tiburón (Rubén Blades song), "Tiburón" (Rubén Blades song), by Willie Colón and Rubén Blades Others * Hyundai Tiburon, a car built by the Hyundai Motor Company * Hoyt Tiburon, a take-down recurve bow built by Hoyt Archery * USS Tiburon (SS-529), USS ''Tiburon'' (SS-529) * ROV ''Tiburon'', a deep-sea research robot of the R/V Western Flyer, R/V ''Western Flyer'' * EA Tiburon, an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Counter-illumination
Counter-illumination is a method of active camouflage seen in marine animals such as firefly squid and midshipman fish, and in military prototypes, producing light to match their backgrounds in both brightness and wavelength. Marine animals of the mesopelagic (mid-water) zone tend to appear dark against the bright water surface when seen from below. They can camouflage themselves, often from predators but also from their prey, by producing light with bioluminescent photophores on their downward-facing surfaces, reducing the contrast of their silhouettes against the background. The light may be produced by the animals themselves, or by symbiotic bacteria, often '' Aliivibrio fischeri''. Counter-illumination differs from countershading, which uses only pigments such as melanin to reduce the appearance of shadows. It is one of the dominant types of aquatic camouflage, along with transparency and silvering. All three methods make animals in open water resemble their envir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zoologist
Zoology ()The pronunciation of zoology as is usually regarded as nonstandard, though it is not uncommon. is the branch of biology that studies the animal kingdom, including the structure, embryology, evolution, classification, habits, and distribution of all animals, both living and extinct, and how they interact with their ecosystems. The term is derived from Ancient Greek , ('animal'), and , ('knowledge', 'study'). Although humans have always been interested in the natural history of the animals they saw around them, and made use of this knowledge to domesticate certain species, the formal study of zoology can be said to have originated with Aristotle. He viewed animals as living organisms, studied their structure and development, and considered their adaptations to their surroundings and the function of their parts. The Greek physician Galen studied human anatomy and was one of the greatest surgeons of the ancient world, but after the fall of the Western Roman Empire ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
England
England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe by the North Sea to the east and the English Channel to the south. The country covers five-eighths of the island of Great Britain, which lies in the North Atlantic, and includes over 100 smaller islands, such as the Isles of Scilly and the Isle of Wight. The area now called England was first inhabited by modern humans during the Upper Paleolithic period, but takes its name from the Angles, a Germanic tribe deriving its name from the Anglia peninsula, who settled during the 5th and 6th centuries. England became a unified state in the 10th century and has had a significant cultural and legal impact on the wider world since the Age of Discovery, which began during the 15th century. The English language, the Anglican Church, and Eng ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luna Moth
The Luna moth (''Actias luna'') also known as the American moon moth is a Nearctic moth in the family Saturniidae, subfamily Saturniinae, a group commonly known as giant silk moths. It has lime-green colored wings and a white body. The larvae (caterpillars) are also green. Typically, it has a wingspan of roughly , but can exceed , making it one of the larger moths in North America. Across Canada, it has one generation per year, with the winged adults appearing in late May or early June, whereas farther south it will have two or even three generations per year, the first appearance as early as March in southern parts of the United States. As defense mechanisms, larvae emit clicks as a warning and can also regurgitate intestinal contents, confirmed as having a deterrent effect on a variety of predators. The elongated tails of the hindwings are thought to confuse the echolocation detection used by predatory bats. A parasitoid fly deliberately introduced to North America to be a b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nile Catfish
right ''Synodontis batensoda'', the upside-down catfish, is a species of mochokid upside-down catfish. It is unevenly distributed in inland waters across Africa from Senegal to Ethiopia, and is also known as a squeaker or giant upside-down catfish. It was originally described by Eduard Rüppell in 1832 in the paper "Continuation of the description and figure of several new fish, in the Nile. p1-14". The species is now regionally extinct in Northern Africa, but used to be found in Cairo during floods. It can be found in portions of the White Nile, Blue Nile, and the Baro Rivers in northeast Africa, and the Chad, Niger, Senegal, and Gambia river basins in western Africa. It occurs in slow-moving waters and marshes bordering large rivers. Water temperatures in its native habitat range from . ''Synodontis batensoda'' is silver-green to blue-grey with black barbels and a blackish underside (thus its specific name, from Arabic بطن السوداء ''bațn sawdā''' = "black b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aposematism
Aposematism is the Advertising in biology, advertising by an animal to potential predation, predators that it is not worth attacking or eating. This unprofitability may consist of any defences which make the prey difficult to kill and eat, such as toxicity, venom, foul taste or smell, sharp spines, or aggressive nature. These advertising signals may take the form of conspicuous animal coloration, coloration, sounds, odours, or other perception, perceivable characteristics. Aposematic signals are beneficial for both predator and prey, since both avoid potential harm. The term was coined in 1877 by Edward Bagnall Poulton for Alfred Russel Wallace's concept of warning coloration. Aposematism is exploited in Müllerian mimicry, where species with strong defences evolve to resemble one another. By mimicking similarly coloured species, the warning signal to predators is shared, causing them to learn more quickly at less of a cost. A genuine aposematic signal that a species actually ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Signalling Theory
Within evolutionary biology, signalling theory is a body of theoretical work examining communication between individuals, both within species and across species. The central question is when organisms with conflicting interests, such as in sexual selection, should be expected to provide honest signals (no presumption being made of conscious intention) rather than cheating. Mathematical models describe how signalling can contribute to an evolutionarily stable strategy. Signals are given in contexts such as mate selection by females, which subjects the advertising males' signals to selective pressure. Signals thus evolve because they modify the behaviour of the receiver to benefit the signaller. Signals may be honest, conveying information which usefully increases the fitness of the receiver, or dishonest. An individual can cheat by giving a dishonest signal, which might briefly benefit that signaller, at the risk of undermining the signalling system for the whole population. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deimatic Behaviour
Deimatic behaviour or startle display means any pattern of bluffing behaviour in an animal that lacks strong defences, such as suddenly displaying conspicuous eyespots, to scare off or momentarily distract a predator, thus giving the prey animal an opportunity to escape. The term deimatic or dymantic originates from the Greek δειματόω (deimatóo), meaning "to frighten". Deimatic display occurs in widely separated groups of animals, including moths, butterflies, mantises and phasmids among the insects. In the cephalopods, different species of octopuses, squids, cuttlefish and the paper nautilus are deimatic. Displays are classified as deimatic or aposematic by the responses of the animals that see them. Where predators are initially startled but learn to eat the displaying prey, the display is classed as deimatic, and the prey is bluffing; where they continue to avoid the prey after tasting it, the display is taken as aposematic, meaning the prey is genuinely distastef ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skunk
Skunks are mammals in the family Mephitidae. They are known for their ability to spray a liquid with a strong, unpleasant scent from their anal glands. Different species of skunk vary in appearance from black-and-white to brown, cream or ginger colored, but all have warning coloration. While related to polecats and other members of the weasel family, skunks have as their closest relatives the Old World stink badgers. Taxonomy In alphabetical order, the living species of skunks are: * Family Mephitidae ** Genus: '' Conepatus'' *** ''Conepatus chinga'' – Molina's hog-nosed skunk *** ''Conepatus humboldtii'' – Humboldt's hog-nosed skunk *** ''Conepatus leuconotus'' – American hog-nosed skunk *** ''Conepatus semistriatus'' – striped hog-nosed skunk ** Genus: '' Mephitis'' *** ''Mephitis macroura'' – hooded skunk *** ''Mephitis mephitis'' – striped skunk ** Genus: '' Spilogale'' *** ''Spilogale angustifrons'' – souther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prototype
A prototype is an early sample, model, or release of a product built to test a concept or process. It is a term used in a variety of contexts, including semantics, design, electronics, and software programming. A prototype is generally used to evaluate a new design to enhance precision by system analysts and users. Prototyping serves to provide specifications for a real, working system rather than a theoretical one. In some design workflow models, creating a prototype (a process sometimes called materialization) is the step between the formalization and the evaluation of an idea. A prototype can also mean a typical example of something such as in the use of the derivation 'prototypical'. This is a useful term in identifying objects, behaviours and concepts which are considered the accepted norm and is analogous with terms such as stereotypes and archetypes. The word ''prototype'' derives from the Greek , "primitive form", neutral of , "original, primitive", from πρ� ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
