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Redfin Pickerel
The redfin pickerel (''Esox americanus americanus'') is a subspecies of freshwater fish belonging to the pike family (Esocidae) of the order Esociformes. Not to be confused with its close relatives, the grass pickerel and the chain pickerel, this fish is unique in the fact that it has brightly colored red fins. Like all pikes, the redfin pickerel is an ambush predator, lying amongst thick vegetation in wait for smaller, more agile prey to enter within its range of attack. Distribution and habitat The redfin pickerel can be found in freshwater lakes, streams, and swamps along the Atlantic slope. Stable populations extend from Massachusetts to Florida's Okeechobee Lake, and west into Gulf drainages up to Mississippi's Pascagoula River. Because the redfin pickerel is an ambush predator, the fish prefers freshwater habitats with high visibility and dense vegetation or decaying organic matter in which to hide itself. Physiology The redfin pickerel, like other fish of the Esox gen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Johann Friedrich Gmelin
Johann Friedrich Gmelin (8 August 1748 – 1 November 1804) was a German natural history, naturalist, botanist, entomologist, herpetologist, and malacologist. Education Johann Friedrich Gmelin was born as the eldest son of Philipp Friedrich Gmelin in 1748 in Tübingen. He studied medicine under his father at University of Tübingen and graduated with a Master's degree in 1768, with a thesis entitled: ', defended under the presidency of Ferdinand Christoph Oetinger, whom he thanks with the words '. Career In 1769, Gmelin became an adjunct professor of medicine at University of Tübingen. In 1773, he became professor of philosophy and adjunct professor of medicine at University of Göttingen. He was promoted to full professor of medicine and professor of chemistry, botany, and mineralogy in 1778. He died in 1804 in Göttingen. Johann Friedrich Gmelin when young became an "apostle" of Carl Linnaeus, probably when Linnaeus was working in the Netherlands, and undertook a plant-c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Predation
Predation is a biological interaction In ecology, a biological interaction is the effect that a pair of organisms living together in a community have on each other. They can be either of the same species (intraspecific interactions), or of different species ( interspecific interactio ... where one organism, the predator, kills and eats another organism, its prey. It is one of a family of common feeding behaviours that includes parasitism and micropredation (which usually do not kill the host) and parasitoidism (which always does, eventually). It is distinct from scavenging on dead prey, though many predators also scavenge; it overlaps with herbivory, as seed predators and destructive frugivores are predators. Predators may actively search for or pursue prey or wait for it, often concealed. When prey is detected, the predator assesses whether to attack it. This may involve ambush predation, ambush or pursuit predation, sometimes after stalking the prey. If the attack ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Camouflage
Camouflage is the use of any combination of materials, coloration, or illumination for concealment, either by making animals or objects hard to see, or by disguising them as something else. Examples include the leopard's spotted coat, the battledress of a modern soldier, and the leaf-mimic katydid's wings. A third approach, motion dazzle, confuses the observer with a conspicuous pattern, making the object visible but momentarily harder to locate, as well as making general aiming easier. The majority of camouflage methods aim for crypsis, often through a general resemblance to the background, high contrast disruptive coloration, eliminating shadow, and countershading. In the open ocean, where there is no background, the principal methods of camouflage are transparency, silvering, and countershading, while the bioluminescence, ability to produce light is among other things used for counter-illumination on the undersides of cephalopods such as squid. Some animals, such as chamel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventral
Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position provides a definition of what is at the front ("anterior"), behind ("posterior") and so on. As part of defining and describing terms, the body is described through the use of anatomical planes and anatomical axes. The meaning of terms that are used can change depending on whether an organism is bipedal or quadrupedal. Additionally, for some animals such as invertebrates, some terms may not have any meaning at all; for example, an animal that is radially symmetrical will have no anterior surface, but can still have a description that a part is close to the middle ("proximal") or further from the middle ("distal"). International organisations have determined vocabularies that are often used as standard vocabularies for subdisciplines of anatomy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrodynamic
In physics and engineering, fluid dynamics is a subdiscipline of fluid mechanics that describes the flow of fluids—liquids and gases. It has several subdisciplines, including ''aerodynamics'' (the study of air and other gases in motion) and hydrodynamics (the study of liquids in motion). Fluid dynamics has a wide range of applications, including calculating forces and moments on aircraft, determining the mass flow rate of petroleum through pipelines, predicting weather patterns, understanding nebulae in interstellar space and modelling fission weapon detonation. Fluid dynamics offers a systematic structure—which underlies these practical disciplines—that embraces empirical and semi-empirical laws derived from flow measurement and used to solve practical problems. The solution to a fluid dynamics problem typically involves the calculation of various properties of the fluid, such as flow velocity, pressure, density, and temperature, as functions of space and time. Be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adaptations
In biology, adaptation has three related meanings. Firstly, it is the dynamic evolutionary process of natural selection that fits organisms to their environment, enhancing their evolutionary fitness. Secondly, it is a state reached by the population during that process. Thirdly, it is a phenotypic trait or adaptive trait, with a functional role in each individual organism, that is maintained and has evolved through natural selection. Historically, adaptation has been described from the time of the ancient Greek philosophers such as Empedocles and Aristotle. In 18th and 19th century natural theology, adaptation was taken as evidence for the existence of a deity. Charles Darwin proposed instead that it was explained by natural selection. Adaptation is related to biological fitness, which governs the rate of evolution as measured by change in allele frequencies. Often, two or more species co-adapt and co-evolve as they develop adaptations that interlock with those of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thrust
Thrust is a reaction force In physics, a force is an influence that can change the motion of an object. A force can cause an object with mass to change its velocity (e.g. moving from a state of rest), i.e., to accelerate. Force can also be described intuitively as a p ... described quantitatively by Newton's third law. When a system expels or accelerates mass in one direction, the accelerated mass will cause a force of equal magnitude but opposite direction to be applied to that system. The force applied on a surface in a direction perpendicular or normal vector, normal to the surface is also called thrust. Force, and thus thrust, is measured using the International System of Units (SI) in newton (unit), newtons (symbol: N), and represents the amount needed to accelerate 1 kilogram of mass at the rate of 1 Metre per second squared, meter per second per second. In mechanical engineering, force orthogonal to the main load (such as in parallel helical gears) is referre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caudal Fin
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pectoral Fins
Fins are distinctive anatomical features composed of bony spines or rays protruding from the body of a fish. They are covered with skin and joined together either in a webbed fashion, as seen in most bony fish, or similar to a flipper, as seen in sharks. Apart from the tail or caudal fin, fish fins have no direct connection with the spine and are supported only by muscles. Their principal function is to help the fish swim. Fins located in different places on the fish serve different purposes such as moving forward, turning, keeping an upright position or stopping. Most fish use fins when swimming, flying fish use pectoral fins for gliding, and frogfish use them for crawling. Fins can also be used for other purposes; male sharks and mosquitofish use a modified fin to deliver sperm, thresher sharks use their caudal fin to stun prey, reef stonefish have spines in their dorsal fins that inject venom, anglerfish use the first spine of their dorsal fin like a fishing rod to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ventral Fin
Pelvic fins or ventral fins are paired fins located on the ventral surface of fish. The paired pelvic fins are homologous Homology may refer to: Sciences Biology *Homology (biology), any characteristic of biological organisms that is derived from a common ancestor *Sequence homology, biological homology between DNA, RNA, or protein sequences * Homologous chrom ... to the hindlimbs of tetrapods. Structure and function Structure In actinopterygians, the pelvic fin consists of two endochondrally-derived bony girdles attached to bony radials. Dermal fin rays ( lepidotrichia) are positioned distally from the radials. There are three pairs of muscles each on the dorsal and ventral side of the pelvic fin girdle that abduct and adduct the fin from the body. Pelvic fin structures can be extremely specialized in actinopterygians. Gobiids and lumpsuckers modify their pelvic fins into a sucker disk that allow them to adhere to the substrate or climb structures, such as wat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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