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Tymbal
The tymbal (or timbal) is the corrugated exoskeletal structure used to produce sounds in insects. In male cicadas, the tymbals are membranes in the abdomen, responsible for the characteristic sound produced by the insect. In tiger moths, the tymbals are modified regions of the thorax, and produce high-frequency clicks. In lesser wax moths the left and right tymbals emit high frequency pulses that are used as mating calls. The paired tymbals of a cicada are located on the sides of the abdominal base. The "singing" of a cicada is not stridulation as in many other familiar sound-producing insects like crickets (where one structure is rubbed against another): the tymbals are regions of the exoskeleton that are modified to form a complex membrane with thin, membranous portions and thickened "ribs". These membranes vibrate rapidly, and enlarged chambers derived from the tracheae enable the cicada's body to be a resonance chamber, greatly amplifying the sound. Some cicadas produce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Resonance
Resonance describes the phenomenon of increased amplitude that occurs when the frequency of an applied Periodic function, periodic force (or a Fourier analysis, Fourier component of it) is equal or close to a natural frequency of the system on which it acts. When an Oscillation, oscillating force is applied at a resonant frequency of a dynamic system, the system will oscillate at a higher Amplitude, amplitude than when the same force is applied at other, non-resonant frequencies. Frequencies at which the response amplitude is a relative maximum are also known as resonant frequencies or resonance frequencies of the system. Small periodic forces that are near a resonant frequency of the system have the ability to produce large amplitude oscillations in the system due to the storage of vibrational energy. Resonance phenomena occur with all types of vibrations or waves: there is mechanical resonance, orbital resonance, acoustic resonance, Electromagnetic radiation, electromagnet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lower Hutt
Lower Hutt ( mi, Te Awa Kairangi ki Tai) is a city in the Wellington Region of New Zealand. Administered by the Hutt City Council, it is one of the four cities that constitute the Wellington metropolitan area. It is New Zealand's sixth most populous city, with a population of . The total area administered by the council is around the lower half of the Hutt Valley and along the eastern shores of Wellington Harbour, of which is urban. It is separated from the city of Wellington by the harbour, and from Upper Hutt by the Taita Gorge. Lower Hutt is unique among New Zealand cities, as the name of the council does not match the name of the city it governs. Special legislation has since 1991 given the council the name "Hutt City Council", while the name of the place itself remains "Lower Hutt City". This name has led to confusion, as Upper Hutt is administered by a separate city council, the Upper Hutt City Council. The entire Hutt Valley includes both Lower and Upper Hutt citie ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Echolocation Jamming In Animals
Echolocation (or sonar) systems of animals, like human radar systems, are susceptible to interference known as echolocation jamming or sonar jamming. Jamming occurs when non-target sounds interfere with target echoes. Jamming can be purposeful or inadvertent, and can be caused by the echolocation system itself, other echolocating animals, prey, or humans. Echolocating animals have evolved to minimize jamming, however; echolocation avoidance behaviors are not always successful. Self jamming Echolocating animals can jam themselves in a number of ways. Bats, for example, produce some of the loudest sounds in nature, and then they immediately listen for echoes that are hundreds of times fainter than the sounds they emit. To avoid deafening themselves, whenever a bat makes an echolocation emission, a small muscle in the bat's middle ear (the stapedius muscle) clamps down on small bones called ossicles, which normally amplify sounds between the ear drum and the cochlea. This dampens ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aposematism
Aposematism is the advertising by an animal to potential 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 coloration, sounds, odours, or other 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 possesses chemical or physical defences is not the only way t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Episternum
An interclavicle is a bone which, in most tetrapods, is located between the clavicles. Therian mammals ( marsupials and placentals) are the only tetrapods which never have an interclavicle, although some members of other groups also lack one. In therians, it is replaced by the sternum The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sha ... which is similar in shape and function but forms via endochondral ossification (cartilage forming bone). The interclavicle, on the other hand, develops through intramembranous ossification of the skin. Monotremes, although part of the mammalian class, do have interclavicles. References Bones of the upper limb Vertebrate anatomy {{Vertebrate anatomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metathorax
The metathorax is the posterior of the three segments in the thorax of an insect, and bears the third pair of legs. Its principal sclerites ( exoskeletal plates) are the metanotum (dorsal), the metasternum (ventral), and the metapleuron (lateral) on each side. The metathorax is the segment that bears the hindwings in most winged insects, though sometimes these may be reduced or modified, as in the flies ( Diptera), in which they are reduced to form halteres, or flightless, as in beetles ( Coleoptera), in which they may be completely absent even though forewings are still present. All adult insects possess legs on the metathorax. In most groups of insects, the metanotum is reduced relative to the mesonotum. In the suborder Apocrita of the Hymenoptera, the first abdominal segment is fused to the metathorax, and is then called the propodeum. See also * Glossary of entomology terms * Insect morphology *Mesothorax *Prothorax *Thorax (insect anatomy) The thorax is the midsection ( ta ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DB (SPL)
Sound pressure or acoustic pressure is the local pressure deviation from the ambient (average or equilibrium) atmospheric pressure, caused by a sound wave. In air, sound pressure can be measured using a microphone, and in water with a hydrophone. The SI unit of sound pressure is the pascal (Pa). Mathematical definition A sound wave in a transmission medium causes a deviation (sound pressure, a ''dynamic'' pressure) in the local ambient pressure, a ''static'' pressure. Sound pressure, denoted ''p'', is defined by p_\text = p_\text + p, where * ''p''total is the total pressure, * ''p''stat is the static pressure. Sound measurements Sound intensity In a sound wave, the complementary variable to sound pressure is the particle velocity. Together, they determine the sound intensity of the wave. ''Sound intensity'', denoted I and measured in W· m−2 in SI units, is defined by \mathbf I = p \mathbf v, where * ''p'' is the sound pressure, * v is the particle velocity. Acousti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Invertebrate Trachea
The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all air-breathing animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. The trachea is formed by a number of horseshoe-shaped rings, joined together vertically by overlying ligaments, and by the trachealis muscle at their ends. The epiglottis closes the opening to the larynx during swallowing. The trachea begins to form in the second month of embryo development, becoming longer and more fixed in its position over time. It is epithelium lined with column-shaped cells that have hair-like extensions called cilia, with scattered goblet cells that produce protective mucins. The trachea can be affected by inflammation or infection, usually as a result of a viral illness affecting other parts of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Exoskeleton
An exoskeleton (from Greek ''éxō'' "outer" and ''skeletós'' "skeleton") is an external skeleton that supports and protects an animal's body, in contrast to an internal skeleton (endoskeleton) in for example, a human. In usage, some of the larger kinds of exoskeletons are known as " shells". Examples of exoskeletons within animals include the arthropod exoskeleton shared by chelicerates, myriapods, crustaceans, and insects, as well as the shell of certain sponges and the mollusc shell shared by snails, clams, tusk shells, chitons and nautilus. Some animals, such as the turtle, have both an endoskeleton and an exoskeleton. Role Exoskeletons contain rigid and resistant components that fulfill a set of functional roles in many animals including protection, excretion, sensing, support, feeding and acting as a barrier against desiccation in terrestrial organisms. Exoskeletons have a role in defense from pests and predators, support and in providing an attachment framewo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cricket (insect)
Crickets are orthopteran insects which are related to bush crickets, and, more distantly, to grasshoppers. In older literature, such as Imms,Imms AD, rev. Richards OW & Davies RG (1970) ''A General Textbook of Entomology'' 9th Ed. Methuen 886 pp. "crickets" were placed at the family level (''i.e.'' Gryllidae), but contemporary authorities including Otte now place them in the superfamily Grylloidea. The word has been used in combination to describe more distantly related taxa in the suborder Ensifera, such as king crickets and mole crickets. Crickets have mainly cylindrically-shaped bodies, round heads, and long antennae. Behind the head is a smooth, robust pronotum. The abdomen ends in a pair of long cerci; females have a long, cylindrical ovipositor. Diagnostic features include legs with 3-segmented tarsi; as with many Orthoptera, the hind legs have enlarged femora, providing power for jumping. The front wings are adapted as tough, leathery elytra, and some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stridulation
Stridulation is the act of producing sound by rubbing together certain body parts. This behavior is mostly associated with insects, but other animals are known to do this as well, such as a number of species of fish, snakes and spiders. The mechanism is typically that of one structure with a well-defined lip, ridge, or nodules (the "scraper" or ''plectrum'') being moved across a finely-ridged surface (the "file" or ''stridulitrum''—sometimes called the ''pars stridens'') or vice versa, and vibrating as it does so, like the dragging of a phonograph needle across a vinyl record. Sometimes it is the structure bearing the file which resonates to produce the sound, but in other cases it is the structure bearing the scraper, with both variants possible in related groups. Common onomatopoeic words for the sounds produced by stridulation include ''chirp'' and ''chirrup''. Arthropod stridulation Insects and other arthropods stridulate by rubbing together two parts of the body. These ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
