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33-606: CQV can refer to: Cat Que Virus, a type of virus spread by Culex mosquitoes in China Celui qui vit , meaning the person insured in life insurance COVID-19 Quarantine Victoria, an organization that handles the COVID-19 pandemic in Victoria , Australia CareGroup Center for Quality and Value, a data analysis firm that formerly hired John Halamka Topics referred to by

66-500: A yolk sac ), then to motile larvae (often known as fingerlings due to them roughly reaching the length of a human finger ) that have to forage for themselves after the yolk sac resorbs, and then to the juvenile stage where the fish progressively start to resemble adult morphology and behaviors until finally reaching sexual maturity . In typical amphibian development, eggs are laid in water and larvae are adapted to an aquatic lifestyle. Frogs , toads , and newts all hatch from

99-399: A butterfly 2 – The pupa is now spewing the thread to form chrysalis 3 – The chrysalis is fully formed 4 – Adult butterfly coming out of the chrysalis In cephalochordata , metamorphosis is iodothyronine -induced and it could be an ancestral feature of all chordates . Some fish, both bony fish (Osteichthyes) and jawless fish (Agnatha) , undergo metamorphosis. Fish metamorphosis

132-648: A complete metamorphosis, including a pupal or resting stage between the larval and adult forms. A number of hypotheses have been proposed to explain the evolution of holometaboly from hemimetaboly, mostly centering on whether or not the intermediate stages of hemimetabolous forms are homologous in origin to the pupal stage of holometabolous forms. According to a 2009 study, temperature plays an important role in insect development as individual species are found to have specific thermal windows that allow them to progress through their developmental stages. These windows are not significantly affected by ecological traits, rather,

165-413: A considerable role during physiological processes of multicellular organisms, particularly during embryogenesis , and metamorphosis. Additional research in 2019 found that both autophagy and apoptosis , the two ways programmed cell death occur, are processes undergone during insect metamorphosis. Below is the sequence of steps in the metamorphosis of the butterfly (illustrated): 1 – The larva of

198-411: A few species). The tiny, cigar-shaped, dark brown eggs adhere to each other through adhesion forces, not any kind of cement, and are easily separated. Eggs hatch only in the presence of water, and the larvae are obligately aquatic, linear in form, and maintain their position and mostly vertical attitude in water by movements of their bristly mouthparts. To swim, they lash their bodies back and forth through

231-466: A high level of juvenile hormone, the moult to the pupal stage has a low level of juvenile hormone, and the final, or imaginal , molt has no juvenile hormone present at all. Experiments on firebugs have shown how juvenile hormone can affect the number of nymph instar stages in hemimetabolous insects. In chordates, metamorphosis is iodothyronine-induced and an ancestral feature of all chordates . All three categories of metamorphosis can be found in

264-446: A hormone, the prothoracicotropic hormone (PTTH) that activates prothoracic glands, which secrete a second hormone, usually ecdysone (an ecdysteroid ), that induces ecdysis (shedding of the exoskeleton). PTTH also stimulates the corpora allata , a retrocerebral organ, to produce juvenile hormone , which prevents the development of adult characteristics during ecdysis . In holometabolous insects, molts between larval instars have

297-454: A long stage of growth followed by a more gradual metamorphosis to the migrating phase. In the pre-adult freshwater stage, the eel also has phenotypic plasticity because fish-eating eels develop very wide mandibles, making the head look blunt. Leptocephali are common, occurring in all Elopomorpha ( tarpon - and eel -like fish). Most other bony fish undergo metamorphosis initially from egg to immotile larvae known as sac fry ( fry with

330-461: A particular region. Nonanal has been identified as a compound that attracts Culex mosquitoes, perhaps pheromonally. Nonanal acts synergistically with carbon dioxide . Culex is a diverse genus. It comprises over 20 subgenera that include a total of well over 1,000 species. Publications of newly described species are frequent. Metamorphosis Generally organisms with a larval stage undergo metamorphosis, and during metamorphosis

363-420: A relatively long, spiral‐shaped gut to digest that diet. Recent studies suggest tadpoles do not have a balanced homeostatic feedback control system until the beginning stages of metamorphosis. At this point, their long gut shortens and begins favoring the diet of insects. Rapid changes in the body can then be observed as the lifestyle of the frog changes completely. The spiral‐shaped mouth with horny tooth ridges

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396-508: Is different from Wikidata All article disambiguation pages All disambiguation pages Culex Culex or typical mosquitoes are a genus of mosquitoes , several species of which serve as vectors of one or more important diseases of birds, humans, and other animals. The diseases they vector include arbovirus infections such as West Nile virus , Japanese encephalitis , or St. Louis encephalitis , but also filariasis and avian malaria . They occur worldwide except for

429-421: Is outside the parental body, development is subject to many adaptations due to specific ecological circumstances. For this reason tadpoles can have horny ridges for teeth, whiskers, and fins. They also make use of the lateral line organ. After metamorphosis, these organs become redundant and will be resorbed by controlled cell death, called apoptosis . The amount of adaptation to specific ecological circumstances

462-549: Is reabsorbed, due to the higher thyroxin concentrations required for tail resorption. Salamander development is highly diverse; some species go through a dramatic reorganization when transitioning from aquatic larvae to terrestrial adults, while others, such as the axolotl , display pedomorphosis and never develop into terrestrial adults. Within the genus Ambystoma , species have evolved to be pedomorphic several times, and pedomorphosis and complete development can both occur in some species. In newts, metamorphosis occurs due to

495-402: Is remarkable, with many discoveries still being made. With frogs and toads, the external gills of the newly hatched tadpole are covered with a gill sac after a few days, and lungs are quickly formed. Front legs are formed under the gill sac, and hindlegs are visible a few days later. Following that there is usually a longer stage during which the tadpole lives off a vegetarian diet. Tadpoles use

528-401: Is resorbed together with the spiral gut. The animal develops a big jaw, and its gills disappear along with its gill sac. Eyes and legs grow quickly, a tongue is formed, and all this is accompanied by associated changes in the neural networks (development of stereoscopic vision, loss of the lateral line system, etc.) All this can happen in about a day. It is not until a few days later that the tail

561-403: Is typically under strong control by the thyroid hormone. Examples among the non-bony fish include the lamprey . Among the bony fish, mechanisms are varied. The salmon is diadromous , meaning that it changes from a freshwater to a saltwater lifestyle. Many species of flatfish begin their life bilaterally symmetrical , with an eye on either side of the body; but one eye moves to join

594-411: The change in habitat, not a change in diet, because newt larvae already feed as predators and continue doing so as adults. Newts' gills are never covered by a gill sac and will be resorbed only just before the animal leaves the water. Adults can move faster on land than in water. Newts often have an aquatic phase in spring and summer, and a land phase in winter. For adaptation to a water phase, prolactin

627-428: The diversity of insects, including no metamorphosis ("ametaboly"), incomplete or partial metamorphosis ("hemimetaboly"), and complete metamorphosis ("holometaboly"). While ametabolous insects show very little difference between larval and adult forms (also known as " direct development "), both hemimetabolous and holometabolous insects have significant morphological and behavioral differences between larval and adult forms,

660-538: The eggs as larvae with external gills but it will take some time for the amphibians to interact outside with pulmonary respiration. Afterwards, newt larvae start a predatory lifestyle, while tadpoles mostly scrape food off surfaces with their horny tooth ridges. Metamorphosis in amphibians is regulated by thyroxin concentration in the blood, which stimulates metamorphosis, and prolactin , which counteracts its effect. Specific events are dependent on threshold values for different tissues. Because most embryonic development

693-655: The evolution of metamorphosis in insects is thought to have fuelled their dramatic radiation (1,2). Some early ametabolous "true insects" are still present today, such as bristletails and silverfish . Hemimetabolous insects include cockroaches , grasshoppers , dragonflies , and true bugs . Phylogenetically, all insects in the Pterygota undergo a marked change in form, texture and physical appearance from immature stage to adult. These insects either have hemimetabolous development, and undergo an incomplete or partial metamorphosis, or holometabolous development, which undergo

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726-416: The extreme northern parts of the temperate zone , and are the most common form of mosquito encountered in some major U.S. cities, such as Los Angeles . In naming this genus , Carl Linnaeus used the nonspecific Latin term for a midge or gnat: culex . Depending on the species, the adult Culex mosquito may measure from 4–10 mm (0.2–0.4 in). The adult morphology is typical of flies in

759-566: The most significant being the inclusion, in holometabolous organisms, of a pupal or resting stage between the larval and adult forms. In hemimetabolous insects , immature stages are called nymphs . Development proceeds in repeated stages of growth and ecdysis (moulting); these stages are called instars . The juvenile forms closely resemble adults, but are smaller and lack adult features such as wings and genitalia. The size and morphological differences between nymphs in different instars are small, often just differences in body proportions and

792-488: The number of segments; in later instars, external wing buds form. The period from one molt to the next is called a stadium. In holometabolous insects, immature stages are called larvae and differ markedly from adults. Insects which undergo holometabolism pass through a larval stage, then enter an inactive state called pupa (called a "chrysalis " in butterfly species), and finally emerge as adults. The earliest insect forms showed direct development ( ametabolism ), and

825-424: The organism loses larval characteristics. The word metamorphosis derives from Ancient Greek μεταμόρφωσις , "transformation, transforming", from μετα- ( meta- ), "after" and μορφή ( morphe ), "form". In insects, growth and metamorphosis are controlled by hormones synthesized by endocrine glands near the front of the body ( anterior ). Neurosecretory cells in an insect's brain secrete

858-469: The other side of the fish – which becomes the upper side – in the adult form. The European eel has a number of metamorphoses, from the larval stage to the leptocephalus stage, then a quick metamorphosis to glass eel at the edge of the continental shelf (eight days for the Japanese eel ), two months at the border of fresh and salt water where the glass eel undergoes a quick metamorphosis into elver, then

891-780: The presence or absence of various bristles or other bodily features. In the field, informal identification is more often important, and the first question as a rule is whether the mosquito is anopheline or culicine . Given a specimen in good condition, one of the first things to notice is the length of the maxillary palps. Especially in the female, palps as long as the proboscis are characteristic of anopheline mosquitoes. Culicine females have short palps. Anopheline mosquitoes tend to have dappled or spotted wings, while culicine wings tend to be clear. Anopheline mosquitoes tend to sit with their heads low and their rear ends raised high, especially when feeding, while culicine females keep their bodies horizontal. Anopheline larvae tend to float horizontal at

924-404: The pupa ruptures and the adult emerges from the shed exoskeleton. Diseases borne by one or more species of Culex mosquitoes vary in their dependence on the species of vector. Some are rarely and only incidentally transmitted by Culex species, but Culex and closely related genera of culicine mosquitoes readily support perennial epidemics of certain major diseases if they become established in

957-403: The same term [REDACTED] This disambiguation page lists articles associated with the title CQV . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=CQV&oldid=1167142594 " Category : Disambiguation pages Hidden categories: Short description

990-426: The suborder Nematocera with the head , thorax , and abdomen clearly defined and the two forewings held horizontally over the abdomen when at rest. As in all Diptera capable of flight, the second pair of wings is reduced and modified into tiny, inconspicuous halteres . Formal identification is important in mosquito control, but it is demanding and requires careful measurements of bodily proportions and noting

1023-563: The surface of the water when not in motion, whereas culicine larvae float with head low and only the siphon at the tail held at the surface. The developmental cycle of most species takes about two weeks in warm weather. The metamorphosis is typical of holometabolism in an insect: the female lays eggs in rafts of as many as 300 on the water's surface. Suitable habitats for egg-laying are small bodies of standing fresh water: puddles, pools, ditches, tin cans, buckets, bottles, unmounted tires, and water storage tanks (tree boles are suitable for only

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1056-461: The water. During the larval stage, the insect lives submerged in water and feeds on particles of organic matter, microscopic organisms or plant material; after several instars it then develops into a pupa . Unlike the larva, the pupa is comma-shaped. It does not feed, but can swim in rapid jerking motions to avoid potential predators. It must remain in regular contact with the surface to breathe, but it must not become desiccated. After 24–48 hours,

1089-529: The windows are phylogenetically adapted to the ecological circumstances insects are living in. According to research from 2008, adult Manduca sexta is able to retain behavior learned as a caterpillar . Another caterpillar, the ornate moth caterpillar , is able to carry toxins that it acquires from its diet through metamorphosis and into adulthood, where the toxins still serve for protection against predators. Many observations published in 2002, and supported in 2013 indicate that programmed cell death plays

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