A poikilotherm ( / ˈ p ɔɪ k ə l ə ˌ θ ɜːr m , p ɔɪ ˈ k ɪ l ə ˌ θ ɜːr m / ) is an animal (Greek poikilos – 'various, spotted', and therme – 'heat) whose internal temperature varies considerably. Poikilotherms have to survive and adapt to environmental stress. One of the most important stressors is temperature change, which can lead to alterations in membrane lipid order and can cause protein unfolding and denaturation at elevated temperatures. It is the opposite of a homeotherm , an animal which maintains thermal homeostasis . While the term in principle can apply to all organisms , it is generally only applied to animals, and mostly to vertebrates . Usually the fluctuations are a consequence of variation in the ambient environmental temperature . Many terrestrial ectotherms are poikilothermic. However some ectotherms remain in temperature-constant environments to the point that they are actually able to maintain a constant internal temperature and are considered homeothermic . It is this distinction that often makes the term "poikilotherm" more useful than the vernacular "cold-blooded", which is sometimes used to refer to ectotherms more generally.
34-574: Calliphora is a genus of blow flies , also known as bottle flies, found in most parts of the world, with the highest diversity in Australia. The most widespread species in North America area Calliphora livida , C. vicina , and C. vomitoria . Calliphora , meaning "bearer of beauty", was first formally named in 1830 by Jean-Baptiste Robineau-Desvoidy . It is the type genus of the family Calliphoridae . Adults of Calliphora have
68-418: A given food source can support a greater density of poikilothermic animals than homeothermic animals. This is reflected in the predator-prey ratio which is usually higher in poikilothermic fauna compared to homeothermic ones. However, when homeotherms and poikilotherms have similar niches, and compete, the homeotherm can often drive poikilothermic competitors to extinction, because homeotherms can gather food for
102-432: A greater fraction of each day and in more effective, specialized ways (e.g. chimpanzees actively seeking out and collecting army ants with sticks versus the typical poikilotherm sit-and-wait strategy). In medicine, loss of normal thermoregulation is referred to as poikilothermia . This can be seen in compartment syndrome and with use of sedative-hypnotics like barbiturates , ethanol , and chloral hydrate . REM sleep
136-471: A grey or black thorax, the colour dulled by a heavy microtomentum. The abdomen is metallic blue (rarely purple or green) and sometimes also dulled by microtomentum. The suprasquamal ridge is bare or with inconspicuous fine setae only. The first flagellomere of the antenna is more than twice the length of the pedicel. Larvae have two posterior spiracles with a thick and unbroken peritreme, and (like other Calliphoridae larvae) containing straight slits. There
170-484: A root meaning "dappled" or "painted," and thermos ( θερμός ), meaning "heat". Poikilotherm animals must be able to function over a wider range of temperatures than homeotherms. The speed of most chemical reactions vary with temperature, and in order to function poikilotherms may have four to ten enzyme systems that operate at different temperatures for an important chemical reaction. As a result, poikilotherms often have larger, more complex genomes than homeotherms in
204-513: A source of carbohydrates to fuel flight, but just how and when this happens is unknown. One study showed the visual stimulus a blowfly receives from its compound eyes is responsible for causing its legs to extend from its flight position and allow it to land on any surface. Larvae of most species are scavengers of carrion and dung, and most likely constitute the majority of the maggots found in such material, although they are not uncommonly found in close association with other dipterous larvae from
238-519: A sterile screwworm fly production plant and release program in the eastern half of the Republic of Panama to keep fertile screwworms from migrating north. Currently, this species is limited to lowland tropical countries in South America and some Caribbean islands. The Old World primary screwworm ( Chrysomya bezziana ) is an obligate parasite of mammals. This fly is distributed throughout
272-418: A year in losses. The most common causes of myiasis in humans and animals are the three dipteran families Oestridae , Calliphoridae, and Sarcophagidae . Myiasis in humans is clinically categorized in six ways: dermal and subdermal, facial cavity, wound or trauma, gastrointestinal, vaginal, and generalized. If found in humans, the dipteran larvae are usually in their first instar. The only treatment necessary
306-521: Is a selected list of genera from the Palearctic , Nearctic , Malaysia (Japan) and Australasia : Blowflies have caught the interest of researchers in a variety of fields, although the large body of literature on calliphorids has been concentrated on solving the problem of myiasis in livestock. The sheep blowfly Lucilia cuprina causes the Australian sheep industry an estimated AU$ 170 million
340-450: Is an accessory sclerite between the mouth hooks, though this is not visible in whole larvae. Species in the genus Calliphora include: Blow flies The Calliphoridae (commonly known as blow flies , blow-flies , carrion flies , bluebottles , or greenbottles ) are a family of insects in the order Diptera , with almost 1,900 known species. The maggot larvae, often used as fishing bait, are known as gentles . The family
374-629: Is found throughout the United States and the American tropics, and in southern Canada during summers. This species is one of the most common species found on decomposing remains in the US South. Maggot debridement therapy (MDT) is the medical use of selected, laboratory-raised fly larvae for cleaning nonhealing wounds. Medicinal maggots perform debridement by selectively eating only dead tissue. Lucilia sericata ( Phaenicia sericata ), or
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#1732776845423408-625: Is just to remove the maggots, and the patient heals naturally. Whilst not strictly a myiasis species, the Congo floor maggot feeds on mammal blood, occasionally human. The New World primary screwworm ( Cochliomyia hominivorax ), once a major pest in Southern United States , has been eradicated from the United States, Mexico, and Central America through an extensive release program by the USDA of sterilized males . The USDA maintains
442-423: Is known to be polyphyletic , but much remains disputed regarding proper treatment of the constituent taxa, some of which are occasionally accorded family status (e.g., Bengaliidae and Helicoboscidae). Calliphoridae adults are commonly shiny with metallic colouring, often with blue, green, or black thoraces and abdomens. Antennae are three-segmented and aristate. The aristae are plumose their entire length, and
476-455: Is low. For the same body weight, poikilotherms need only 5 to 10% of the energy of homeotherms . It is comparatively easy for a poikilotherm to accumulate enough energy to reproduce. Poikilotherms at the same trophic level often have much shorter generations than homeotherms: weeks rather than years. Such applies even to animals with similar ecological roles such as cats and snakes . This difference in energy requirement also means that
510-585: Is not limited to blow flies, these maggots are a major source of this skin invasion, causing lesions, which, if severe enough, may be lethal. Strike starts when blow flies lay eggs in a wound or fecal material present on the sheep. When the maggots hatch, they begin feeding on the sheep and thus irritating it. As soon as the first wave of maggots hatch, they attract more blow flies, causing the strike. Insecticides are available for blow fly prevention (typically containing cypermethrin ), and precautionary measures may be taken, such as docking tails , shearing, and keeping
544-402: Is that females visit carrion both for protein and egg laying, but this remains to be proven. Blow fly eggs, usually yellowish or white in color, are about 1.5 mm × 0.4 mm, and when laid, look like rice grains. While the female blow fly typically lays 150–200 eggs per batch, she is usually iteroparous , laying around 2,000 eggs during the course of her life. The sex ratio of blow fly eggs
578-450: Is usually 50:50, but one exception is females from two species of the genus Chrysomya ( C. rufifacies and C. albiceps ), which are either arrhenogenic (laying only male offspring) or thelygenic (laying only female offspring). Hatching from an egg to the first larval stage takes about 8 hours to a day. Larvae have three stages of development ( instars ); each stage is separated by a molting event. The instars are separable by examining
612-701: The Old World, including Southeast Asia, tropical and subtropical Africa, some countries in the Middle East, India, the Malay Peninsula , the Indonesian and Philippine Islands , and Papua New Guinea. The secondary screwworm ( Cochliomyia macellaria ) has become one of the principal species on which to base post mortem interval estimations because its succession and occurrence on decomposing remains has been well defined. The secondary screwworm
646-526: The abdominal dorsum of the flies and eventually kills them About 1,900 species of blow flies are known, with 120 species in the Neotropics , and a large number of species in Africa and Southern Europe. The typical habitats for blow flies are temperate to tropical areas that provide a layer of loose, damp soil and litter where larvae may thrive and pupate. Sources: MYIA, FE, Nomina, A/O DC This
680-505: The ability to smell dead animal matter from up to 1 mi (1.6 km) away. Upon reaching the carrion, females deposit eggs on it. Since development is highly predictable if the ambient temperature is known, blow flies are considered a valuable tool in forensic science . Blow flies are used forensically to estimate the minimum post mortem interval (PMI min ) for human corpses. Traditional estimations of time since death are generally unreliable after 72 hours and often entomologists are
714-714: The adults can be necrophagous or vegetative. During the process of decay, microorganisms (e.g. Mycobacterium ) may be released through the body. Flies arrive at the scene and lay their eggs. The larvae begin eating and breaking down the corpse, simultaneously ingesting these organisms which is the first step of one transmission route. The bacterium which causes paratuberculosis in cattle, pigs and birds ( M. a. avium ) has been isolated and recovered from these flies through several different experiments. Other potential and threatening diseases include rabbit haemorrhagic disease in New Zealand and flystrike . Although strike
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#1732776845423748-523: The black blow fly Phormia regina can change from egg to pupa in 150–266 hours (six to 11 days). When the third larval stage is complete, it leaves the corpse and burrows into the ground to pupate, emerging as an adult 7–14 days later. Adult blowflies are occasional pollinators , being attracted to flowers with strong odors resembling rotting meat, such as the American pawpaw or dead horse arum . Little doubt remains that these flies use nectar as
782-583: The common green bottlefly, is the preferred species used in maggot therapy. MDT can be used to treat pressure ulcers, diabetic foot wounds, venous stasis ulcers, and postsurgical wounds. Adults may be vectors of pathogens of diseases such as dysentery . Flies, most commonly Calliphoridae, have frequently been associated with disease transmission in humans and animals, as well as myiasis. Studies and research have linked Calliphora and Lucilia to vectors of causal agents of bacterial infections. These larvae, commonly seen on decaying bodies, feed on carrion while
816-499: The continuous dorsal suture across the middle, along with well-defined posterior calli. The postscutellum is absent or weakly developed. The costa is unbroken and the subcosta is apparent on the insect. Most species of blow flies studied thus far are anautogenous ; a female requires a substantial amount of protein to develop mature eggs within her ovaries (about 800 μg per pair of ovaries in Phormia regina ). The current theory
850-499: The families Sarcophagidae and Muscidae , and many other acalyptrate muscoid flies. Predators of blow flies include spiders, beetles, frogs, and birds, including chickens. In the Chihuahuan desert of Mexico, a fungus, Furia vomitoriae (Rozsypal) Humber (1989) (from the family of Entomophthoraceae ) affects bluebottle flies. It forms masses of conidiophores erupting through the intersegmental areas (or clear bands) on
884-439: The genus Lucilia can sense death and show up right before it even occurs. Poikilothermic Poikilothermic animals include types of vertebrate animals, specifically some fish, amphibians, and reptiles, as well as many invertebrate animals. The naked mole-rat and sloth are some of the rare mammals which are poikilothermic. The term derives from Greek poikilos ( ποικίλος ), meaning "varied," ultimately from
918-452: The main crop pollinating insect. They visit (and thus may pollinate) flowers of a wide range of plants, including crop plants (e.g. avocado , mango , onion , leek , carrot , cauliflower ). Their sponging mouthparts mean that when visiting flowers, their head and upper body must broadly contact the inside of the flower. They have numerous hairs, including on the head and thorax, which may help them carry pollen , and indeed calliphorids in
952-898: The only officials capable of generating an accurate approximate time interval. The specialized discipline related to this practice is known as forensic entomology . In addition to being used to estimate the PMI min , assuming colonization occurred after death, blow fly specimens found infesting a human corpse are used to determine if the corpse was relocated or if the individual ingested narcotics prior to death. Calliphora vicina and Cynomya mortuorum are important flies of forensic entomology. Other forensically important Calliphoridae are Phormia regina , Calliphora vomitoria , Calliphora livida , Lucilia cuprina , Lucilia sericata , Lucilia illustris , Chrysomya rufifacies , Chrysomya megacephala , Cochliomyia macellaria , and Protophormia terraenovae . One myth states that species from
986-406: The posterior spiracles, or openings to the breathing system. The larvae use proteolytic enzymes in their excreta (as well as mechanical grinding by mouth hooks) to break down proteins on the livestock or corpse on which they are feeding. Blow flies are poikilothermic – the rate at which they grow and develop is highly dependent on temperature and species. Under room temperature (about 20 °C),
1020-639: The same ecological niche . Frogs are a notable example of this effect, though their complex development is also an important factor in their large genome. Because their metabolism is variable and generally below that of homeothermic animals , sustained high-energy activities like powered flight in large animals or maintaining a large brain is generally beyond poikilotherm animals. The metabolism of poikilotherms favors strategies such as sit-and-wait hunting over chasing prey for larger animals with high movement cost. As they do not use their metabolisms to heat or cool themselves, total energy requirement over time
1054-524: The second antennal segment is distinctly grooved. Members of Calliphoridae have branched Rs 2 veins, frontal sutures are present, and calypters are well developed. The characteristics and arrangements of hairlike bristles are used to differentiate among members of this family. All blowflies have bristles located on the meron . Having two notopleural bristles and a hindmost posthumeral bristle located lateral to presutural bristle are characteristics to look for when identifying this family. The thorax has
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1088-399: The sheep healthy overall. Salmonellosis has also been proven to be transmitted by the blow fly through saliva, feces and direct contact by the flies' tarsi. Adult flies may be able to spread pathogens via their sponging mouthparts, vomit, intestinal tract, sticky pads of their feet, or even their body or leg hairs. As the flies are vectors of many diseases, the importance of identifying
1122-417: The transmissible agents, the route of transmission, and prevention and treatments in the event of contact are becoming increasingly important. With the ability to lay hundreds of eggs in a lifetime and the presence of thousands of larvae at a time in such close proximity, the potential for transmission is high, especially at ideal temperatures. Calliphoridae are, alongside managed and wild bees , likely to be
1156-467: The wild have been observed carrying large amounts of pollen. Compared to honey bees , blow flies are active under a broader range of environmental conditions. However, it is unknown how their pollination abilities compare to those of bees, there are few studies assessing their contribution to pollination, and the exact species that pollinate are often not identified. Blow flies are usually the first insects to come in contact with carrion because they have
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