Necrophage

s facilitate the energy-efficient gliding vultures need to cover long distances in search of carrion, but reduce the agility needed to kill prey. Animals that eat carrion opportunistically and retain the traits needed to find and consume other food sources are described as 'facultative necrophages' and 'generalists'. These terms differentiate animals feeding on moist, putrefying tissue from animals feeding on desiccated and keratinized tissues. == Invertebrates ==

Flies '', a species of blow fly, laying eggs in a dead baby bird. The European bone skipper, Thyreophora cynophila, is an obligately necrophagous fly. It relies on carrion bone marrow in the first stage of its life cycle. Many other types of fly are facultatively necrophagous. Examples commonly found on land include blow flies, flesh flies, muscid flies, black soldier flies, ensign flies and thread-horns. Other necrophagous flies, for example black flies and lake flies, are semi-aquatic. Types of carrion fed upon include wildlife, livestock and poultry carcasses, slaughterhouse and fishing discards, and human bodies. and are highly mobile. In addition, blow flies, flesh flies, muscid flies and black soldier flies have many defenses against the pathogens and toxins found in carrion. These include a protective lining in their midgut, antibiotic-producing microbiota species, and a large number of pattern recognition receptors, lysozymes, antimicrobial peptides and detoxification enzymes. Seasonally, many necrophagous fly species are observed in higher abundance in summer, Trigona worker bees play a similar role to worker bees in the Apis genus; however, along with collecting pollen, nectar, and plant resins, Trigona workers also collect carrion. Although pollen is associated with higher energy value, carrion is preferred by Trigona bees because it is biochemically easier to extract energy from. Cerumen pots are utilized by some Trigona species, such as T. necrophaga, as vesicles to store foodstuff. The foodstuff of T. necrophaga consists of both honey and carrion from vertebrate carcasses. scarab beetles, silphine beetles These sensors are sensitive to dimethyl sulphide and other sulfur-containing compounds emitted by bodies after death. Also, Nicrophorus, Necrodes and other necrophagous silphine beetle species are flight-capable, making it easier for them to reach carrion. Nicrophorus and Dermestes species have many defenses against dietary pathogens and toxins too. These include physical traits such as protective gut linings, antibacterial lectins and lysozymes, mutualistic relationships with microbiota bacteria, and behavioral traits such as preferentially selecting fresh carcasses and smearing carcasses with antibacterial and toxin-degrading exudates. is also an advantage. Regarding food preferences and the logistics of carrion use, N. vespilloides and other burying beetles favor small carcasses (e.g. rodents and small birds) Diving beetles, scarab beetles and water scavenger beetles have all been observed feeding on amphibian carrion (e.g. granular toads and tree frogs). Beetles that feed on human remains are important in forensic science. Terrestrial beetles such as checkered beetles and dermestid beetles colonize bodies in a predictable sequence and have well-characterized life cycles, so they can sometimes be used to estimate time of death. Aquatic beetles are less useful for estimating time of death At Shark Bay in Australia, Nassarius clarus feeds on the carrion of fishes and bivalves. Many marine invertebrates feed on carrion including cephalopods (e.g. Octopus vulgaris), hermit crabs (e.g. Coenobita perlatus), squat lobsters (e.g. Munida tenuimana), star fish (e.g. Asterias rubens), sea anemones (e.g. Actinoscyphia aurelia), amphipods (e.g. Eurythenes gryllus), annelids (e.g. zombie worms), and ribbon worms (e.g. Parborlasia corrugatus). Types of carrion consumed include dead seals, pilchards, jellyfish and tunicates, bones from whale falls, and fishery discards such as whiting and langoustine. Marine necrophages are less useful in forensic science than terrestrial necrophages. This is partly because human deaths occur less frequently in marine settings than terrestrial settings, and partly because human remains are less likely to be recovered in marine settings. In addition, in any aquatic system, there are a large number of environmental and biological factors that can confound calculation of minimum post-mortem interval. These include current and wave action, water temperature, oxygen concentration, and a greater diversity of necrophagous organisms colonizing the remains. == Vertebrates ==

Vultures '') surrounding a mammalian carcass. Many vulture species are obligately necrophagous including the bearded vulture, black vulture, cinereous vulture, Eurasian griffon, Himalayan vulture, king vulture and turkey vulture. but bearded vultures feed on bones and bone marrow. In addition to eating carrion, Egyptian vultures feed on small live animals such as turtles, eggs and rotting fruit. Vultures have many adaptations that help them detect, locate and consume carrion. For example, all vultures have keen eyesight, In addition, gliding flight enables vultures to cover long distances to reach carrion, and strong immune defenses protect vultures from pathogens in carrion. Some human activities have had an adverse impact on vultures in Sicily, and other countries. For example, changes in farming practices such as the indoor raising of cattle and incineration or burial of cattle carcasses have reduced food availability for Eurasian griffon vultures. Coyotes, wolves and other canids (Canis latrans) feeding on pronghorn carrion. Many canids feed opportunistically on carrion. Examples include foxes such as the Arctic fox, corsac fox, gray fox, kit fox and red fox, hyenas such as the brown hyena, spotted hyena and striped hyena, black-backed jackals and golden jackals, as well as coyotes, culpeos, dingoes, gray wolves, Pampas zorros, and raccoon dogs. Types of carrion fed upon ranges from dead wildlife and dead livestock to abandoned predator kills and hunting discards. Anti-botulinum antibodies are an additional antibacterial defense detected in coyotes. Pademelon carrion is eaten frequently by Australian necrophages as pademelons are common in farming areas there, and often end up as roadkill. Brushtail possums eat carrion mostly in winter. This may be because there is less competition from necrophagous insects in winter, or because other food items such as leaves and fruit are more difficult to find. Quolls are also thought to scavenge mostly in winter, perhaps because they are hungriest in winter or because carrion is more readily available in winter. and can detect carrion from long distances. Hagfish are also highly mobile and can arrive at carcasses within minutes or hours of an animal’s death. Immune defenses such as lysozyme-containing slime and antimicrobial proteins (e.g. myxinidin) are thought to protect hagfish from microbial pathogens. ==Current roles and uses==

Maggot therapy in medical packaging. In maggot debridement therapy, sterile, medical-grade larvae of the necrophagous fly Lucilia sericata are used to eliminate necrotic (dead) tissue from non-healing skin and soft-tissue wounds. This is important as dead tissue can facilitate bacterial growth, impede wound healing, and reduce the effectiveness of topical medications. Physicians may administer the fly larvae directly to skin and soft tissue wounds or indirectly within a sealed mesh bag. Larvae then debride the wound by digesting, liquefying and consuming the dead tissue. The US Food and Drug Administration (FDA) have cleared Lucilia sericata larvae for use as a "medical device" in the US to debride several types of wound including pressure ulcers, neuropathic foot ulcers, and nonhealing surgical wounds. This is because these insects rarely deposit eggs in live hosts, they colonize bodies in a predictable sequence following death, and information is available on how long it takes different species to reach different stages of development. temperature, moisture levels, air exposure, geographical region, and other factors, these must all be carefully considered when estimating minimum post-mortem interval. Waste management feeding on duck meat scraps and bones. In some countries, the black soldier fly, Hermetia illucens, is used to process food industry by-products and food waste. Hermetia illucens is a facultative necrophage and can grow on a wide range of decomposing organic substrates including those of animal origin (e.g. abattoir waste), plant origin (e.g. almond hulls), and a mix of both (e.g. meat, fish and vegetable food waste). Fly larvae are grown on this organic waste and then used as livestock feed or fish feed. The frass generated by the larvae can be used as soil fertilizer too. This waste conversion process, known as bioconversion, has several advantages. It reduces the greenhouse gas emissions caused by microbial decomposition of food waste in landfills (e.g. methane), it generates high-quality protein for feeding livestock, and it generates low-cost fertilizer for crop cultivation. Skeleton preparation larvae being used to clean the flesh off a museum specimen. In natural history museums, researchers and curators sometimes wish to study or display animal skeletons. In the Natural History Museum in London, the American Museum of Natural History in New York, and the Australian National Wildlife Collection in Canberra, dermestid beetles are used for skeleton preparation. Dermestid beetles eat hair, skin and flesh, but not bones, and are considered an excellent way of creating clean, professional-grade bone specimens. Sky burial In Tibet and other parts of Asia, necrophagous birds play a central role in a traditional funeral practice called sky burial. Funerals begin with monks chanting mantra and burning juniper incense, and the funeral party carrying the deceased to a large fenced mountain meadow. In this meadow, the body is then cut apart by sky burial masters, and vultures move in to eat it. Other birds and animals, for example magpies and ravens, eat any leftover tissue. ==Other possible uses==

Drug and biomaterial development Necrophages and their microbiotas ("friendly bacteria") produce several molecules of medical interest. These include molecules that can bind to bacterial pathogens (e.g. lectins), inhibit pathogen growth (e.g. chitin, cyclic lipopeptides), and kill pathogens (e.g. antimicrobial peptides, lysozymes). In nature, these molecules are thought to block pathogen entry into the integuments (e.g. skin, cuticle) and circulatory systems (e.g. blood, hemolymph) of necrophages, and enable the immune systems of necrophages to detect, inhibit and kill any pathogens that breach these barriers. China, the USA and other countries to develop these molecules for use in medicine. Possible applications include antimicrobial wound dressings, antibacterial drugs, and drug delivery systems for bacterial infections. Crop development Given the enormous damage that citrus canker, citrus greening, bacterial soft rot and wildfire disease cause to food and cash crops each year, there is interest in developing new plant varieties that are more resistant to infection. One possible solution is to enhance the natural defenses of crops using antimicrobial peptides. Necrophagous insects are a rich source of these peptides, and transgenic research in Japan, the USA, has shown that sarcotoxin IA (from Sarcophaga peregrina) can help protect orange trees and other crops. ==Image and video gallery==

File:Nicrophorus_americanus,_American_Burying_Beetle_(female)_%E2%80%94_taking_flight,_frontal_view.jpg|An American burying beetle about to take flight. File:American carrion beetle.webm|An American carrion beetle feeding on vole carrion. File:Ants cleaning dead snake.jpg|Ants feeding on brown snake carrion. File:Jellyfish & Scavenger snails (3545469708).jpg|Marine snails feeding on jellyfish carrion. File:Kali Gandaki Valley0374.JPG|Himalayan vulture and large-billed crows feeding on a dead mule. File:Marabou storks (Leptoptilos crumenifer) on elephant carcass.jpg|Marabou storks feeding on an elephant carcass. File:A black backed jackal (Canis mesomelas) scavenges on a zebra (Equus quagga) - journal.pone.0060797.g001-C.png|A black-backed jackal feeding on zebra carrion. File:Striped Hyena - Dahod, Gujarat.jpg|A striped hyena feeding on slaughterhouse discards. File:Human Skull being cleaning by Dermestid Beetles.jpg|Dermestid beetles stripping the soft tissue from a human skull. File:Vultures on Lhasa sky burial rock 1.jpg|Gyps vultures at a sky burial in Tibet. ==See also==