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76-500: Anostraca is one of the four orders of crustaceans in the class Branchiopoda ; its members are referred to as fairy shrimp . They live in vernal pools and hypersaline lakes across the world, and they have even been found in deserts , ice-covered mountain lakes, and Antarctic ice. They are usually 6–25 mm (0.24–0.98 in) long (exceptionally up to 170 mm or 6.7 in). Most species have 20 body segments, bearing 11 pairs of leaf-like phyllopodia (swimming legs), and

152-461: A cohors (plural cohortes ). Some of the plant families still retain the names of Linnaean "natural orders" or even the names of pre-Linnaean natural groups recognized by Linnaeus as orders in his natural classification (e.g. Palmae or Labiatae ). Such names are known as descriptive family names. In the field of zoology , the Linnaean orders were used more consistently. That is,

228-455: A mutation (the deletion of two nucleotides ) that inactives it. These changes are explained by the fact that its prey does not need to be subdued. Several groups of predatory fish have the ability to detect, track, and sometimes, as in the electric ray , to incapacitate their prey by sensing and generating electric fields . The electric organ is derived from modified nerve or muscle tissue. Physiological adaptations to predation include

304-418: A better choice. If it chooses pursuit, its physical capabilities determine the mode of pursuit (e.g., ambush or chase). Having captured the prey, it may also need to expend energy handling it (e.g., killing it, removing any shell or spines, and ingesting it). Predators have a choice of search modes ranging from sit-and-wait to active or widely foraging . The sit-and-wait method is most suitable if

380-851: A broad range of taxa including arthropods. They are common among insects, including mantids, dragonflies , lacewings and scorpionflies . In some species such as the alderfly , only the larvae are predatory (the adults do not eat). Spiders are predatory, as well as other terrestrial invertebrates such as scorpions ; centipedes ; some mites , snails and slugs ; nematodes ; and planarian worms . In marine environments, most cnidarians (e.g., jellyfish , hydroids ), ctenophora (comb jellies), echinoderms (e.g., sea stars , sea urchins , sand dollars , and sea cucumbers ) and flatworms are predatory. Among crustaceans , lobsters , crabs , shrimps and barnacles are predators, and in turn crustaceans are preyed on by nearly all cephalopods (including octopuses , squid and cuttlefish ). Seed predation

456-570: A distinct rank of biological classification having its own distinctive name (and not just called a higher genus ( genus summum )) was first introduced by the German botanist Augustus Quirinus Rivinus in his classification of plants that appeared in a series of treatises in the 1690s. Carl Linnaeus was the first to apply it consistently to the division of all three kingdoms of nature (then minerals , plants , and animals ) in his Systema Naturae (1735, 1st. Ed.). For plants, Linnaeus' orders in

532-473: A fairy shrimp is elongated and divided into segments. The whole animal is typically 6–25 millimetres (0.24–0.98 in) long, but one species, Branchinecta gigas does not reach sexual maturity until it reaches 50 mm (2.0 in) long, and can grow to 170 mm (6.7 in) long. The exoskeleton is thin and flexible, and lacks any sign of a carapace . The body can be divided into three distinct parts ( tagmata ) – head, thorax and abdomen. The head

608-582: A food trap, mechanical stimulation, and electrical impulses to eventually catch and consume its prey. Some carnivorous fungi catch nematodes using either active traps in the form of constricting rings, or passive traps with adhesive structures. Many species of protozoa ( eukaryotes ) and bacteria ( prokaryotes ) prey on other microorganisms; the feeding mode is evidently ancient, and evolved many times in both groups. Among freshwater and marine zooplankton , whether single-celled or multi-cellular, predatory grazing on phytoplankton and smaller zooplankton

684-477: A huge gulp of water and filtering it through their feathery baleen plates. Pursuit predators may be social , like the lion and wolf that hunt in groups, or solitary. Once the predator has captured the prey, it has to handle it: very carefully if the prey is dangerous to eat, such as if it possesses sharp or poisonous spines, as in many prey fish. Some catfish such as the Ictaluridae have spines on

760-725: A kill, and the coyote can be either solitary or social. Other solitary predators include the northern pike, wolf spiders and all the thousands of species of solitary wasps among arthropods, and many microorganisms and zooplankton . Under the pressure of natural selection , predators have evolved a variety of physical adaptations for detecting, catching, killing, and digesting prey. These include speed, agility, stealth, sharp senses, claws, teeth, filters, and suitable digestive systems. For detecting prey , predators have well-developed vision , smell , or hearing . Predators as diverse as owls and jumping spiders have forward-facing eyes, providing accurate binocular vision over

836-539: A long distance, sometimes for hours at a time. The method is used by human hunter-gatherers and by canids such as African wild dogs and domestic hounds. The African wild dog is an extreme persistence predator, tiring out individual prey by following them for many miles at relatively low speed. A specialised form of pursuit predation is the lunge feeding of baleen whales . These very large marine predators feed on plankton , especially krill , diving and actively swimming into concentrations of plankton, and then taking

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912-445: A patch and decide whether to spend time searching for prey in it. This may involve some knowledge of the preferences of the prey; for example, ladybirds can choose a patch of vegetation suitable for their aphid prey. To capture prey, predators have a spectrum of pursuit modes that range from overt chase ( pursuit predation ) to a sudden strike on nearby prey ( ambush predation ). Another strategy in between ambush and pursuit

988-425: A powerful selective effect on prey, and the prey develop antipredator adaptations such as warning coloration , alarm calls and other signals , camouflage , mimicry of well-defended species, and defensive spines and chemicals. Sometimes predator and prey find themselves in an evolutionary arms race , a cycle of adaptations and counter-adaptations. Predation has been a major driver of evolution since at least

1064-785: A predator, while small prey might prove hard to find and in any case provide less of a reward. This has led to a correlation between the size of predators and their prey. Size may also act as a refuge for large prey. For example, adult elephants are relatively safe from predation by lions, but juveniles are vulnerable. Members of the cat family such as the snow leopard (treeless highlands), tiger (grassy plains, reed swamps), ocelot (forest), fishing cat (waterside thickets), and lion (open plains) are camouflaged with coloration and disruptive patterns suiting their habitats. In aggressive mimicry , certain predators, including insects and fishes, make use of coloration and behaviour to attract prey. Female Photuris fireflies , for example, copy

1140-421: A preferred target is scarce. When prey have a clumped (uneven) distribution, the optimal strategy for the predator is predicted to be more specialized as the prey are more conspicuous and can be found more quickly; this appears to be correct for predators of immobile prey, but is doubtful with mobile prey. In size-selective predation, predators select prey of a certain size. Large prey may prove troublesome for

1216-820: A relatively narrow field of view, whereas prey animals often have less acute all-round vision. Animals such as foxes can smell their prey even when it is concealed under 2 feet (60 cm) of snow or earth. Many predators have acute hearing, and some such as echolocating bats hunt exclusively by active or passive use of sound. Predators including big cats , birds of prey , and ants share powerful jaws, sharp teeth, or claws which they use to seize and kill their prey. Some predators such as snakes and fish-eating birds like herons and cormorants swallow their prey whole; some snakes can unhinge their jaws to allow them to swallow large prey, while fish-eating birds have long spear-like beaks that they use to stab and grip fast-moving and slippery prey. Fish and other predators have developed

1292-478: A significant amount of energy, to locate each food patch. For example, the black-browed albatross regularly makes foraging flights to a range of around 700 kilometres (430 miles), up to a maximum foraging range of 3,000 kilometres (1,860 miles) for breeding birds gathering food for their young. With static prey, some predators can learn suitable patch locations and return to them at intervals to feed. The optimal foraging strategy for search has been modelled using

1368-406: A small animal, gulping the prey in an extremely rapid movement when it is within range. Many smaller predators such as the box jellyfish use venom to subdue their prey, and venom can also aid in digestion (as is the case for rattlesnakes and some spiders ). The marbled sea snake that has adapted to egg predation has atrophied venom glands, and the gene for its three finger toxin contains

1444-523: A smaller area. For example, when mixed flocks of birds forage, the birds in front flush out insects that are caught by the birds behind. Spinner dolphins form a circle around a school of fish and move inwards, concentrating the fish by a factor of 200. By hunting socially chimpanzees can catch colobus monkeys that would readily escape an individual hunter, while cooperating Harris hawks can trap rabbits. Predators of different species sometimes cooperate to catch prey. In coral reefs , when fish such as

1520-440: A variety of defences including the ability to hear the echolocation calls. Many pursuit predators that run on land, such as wolves, have evolved long limbs in response to the increased speed of their prey. Their adaptations have been characterized as an evolutionary arms race , an example of the coevolution of two species. In a gene centered view of evolution , the genes of predator and prey can be thought of as competing for

1596-550: Is Branchinecta gaini from the Antarctic Peninsula , while the altitude record is held by B. brushi , which lives at 5,930 metres (19,460 ft) in the Chilean Andes . Other genera, such as Streptocephalus , occur in deserts throughout the world. Anostracans swim gracefully by movements of their phyllopodia (thoracic appendages) in a metachronal rhythm . When swimming, the animal's ventral side

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1672-491: Is Haltinnaias from the late Devonian ( Famennian ) Strud locality of Belgium, around 365 million years old. Some studies point to fossils resembling fairy shrimp in the Upper Cambrian, specifically the oldest known branchiopod fossil, Rehbachiella kinnekullensis , from Orsten marine deposits. Despite its seeming resemblance to modern fairy shrimp, this fossil is still considered by most to be an outlying member of

1748-477: Is ballistic interception , where a predator observes and predicts a prey's motion and then launches its attack accordingly. Ambush or sit-and-wait predators are carnivorous animals that capture prey by stealth or surprise. In animals, ambush predation is characterized by the predator's scanning the environment from a concealed position until a prey is spotted, and then rapidly executing a fixed surprise attack. Vertebrate ambush predators include frogs, fish such as

1824-494: Is common, and found in many species of nanoflagellates , dinoflagellates , ciliates , rotifers , a diverse range of meroplankton animal larvae, and two groups of crustaceans, namely copepods and cladocerans . To feed, a predator must search for, pursue and kill its prey. These actions form a foraging cycle. The predator must decide where to look for prey based on its geographical distribution; and once it has located prey, it must assess whether to pursue it or to wait for

1900-629: Is detected, the predator assesses whether to attack it. This may involve ambush or pursuit predation , sometimes after stalking the prey. If the attack is successful, the predator kills the prey, removes any inedible parts like the shell or spines, and eats it. Predators are adapted and often highly specialized for hunting, with acute senses such as vision , hearing , or smell . Many predatory animals , both vertebrate and invertebrate , have sharp claws or jaws to grip, kill, and cut up their prey. Other adaptations include stealth and aggressive mimicry that improve hunting efficiency. Predation has

1976-628: Is morphologically distinct from the thorax. It bears two compound eyes on prominent stalks, and two pairs of antennae . The first pair of antennae are small, usually unsegmented, and uniramous. The second pair are long and cylindrical in females, but in males they are enlarged and specialised for holding the female during mating . In some groups, males have an additional frontal appendage. The thorax of most anostracans has 13 segments (19 in Polyartemiella and 21 in Polyartemia ). All but

2052-732: Is normally uppermost (often described as swimming "upside-down"). They filter food indiscriminately from the water as they swim, but also scrape algae and other organic materials from solid surfaces, for which they turn to have their ventral side against the food surface. Another important aspect of the fairy shrimp’s life cycle is their universal ability to enter diapause, a state of biological dormancy where growth and metabolism are arrested, as an egg (or cyst). This trait assists in both species' dispersal and in overcoming adverse environmental conditions. Once dormant, these cysts can withstand conditions as harsh and diverse as droughts, frosts, hypersalinity, complete desiccation, exposure to UV radiation and

2128-518: Is restricted to mammals, birds, and insects but is found in almost all terrestrial ecosystems. Egg predation includes both specialist egg predators such as some colubrid snakes and generalists such as foxes and badgers that opportunistically take eggs when they find them. Some plants, like the pitcher plant , the Venus fly trap and the sundew , are carnivorous and consume insects . Methods of predation by plants varies greatly but often involves

2204-430: Is size. Prey that is too small may not be worth the trouble for the amount of energy it provides. Too large, and it may be too difficult to capture. For example, a mantid captures prey with its forelegs and they are optimized for grabbing prey of a certain size. Mantids are reluctant to attack prey that is far from that size. There is a positive correlation between the size of a predator and its prey. A predator may assess

2280-413: Is the most diverse of the four orders of Branchiopoda. It comprises around 313 species, grouped into 26 genera in eight families: Fairy Shrimp have been a student favorite to be the mascot of UC Merced . There had been several efforts to make this animal the official mascot of the campus, but in 2001 the bobcat was chosen instead. Fairy shrimp had also been the focus of a challenge to the location of where

2356-533: Is usually written with a capital letter. For some groups of organisms, their orders may follow consistent naming schemes . Orders of plants , fungi , and algae use the suffix -ales (e.g. Dictyotales ). Orders of birds and fishes use the Latin suffix -iformes meaning 'having the form of' (e.g. Passeriformes ), but orders of mammals and invertebrates are not so consistent (e.g. Artiodactyla , Actiniaria , Primates ). For some clades covered by

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2432-456: The Cambrian period. At the most basic level, predators kill and eat other organisms. However, the concept of predation is broad, defined differently in different contexts, and includes a wide variety of feeding methods; moreover, some relationships that result in the prey's death are not necessarily called predation. A parasitoid , such as an ichneumon wasp , lays its eggs in or on its host;

2508-528: The International Code of Zoological Nomenclature , several additional classifications are sometimes used, although not all of these are officially recognized. In their 1997 classification of mammals , McKenna and Bell used two extra levels between superorder and order: grandorder and mirorder . Michael Novacek (1986) inserted them at the same position. Michael Benton (2005) inserted them between superorder and magnorder instead. This position

2584-815: The Systema Naturae and the Species Plantarum were strictly artificial, introduced to subdivide the artificial classes into more comprehensible smaller groups. When the word ordo was first consistently used for natural units of plants, in 19th-century works such as the Prodromus Systematis Naturalis Regni Vegetabilis of Augustin Pyramus de Candolle and the Genera Plantarum of Bentham & Hooker, it indicated taxa that are now given

2660-465: The angel shark , the northern pike and the eastern frogfish . Among the many invertebrate ambush predators are trapdoor spiders and Australian Crab spiders on land and mantis shrimps in the sea. Ambush predators often construct a burrow in which to hide, improving concealment at the cost of reducing their field of vision. Some ambush predators also use lures to attract prey within striking range. The capturing movement has to be rapid to trap

2736-455: The common garter snake has developed a resistance to the toxin in the skin of the rough-skinned newt . Predators affect their ecosystems not only directly by eating their own prey, but by indirect means such as reducing predation by other species, or altering the foraging behaviour of a herbivore, as with the biodiversity effect of wolves on riverside vegetation or sea otters on kelp forests. This may explain population dynamics effects such as

2812-475: The grouper and coral trout spot prey that is inaccessible to them, they signal to giant moray eels , Napoleon wrasses or octopuses . These predators are able to access small crevices and flush out the prey. Killer whales have been known to help whalers hunt baleen whales . Social hunting allows predators to tackle a wider range of prey, but at the risk of competition for the captured food. Solitary predators have more chance of eating what they catch, at

2888-465: The marginal value theorem . Search patterns often appear random. One such is the Lévy walk , that tends to involve clusters of short steps with occasional long steps. It is a good fit to the behaviour of a wide variety of organisms including bacteria, honeybees, sharks and human hunter-gatherers. Having found prey, a predator must decide whether to pursue it or keep searching. The decision depends on

2964-709: The ability of predatory bacteria to digest the complex peptidoglycan polymer from the cell walls of the bacteria that they prey upon. Carnivorous vertebrates of all five major classes (fishes, amphibians, reptiles, birds, and mammals) have lower relative rates of sugar to amino acid transport than either herbivores or omnivores, presumably because they acquire plenty of amino acids from the animal proteins in their diet. To counter predation, prey have evolved defences for use at each stage of an attack. They can try to avoid detection, such as by using camouflage and mimicry . They can detect predators and warn others of their presence. If detected, they can try to avoid being

3040-733: The ability to crush or open the armoured shells of molluscs. Many predators are powerfully built and can catch and kill animals larger than themselves; this applies as much to small predators such as ants and shrews as to big and visibly muscular carnivores like the cougar and lion . Predators are often highly specialized in their diet and hunting behaviour; for example, the Eurasian lynx only hunts small ungulates . Others such as leopards are more opportunistic generalists, preying on at least 100 species. The specialists may be highly adapted to capturing their preferred prey, whereas generalists may be better able to switch to other prey when

3116-674: The ancestral marine Branchiopoda rather than an actual fairy shrimp. The monophyly of this order is well supported, and the scientific community has reached consensus that Anostraca was the first group to branch off from the Branchiopoda. The radiation hypothesis championing rapid spread and colonization during the Gondwana fragmentation closely echoes the current distribution of the order. Presently, Anostraca are found on all seven continents. Most extant genera have restricted geographical distributions. Only three genera are widespread across

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3192-584: The assault. When animals eat seeds ( seed predation or granivory ) or eggs ( egg predation ), they are consuming entire living organisms, which by definition makes them predators. Scavengers , organisms that only eat organisms found already dead, are not predators, but many predators such as the jackal and the hyena scavenge when the opportunity arises. Among invertebrates, social wasps such as yellowjackets are both hunters and scavengers of other insects. While examples of predators among mammals and birds are well known, predators can be found in

3268-684: The back (dorsal) and belly (pectoral) which lock in the erect position; as the catfish thrashes about when captured, these could pierce the predator's mouth, possibly fatally. Some fish-eating birds like the osprey avoid the danger of spines by tearing up their prey before eating it. In social predation, a group of predators cooperates to kill prey. This makes it possible to kill creatures larger than those they could overpower singly; for example, hyenas , and wolves collaborate to catch and kill herbivores as large as buffalo, and lions even hunt elephants. It can also make prey more readily available through strategies like flushing of prey and herding it into

3344-452: The body lacks a carapace . They swim "upside-down" and feed by filtering organic particles from the water or by scraping algae from surfaces, with the exception of Branchinecta gigas , or "giant fairy shrimp", which is itself a predator of other species of anostracans. They are an important food for many birds and fish, and some are cultured and harvested for use as fish food. There are 300 species spread across 8 families . The body of

3420-538: The campus would be built because of their nearby vernal pool habitat. Order (biology) What does and does not belong to each order is determined by a taxonomist , as is whether a particular order should be recognized at all. Often there is no exact agreement, with different taxonomists each taking a different position. There are no hard rules that a taxonomist needs to follow in describing or recognizing an order. Some taxa are accepted almost universally, while others are recognized only rarely. The name of an order

3496-416: The costs and benefits involved. A bird foraging for insects spends a lot of time searching but capturing and eating them is quick and easy, so the efficient strategy for the bird is to eat every palatable insect it finds. By contrast, a predator such as a lion or falcon finds its prey easily but capturing it requires a lot of effort. In that case, the predator is more selective. One of the factors to consider

3572-698: The diet of flamingos wherever it can be found. Brine shrimp are used as food for fish and other organisms in aquaria and aquaculture . Their drought-resistant eggs are collected from lakeshores and are stored and transported dry. They hatch readily when submerged in salt water. This is a multimillion-dollar industry, centred on the Great Salt Lake in Utah and San Francisco Bay in California ; adults are collected from Mono Lake and transported frozen. Fairy shrimp are believed to have diverged from

3648-993: The eggs hatch into larvae, which eat the host, and it inevitably dies. Zoologists generally call this a form of parasitism , though conventionally parasites are thought not to kill their hosts. A predator can be defined to differ from a parasitoid in that it has many prey, captured over its lifetime, where a parasitoid's larva has just one, or at least has its food supply provisioned for it on just one occasion. There are other difficult and borderline cases. Micropredators are small animals that, like predators, feed entirely on other organisms; they include fleas and mosquitoes that consume blood from living animals, and aphids that consume sap from living plants. However, since they typically do not kill their hosts, they are now often thought of as parasites. Animals that graze on phytoplankton or mats of microbes are predators, as they consume and kill their food organisms, while herbivores that browse leaves are not, as their food plants usually survive

3724-404: The evolution of mimicry. Avoidance is not necessarily an evolutionary response as it is generally learned from bad experiences with prey. However, when the prey is capable of killing the predator (as can a coral snake with its venom), there is no opportunity for learning and avoidance must be inherited. Predators can also respond to dangerous prey with counter-adaptations. In western North America,

3800-730: The form of urea . Most of the animal's nitrogenous waste is, however, in the form of ammonia , which probably diffuses into the environment through the phyllopodia and gills. Anostracans inhabit inland waters ranging from hypersaline lakes to lakes that are almost devoid of dissolved substances; they are "the most archetypal crustaceans" in ephemeral waters. The relatively large size of fairy shrimp, together with their slow means of locomotion, makes them an easy target for predatory fish and waterfowl . This has led to their distribution being restricted to environments with fewer predators, such as vernal pools , salt lakes and lakes at high altitudes or latitudes. The southernmost recorded fairy shrimp

3876-431: The larvae of coccinellid beetles (ladybirds) , alternate between actively searching and scanning the environment. Prey distributions are often clumped, and predators respond by looking for patches where prey is dense and then searching within patches. Where food is found in patches, such as rare shoals of fish in a nearly empty ocean, the search stage requires the predator to travel for a substantial time, and to expend

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3952-463: The last two are very similar, with a pair of biramous phyllopods (flattened, leaf-like appendages ). The last two segments are fused together, and their appendages are specialised for reproduction. Most anostracans have separate sexes ( gonochorism ), but a few reproduce by parthenogenesis . The abdomen comprises 6 segments without appendages, and a telson , which bears two flattened caudal rami or "cercopods". The head contains two digestive glands and

4028-408: The length of the body, with two ganglia and two transverse commissures in most of the body segments. Gas exchange is thought to take place through the entire body surface, but especially that of the phyllopodia and their associated gills, which may also be responsible for osmotic regulation . Two coiled glands at the bases of the maxillae are used to excrete nitrogenous waste , typically in

4104-429: The light signals of other species, thereby attracting male fireflies, which they capture and eat. Flower mantises are ambush predators; camouflaged as flowers, such as orchids , they attract prey and seize it when it is close enough. Frogfishes are extremely well camouflaged, and actively lure their prey to approach using an esca , a bait on the end of a rod-like appendage on the head, which they wave gently to mimic

4180-529: The main line of Branchiopoda during the Ordovician period, around the same time it is thought they colonized freshwater and estuarine ecosystems. This transition is believed to have resulted from selection pressure to escape predation in the Early Paleozoic seas. Lepidocaris from the early Devonian Rhynie chert is likely a close relative of Anostraca. The oldest known modern-looking ansotracan

4256-708: The orders in the zoology part of the Systema Naturae refer to natural groups. Some of his ordinal names are still in use, e.g. Lepidoptera (moths and butterflies) and Diptera (flies, mosquitoes, midges, and gnats). In virology , the International Committee on Taxonomy of Viruses 's virus classification includes fifteen taxomomic ranks to be applied for viruses , viroids and satellite nucleic acids : realm , subrealm , kingdom , subkingdom, phylum , subphylum , class, subclass, order, suborder, family, subfamily , genus, subgenus , and species. There are currently fourteen viral orders, each ending in

4332-434: The other hand, the fitness cost of a given lost dinner is unpredictable, as the predator may quickly find better prey. In addition, most predators are generalists, which reduces the impact of a given prey adaption on a predator. Since specialization is caused by predator-prey coevolution, the rarity of specialists may imply that predator-prey arms races are rare. It is difficult to determine whether given adaptations are truly

4408-564: The precursor of the currently used International Code of Nomenclature for algae, fungi, and plants . In the first international Rules of botanical nomenclature from the International Botanical Congress of 1905, the word family ( familia ) was assigned to the rank indicated by the French famille , while order ( ordo ) was reserved for a higher rank, for what in the 19th century had often been named

4484-538: The prey an opportunity to escape. Some frogs wait until snakes have begun their strike before jumping, reducing the time available to the snake to recalibrate its attack, and maximising the angular adjustment that the snake would need to make to intercept the frog in real time. Ballistic predators include insects such as dragonflies, and vertebrates such as archerfish (attacking with a jet of water), chameleons (attacking with their tongues), and some colubrid snakes . In pursuit predation, predators chase fleeing prey. If

4560-549: The prey are dense and mobile, and the predator has low energy requirements. Wide foraging expends more energy, and is used when prey is sedentary or sparsely distributed. There is a continuum of search modes with intervals between periods of movement ranging from seconds to months. Sharks, sunfish , Insectivorous birds and shrews are almost always moving while web-building spiders, aquatic invertebrates, praying mantises and kestrels rarely move. In between, plovers and other shorebirds , freshwater fish including crappies , and

4636-413: The prey flees in a straight line, capture depends only on the predator's being faster than the prey. If the prey manoeuvres by turning as it flees, the predator must react in real time to calculate and follow a new intercept path, such as by parallel navigation , as it closes on the prey. Many pursuit predators use camouflage to approach the prey as close as possible unobserved ( stalking ) before starting

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4712-428: The prey's body. However, the "life-dinner" principle of Dawkins and Krebs predicts that this arms race is asymmetric: if a predator fails to catch its prey, it loses its dinner, while if it succeeds, the prey loses its life. The metaphor of an arms race implies ever-escalating advances in attack and defence. However, these adaptations come with a cost; for instance, longer legs have an increased risk of breaking, while

4788-433: The prey, given that the attack is not modifiable once launched. Ballistic interception is the strategy where a predator observes the movement of a prey, predicts its motion, works out an interception path, and then attacks the prey on that path. This differs from ambush predation in that the predator adjusts its attack according to how the prey is moving. Ballistic interception involves a brief period for planning, giving

4864-509: The price of increased expenditure of energy to catch it, and increased risk that the prey will escape. Ambush predators are often solitary to reduce the risk of becoming prey themselves. Of 245 terrestrial members of the Carnivora (the group that includes the cats, dogs, and bears), 177 are solitary; and 35 of the 37 wild cats are solitary, including the cougar and cheetah. However, the solitary cougar does allow other cougars to share in

4940-414: The pursuit. Pursuit predators include terrestrial mammals such as humans, African wild dogs, spotted hyenas and wolves; marine predators such as dolphins, orcas and many predatory fishes, such as tuna; predatory birds (raptors) such as falcons; and insects such as dragonflies . An extreme form of pursuit is endurance or persistence hunting , in which the predator tires out the prey by following it over

5016-502: The rank of family (see ordo naturalis , ' natural order '). In French botanical publications, from Michel Adanson 's Familles naturelles des plantes (1763) and until the end of the 19th century, the word famille (plural: familles ) was used as a French equivalent for this Latin ordo . This equivalence was explicitly stated in the Alphonse Pyramus de Candolle 's Lois de la nomenclature botanique (1868),

5092-678: The rate of selection by resisting gene flow and minimizing phenotypic variation, in turn promoting the stability of the existing, successful phenotype. Anostracans are an important food source for many birds and fish. For example, they provide much of the food for female pintails and mallards in the Prairie Pothole Region of the Great Plains in North America , especially in years when temporary wetlands are abundant. Similarly, Artemia forms an important part of

5168-483: The remnants of the former supercontinent Pangaea : Artemia , Branchinella and Branchinecta , while the remaining genera are found only throughout former Laurasia. This suggests that much of the potential habitat in this supercontinent, now occupied by Anostraca, to have been unoccupied by ecologically similar species, or to have been inhabited by species with less adaptive ability. Studies have found Anostraca capable of rapid colonization and speciation. Anostraca

5244-470: The result of coevolution, where a prey adaptation gives rise to a predator adaptation that is countered by further adaptation in the prey. An alternative explanation is escalation , where predators are adapting to competitors, their own predators or dangerous prey. Apparent adaptations to predation may also have arisen for other reasons and then been co-opted for attack or defence. In some of the insects preyed on by bats, hearing evolved before bats appeared and

5320-460: The small lobate stomach into which they empty. This is connected to a long intestine , which terminates in a short rectum , with the anus located on the telson . The haemocoel of anostracans is pumped by a long, tubular heart , which runs through most of the animal's length. A series of slits allow haemocoel into the heart, which is then pumped out of the anterior opening by peristalsis . The nervous system consists of two nerve cords which run

5396-417: The specialized tongue of the chameleon, with its ability to act like a projectile, is useless for lapping water, so the chameleon must drink dew off vegetation. The "life-dinner" principle has been criticized on multiple grounds. The extent of the asymmetry in natural selection depends in part on the heritability of the adaptive traits. Also, if a predator loses enough dinners, it too will lose its life. On

5472-639: The suffix -virales . Predator Predation is a biological interaction 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

5548-684: The target of an attack, for example, by signalling that they are toxic or unpalatable , by signalling that a chase would be unprofitable, or by forming groups. If they become a target, they can try to fend off the attack with defences such as armour, quills , unpalatability, or mobbing; and they can often escape an attack in progress by startling the predator, playing dead , shedding body parts such as tails, or simply fleeing. Predators and prey are natural enemies, and many of their adaptations seem designed to counter each other. For example, bats have sophisticated echolocation systems to detect insects and other prey, and insects have developed

5624-422: The vacuum of space. It is also the only way for the fairy shrimps to colonize new habitats—facilitated by a variety of conditions including wind, predators, currents—as the soft-bodied adults are unable to leave the freshwater system. Once in diapause, these cysts can remain viable for centuries, and the mixing of system sediment results in the hatching of different aged cysts in each generation. This inbreeding slows

5700-418: Was adopted by Systema Naturae 2000 and others. In botany , the ranks of subclass and suborder are secondary ranks pre-defined as respectively above and below the rank of order. Any number of further ranks can be used as long as they are clearly defined. The superorder rank is commonly used, with the ending -anae that was initiated by Armen Takhtajan 's publications from 1966 onwards. The order as

5776-401: Was used to hear signals used for territorial defence and mating. Their hearing evolved in response to bat predation, but the only clear example of reciprocal adaptation in bats is stealth echolocation. A more symmetric arms race may occur when the prey are dangerous, having spines, quills, toxins or venom that can harm the predator. The predator can respond with avoidance, which in turn drives

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