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63-406: See text Scutigera is a centipede genus in the scutigeromorph (house centipede) family Scutigeridae , a group of centipedes with long limbs and true compound eyes (which were once thought to be secondary, re-evolved "pseudofacetted eyes"). It compose of more than 30 species , including the most common and well-studied Scutigera coleoptrata . This myriapoda -related article

126-476: A spermatophore for the female to take up. In temperate areas, egg laying occurs in spring and summer. A few parthenogenetic species are known. Females provide parental care, both by curling their bodies around eggs and young, and by grooming them, probably to remove fungi and bacteria. Centipedes are longer-lived than insects; the European Lithobius forficatus may live for 5 to 6 years, and

189-560: A broad range of prey. Common prey items include lumbricid earthworms, dipteran fly larvae, collembolans , and other centipedes. They are carnivorous; study of gut contents suggests that plant material is an unimportant part of their diets, although they eat vegetable matter when starved during laboratory experiments. Species of Scolopendromorph , noticeably members from the genera Scolopendra and Ethmostigmus , are able to hunt for substantial prey items, including large invertebrates and sizable vertebrates, which could be larger than

252-516: A food item, certain large centipedes are consumed in China , usually skewered and grilled or deep fried. They are often seen in street vendors’ stalls in large cities, including Donghuamen and Wangfujing markets in Beijing . Large centipedes are steeped in alcohol to make centipede vodka. Some species of centipedes can be hazardous to humans because of their bite. While a bite to an adult human

315-429: A greater number of segments is required to achieve the same kinds of movements that are possible in vertebrate animals, which have rotational ball-and-socket joints at the base of the fore and hind limbs. The appendages of arthropods may be either biramous or uniramous . A uniramous limb comprises a single series of segments attached end-to-end. A biramous limb, however, branches into two, and each branch consists of

378-424: A median bristle or empodium , meaning the meeting place of the pulvilli. On the underside of the tarsal segments, there frequently are pulvillus-like organs or plantulae . The arolium, plantulae and pulvilli are adhesive organs enabling their possessors to climb smooth or steep surfaces. They all are outgrowths of the exoskeleton and their cavities contain blood. Their structures are covered with tubular tenent hairs,

441-430: A moist microhabitat because they lack the waxy cuticle of insects and arachnids , therefore causing them to rapidly lose water. Accordingly, they avoid direct sunlight by staying under cover or by being active at night . Centipedes have a rounded or flattened head, bearing a pair of antennae at the forward margin. They have a pair of elongated mandibles , and two pairs of maxillae . The first pair of maxillae form

504-451: A role in mating rituals. Because glandular pores occur more frequently on ultimate legs than on the "walking" legs, they may serve a sensory role. They are sometimes used in defensive postures, and some species use them to capture prey, defend themselves against predators, or suspend themselves from objects such as branches, using the legs as pincers. Several species use their ultimate legs upon encountering another centipede, trying to grab

567-636: A series of segments attached end-to-end. The external branch (ramus) of the appendages of crustaceans is known as the exopod or exopodite , while the internal branch is known as the endopod or endopodite . Other structures aside from the latter two are termed exites (outer structures) and endites (inner structures). Exopodites can be easily distinguished from exites by the possession of internal musculature. The exopodites can sometimes be missing in some crustacean groups ( amphipods and isopods ), and they are completely absent in insects. The legs of insects and myriapods are uniramous. In crustaceans,

630-628: A simple tube, with digestive glands attached to the mouthparts. Like insects, centipedes breathe through a tracheal system , typically with a single opening, or spiracle , on each body segment. They excrete waste through a single pair of malpighian tubules . Just as the first pair of legs are modified into forcipules, the back legs are modified into "ultimate legs", also called anal legs, caudal legs, and terminal legs. Their use varies between species, but does not include locomotion. The ultimate legs may be elongated and thin, thickened, or pincer-like. They are frequently sexually dimorphic , and may play

693-422: A tarsal claw. Myriapod legs show a variety of modifications in different groups. In all centipedes, the first pair of legs is modified into a pair of venomous fangs called forcipules. In most millipedes, one or two pairs of walking legs in adult males are modified into sperm-transferring structures called gonopods . In some millipedes, the first leg pair in males may be reduced to tiny hooks or stubs, while in others

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756-415: A variable number of ocelli , sometimes clustered together to form true compound eyes . However, these eyes are only capable of discerning light from dark, and provide no true vision. In some species, the first pair of legs can function as sensory organs, similar to antennae; unlike the antennae of most other invertebrates, these point backwards. An unusual clustering of sensory organs found in some centipedes

819-403: Is anamorphic : more segments and pairs of legs are grown between moults . For example, Scutigera coleoptrata , the house centipede, hatches with only four pairs of legs and in successive moults has 5, 7, 9, 11, 15, 15, 15 and 15 pairs respectively, before becoming a sexually mature adult. Life stages with fewer than 15 pairs of legs are called larval stadia (there are about five stages). After

882-791: Is a stub . You can help Misplaced Pages by expanding it . Centipede Centipedes (from Neo-Latin centi- , "hundred", and Latin pes, pedis , " foot ") are predatory arthropods belonging to the class Chilopoda ( Ancient Greek χεῖλος , kheilos , "lip", and Neo-Latin suffix -poda , "foot", describing the forcipules ) of the subphylum Myriapoda , an arthropod group which includes millipedes and other multi-legged animals. Centipedes are elongated segmented ( metameric ) creatures with one pair of legs per body segment. All centipedes are venomous and can inflict painful stings , injecting their venom through pincer-like appendages known as forcipules or toxicognaths, which are actually modified legs instead of fangs . Despite

945-407: Is adapted for running ( cursorial ), rather than for digging, leaping, swimming, predation, or other similar activities. The legs of most cockroaches are good examples. However, there are many specialized adaptations, including: The embryonic body segments ( somites ) of different arthropods taxa have diverged from a simple body plan with many similar appendages which are serially homologous, into

1008-501: Is epimorphic, meaning that all pairs of legs are developed in the embryonic stages, and offspring do not develop more legs between moults. This clade contains the longest centipedes. In the Geophilomorpha, the number of thoracic segments usually varies within species, often on a geographical basis, and in most cases, females bear more legs than males. The number of leg-bearing segments varies within each order (usually 21 or 23 in

1071-523: Is no longer used. Arachnid legs differ from those of insects by the addition of two segments on either side of the tibia, the patella between the femur and the tibia, and the metatarsus (sometimes called basitarsus) between the tibia and the tarsus (sometimes called telotarsus), making a total of seven segments. The tarsus of spiders have claws at the end as well as a hook that helps with web-spinning. Spider legs can also serve sensory functions, with hairs that serve as touch receptors, as well as an organ on

1134-415: Is the organ of Tömösváry . The organs, at the base of the antennae, consist of a disc-like structure and a central pore, with an encircling of sensitive cells. They are likely used for sensing vibrations, and may provide a weak form of hearing. Forcipules are unique to centipedes. The forcipules are modifications of the first pair of legs (the maxillipeds), forming a pincer -like appendage , just behind

1197-491: Is the fourth section of the typical insect leg. As a rule, the tibia of an insect is slender in comparison to the femur, but it generally is at least as long and often longer. Near the distal end, there is generally a tibial spur, often two or more. In the Apocrita , the tibia of the foreleg bears a large apical spur that fits over a semicircular gap in the first segment of the tarsus. The gap is lined with comb-like bristles, and

1260-483: Is usually very painful and may cause severe swelling, chills, fever , and weakness, it is unlikely to be fatal. Bites can be dangerous to small children and those with allergies to bee stings. The venomous bite of larger centipedes can induce anaphylactic shock in such people. Smaller centipedes are generally incapable of piercing human skin. Even small centipedes that cannot pierce human skin are considered frightening by some humans due to their dozens of legs moving at

1323-465: The Apterygota , the legs of immature specimens are in effect smaller versions of the adult legs. A representative insect leg, such as that of a housefly or cockroach , has the following parts, in sequence from most proximal to most distal : Associated with the leg itself there are various sclerites around its base. Their functions are articular and have to do with how the leg attaches to

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1386-519: The Cerylonidae have four tarsomeres on each tarsus. The distal segment of the typical insect leg is the pretarsus. In the Collembola , Protura and many insect larvae, the pretarsus is a single claw. On the pretarsus most insects have a pair of claws ( ungues , singular unguis ). Between the ungues, a median unguitractor plate supports the pretarsus. The plate is attached to the apodeme of

1449-517: The Cretaceous . The following cladogram shows the position of the Chilopoda within the arthropods as of 2019: inc. horseshoe crabs and spiders [REDACTED] [REDACTED] Chilopoda [REDACTED] millipedes and allies [REDACTED] inc. crustaceans and insects [REDACTED] [REDACTED] Within the myriapods, centipedes are believed to be the first of

1512-629: The IUCN Red List , there are one vulnerable , six endangered , and three critically endangered species of centipede. For example, the Serpent Island centipede ( Scolopendra abnormis) is vulnerable, and Turk's earth centipede (Nothogeophilus turki) and the Seychelles long-legged centipede ( Seychellonema gerlachi) are both endangered. The fossil record of centipedes extends back to 430  million years ago , during

1575-676: The Late Silurian ( Crussolum ), though they are rare throughout the Paleozoic . The Devonian Panther Mountain Formation contains two species of centipede. One is a species of the scutigeromorph Crussolum . The other is Devonobius , which is included in the extinct group Devonobiomorpha. Another Devonian site, the Rhynie chert , also bears Crussolum fossils, and possible scutigeromorph head material. Rhyniognatha , which

1638-623: The Scarabaeidae and Dytiscidae have thoracic legs, but no prolegs. Some insects that exhibit hypermetamorphosis begin their metamorphosis as planidia , specialised, active, legged larvae, but they end their larval stage as legless maggots, for example the Acroceridae . Among the Exopterygota , the legs of larvae tend to resemble those of the adults in general, except in adaptations to their respective modes of life. For example,

1701-446: The most recent common ancestor of extant arthropods but modern arthropods have eight or fewer. It has been argued that the ancestral leg need not have been so complex, and that other events, such as successive loss of function of a Hox -gene , could result in parallel gains of leg segments. In arthropods, each of the leg segments articulates with the next segment in a hinge joint and may only bend in one plane. This means that

1764-470: The Odonata. In parasitic Hymenoptera, the base of the femur has the appearance of a second trochanter. In most insects, the femur is the largest region of the leg; it is especially conspicuous in many insects with saltatorial legs because the typical leaping mechanism is to straighten the joint between the femur and the tibia, and the femur contains the necessary massive bipennate musculature. The tibia

1827-531: The Scolopendromorpha; from 27 to 191 in the Geophilomorpha), but the total number of pairs is always odd, so there are never exactly 100 legs or 100 pairs, despite the group's common name. Centipede segments are developed in two phases. Firstly, the head gives rise to a fixed but odd number of segments, driven by Hox genes as in all arthropods. Secondly, pairs of segments are added at

1890-445: The apices of which are moistened by a glandular secretion. The organs are adapted to apply the hairs closely to a smooth surface so that adhesion occurs through surface molecular forces. Insects control the ungues through muscle tension on a long tendon, the "retractor unguis" or "long tendon". In insect models of locomotion and motor control, such as Drosophila ( Diptera ), locusts ( Acrididae ), or stick insects ( Phasmatodea ),

1953-415: The body of the other centipede. Members of the genus Alipes can stridulate their leaf-like ultimate legs to distract or threaten predators. Rhysida immarginata togoensis makes a faint creaking sound when it swings its ultimate legs. There are many differences between millipedes and centipedes. Both groups of myriapods have long, multi-segmented bodies, many legs, a single pair of antennae, and

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2016-518: The coxa has two lobes where it articulates with the pleuron. The posterior lobe is the meron which is usually the larger part of the coxa. A meron is well developed in Periplaneta, the Isoptera, Neuroptera and Lepidoptera. The trochanter articulates with the coxa but usually is attached rigidly to the femur. In some insects, its appearance may be confusing; for example it has two subsegments in

2079-618: The extant classes to branch from the last common ancestor . The five orders of centipedes are: Craterostigmomorpha , Geophilomorpha , Lithobiomorpha , Scolopendromorpha , and Scutigeromorpha . These orders are united into the clade Chilopoda by the following synapomorphies : The Chilopoda are then split into two clades: the Notostigmophora including the Scutigeromorpha and the Pleurostigmophora including

2142-472: The final two segments are small and legless. Each pair of legs is slightly longer than the pair preceding them, ensuring that they do not overlap, which reduces the chance that they will collide and trip the animal. The last pair of legs may be as much as twice the length of the first pair. The final segment bears a telson , and includes the openings of the reproductive organs. Centipedes mainly use their antennae to seek out their prey. The digestive tract forms

2205-409: The first 50 million years of the clade's evolutionary history, centipede venoms appear to have consisted of a simple cocktail of about four different components, and differentiation into specific venom types appears to have only occurred after the currently recognized five orders had developed. The evolution of the venom includes horizontal gene transfer , involving bacteria, fungi and oomycetes . As

2268-408: The first antennae are uniramous, but the second antennae are biramous, as are the legs in most species. For a time, possession of uniramous limbs was believed to be a shared, derived character , so uniramous arthropods were grouped into a taxon called Uniramia . It is now believed that several groups of arthropods evolved uniramous limbs independently from ancestors with biramous limbs, so this taxon

2331-511: The first pair may be enlarged. Insects and their relatives are hexapods, having six legs, connected to the thorax , each with five components. In order from the body they are the coxa, trochanter, femur, tibia, and tarsus. Each is a single segment, except the tarsus which can be from three to seven segments, each referred to as a tarsomere . Except in species in which legs have been lost or become vestigial through evolutionary adaptation, adult insects have six legs, one pair attached to each of

2394-475: The flexor muscle of the ungues. In the Neoptera , the parempodia are a symmetrical pair of structures arising from the outside (distal) surface of the unguitractor plate between the claws. It is present in many Hemiptera and almost all Heteroptera . Usually, the parempodia are bristly (setiform), but in a few species they are fleshy. Sometimes the parempodia are reduced in size so as to almost disappear. Above

2457-431: The full complement of legs is achieved, the now postlarval stadia (about five more stages) develop gonopods, sensory pores, more antennal segments, and more ocelli. All mature lithobiomorph centipedes have 15 leg-bearing segments. The Craterostigmomorpha only have one phase of anamorphosis, with embryos having 12 pairs, and adults 15. The clade Epimorpha, consisting of the orders Geophilomorpha and Scolopendromorpha ,

2520-402: The head. Forcipules are not oral mouthparts , though they are used to subdue prey by injecting venom and gripping the prey animal. Venom glands run through a tube, from inside the head to the tip of each forcipule. Behind the head, the body consists of at least fifteen segments. Most of the segments bear a single pair of legs; the maxillipeds project forward from the first body segment, while

2583-567: The insect cleans its antennae by drawing them through. The ancestral tarsus was a single segment and in the extant Protura , Diplura and certain insect larvae the tarsus also is single-segmented. Most modern insects have tarsi divided into subsegments (tarsomeres), usually about five. The actual number varies with the taxon , which may be useful for diagnostic purposes. For example, the Pterogeniidae characteristically have 5-segmented fore- and mid-tarsi, but 4-segmented hind tarsi, whereas

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2646-471: The legs of larval insects, particularly in the Endopterygota , vary more than in the adults. As mentioned, some have prolegs as well as "true" thoracic legs. Some have no externally visible legs at all (though they have internal rudiments that emerge as adult legs at the final ecdysis ). Examples include the maggots of flies or grubs of weevils . In contrast, the larvae of other Coleoptera , such as

2709-470: The legs of most immature Ephemeroptera are adapted to scuttling beneath underwater stones and the like, whereas the adults have more gracile legs that are less of a burden during flight. Again, the young of the Coccoidea are called "crawlers" and they crawl around looking for a good place to feed, where they settle down and stay for life. Their later instars have no functional legs in most species. Among

2772-408: The long tendon courses through the tarsus and tibia before reaching the femur. Tension on the long tendon is controlled by two muscles, one in the femur and one in the tibia, which can operate differently depending on how the leg is bent. Tension on the long tendon controls the claw, but also bends the tarsus and likely affects its stiffness during walking. The typical thoracic leg of an adult insect

2835-454: The lower lip, and bear short palps . The first pair of limbs stretch forward from the body over the mouth. These limbs, or forcipules, end in sharp claws and include venom glands that help the animal to kill or paralyze its prey. Their size ranges from a few millimetres in the smaller lithobiomorphs and geophilomorphs to about 30 cm (12 in) in the largest scolopendromorphs . Many species of centipedes lack eyes, but some possess

2898-476: The main exoskeleton of the insect. Such sclerites differ considerably between unrelated insects. The coxa is the proximal segment and functional base of the leg. It articulates with the pleuron and associated sclerites of its thoracic segment, and in some species it articulates with the edge of the sternite as well. The homologies of the various basal sclerites are open to debate. Some authorities suggest that they derive from an ancestral subcoxa. In many species,

2961-623: The myriapod itself. For instance, Scolopendra gigantea (the Amazonian giant centipede) preys on tarantulas , scorpions , lizards , frogs , birds , mice , snakes , and even bats , catching them in midflight. Three species ( Scolopendra cataracta , S. paradoxa , and S. alcyona ) are amphibious, believed to hunt aquatic or amphibious invertebrates. Many larger animals prey upon centipedes, such as mongooses , mice , salamanders , beetles and some specialist snake species. They form an important item of diet for many species and

3024-425: The name, no species of centipede has exactly 100 legs; the number of pairs of legs is an odd number that ranges from 15 pairs to 191 pairs. Centipedes are predominantly generalist carnivorous , hunting for a variety of prey items that can be overpowered. They have a wide geographical range, which can be found in terrestrial habitats from tropical rainforests to deserts . Within these habitats, centipedes require

3087-572: The naming system used in the other groups. They are: coxa, basis, ischium, merus, carpus, propodus, and dactylus. In some groups, some of the limb segments may be fused together. The claw ( chela ) of a lobster or crab is formed by the articulation of the dactylus against an outgrowth of the propodus. Crustacean limbs also differ in being biramous, whereas all other extant arthropods have uniramous limbs. Myriapods ( millipedes , centipedes and their relatives) have seven-segmented walking legs, comprising coxa, trochanter, prefemur, femur, tibia, tarsus, and

3150-641: The other four orders. The following physical and developmental traits can be used to separate members of the Pleurostigmomorpha from Notostigmomorpha: It was previously believed that Chilopoda was split into Anamorpha (Lithobiomorpha and Scutigeromorpha) and Epimorpha (Geophilomorpha and Scolopendromorpha), based on developmental modes, with the relationship of the Craterostigmomorpha being uncertain. Recent phylogenetic analyses using combined molecular and morphological characters supports

3213-450: The presence of postantennal organs . Centipedes have one pair of legs per segment, while millipedes have two. Their heads differ in that millipedes have short, elbowed antennae , a pair of robust mandibles and a single pair of maxillae fused into a lip; centipedes have long, threadlike antennae, a pair of small mandibles, two pairs of maxillae and a pair of large venom claws. Centipede reproduction does not involve copulation. Males deposit

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3276-456: The previous phylogeny. The Epimorpha still exist as a monophyletic group within the Pleurostigmophora, but the Anamorpha are paraphyletic , as shown in the cladogram: Scutigeromorpha [REDACTED] Lithobiomorpha [REDACTED] Craterostigmomorpha [REDACTED] Scolopendromorpha [REDACTED] Geophilomorpha [REDACTED] All centipedes are venomous . Over

3339-507: The same structure as modern adult insect legs, and there has been a great deal of debate as to whether they are homologous with them. Current evidence suggests that they are indeed homologous up to a very primitive stage in their embryological development, but that their emergence in modern insects was not homologous between the Lepidoptera and Symphyta . Such concepts are pervasive in current interpretations of phylogeny. In general,

3402-401: The same time and their tendency to dart swiftly out of the darkness towards one's feet. A 19th-century Tibetan poet warned his fellow Buddhists , "if you enjoy frightening others, you will be reborn as a centipede." Arthropod leg Homologies of leg segments between groups are difficult to prove and are the source of much argument. Some authors posit up to eleven segments per leg for

3465-447: The secretions of Geophilus vittatus are sticky and odorous, and contain hydrogen cyanide. The giant desert centipede of Arizona, Scolopendra polymorpha , has a black head and tail, and an orange body; this conspicuous pattern may be aposematic , an honest signal of the animal's toxicity. Many species raise and splay their ultimate legs and display the spines found on the legs in a defensive threat posture. Because centipedes lack

3528-576: The staple diet of some such as the African ant Amblyopone pluto , which feeds solely on geophilomorph centipedes, and the South African Cape black-headed snake Aparallactus capensis . Some Geophilomorph, Lithobiomorph, and Scolopendromorph centipedes produce sticky, toxic secretions to defend themselves. The various secretions ward off or entangle predators. Scolopendromorph secretions contain hydrogen cyanide . Among Geophilomorphs,

3591-636: The tail (posterior) end by the creation of a prepattern unit, a double segment, which is then always divided into two. The repeated creation of these prepattern units is driven by an oscillator clock, implemented with the Notch signalling pathway . The segments are homologous with the legs of other arthropods such as trilobites ; it would be sufficient for the Notch clock to run faster , as it does in snakes , to create more legs. Centipedes are predominantly generalist predators, which means they are adapted to eat

3654-529: The tarsus that serves as a humidity receptor, known as the tarsal organ . The situation is identical in scorpions , but with the addition of a pre-tarsus beyond the tarsus. The claws of the scorpion are not truly legs, but are pedipalps , a different kind of appendage that is also found in spiders and is specialised for predation and mating. In Limulus , there are no metatarsi or pretarsi, leaving six segments per leg. The legs of crustaceans are divided primitively into seven segments, which do not follow

3717-438: The three segments of the thorax. They have paired appendages on some other segments, in particular, mouthparts , antennae and cerci , all of which are derived from paired legs on each segment of some common ancestor . Some larval insects do however have extra walking legs on their abdominal segments; these extra legs are called prolegs . They are found most frequently on the larvae of moths and sawflies. Prolegs do not have

3780-497: The unguitractor plate, the pretarsus expands forward into a median lobe, the arolium . Webspinners ( Embioptera ) have an enlarged basal tarsomere on each of the front legs, containing the silk -producing glands. Under their pretarsi, members of the Diptera generally have paired lobes or pulvilli, meaning "little cushions". There is a single pulvillus below each unguis. The pulvilli often have an arolium between them or otherwise

3843-510: The waxy water-resistant cuticle of other arthropods, they are more susceptible to water loss via evaporation. Thus, centipedes are most commonly found in high-humidity environments to avoid dehydration, and are mostly nocturnal . Centipedes live in many different habitats including in soil and leaf litter; they are found in environments as varied as tropical rain forests, deserts, and caves. Some geophilomorphs are adapted to littoral habitats, where they feed on barnacles . According to

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3906-451: The wide-ranging Scolopendra subspinipes can live for over 10 years. The combination of a small number of eggs laid, long gestation period, and long time of development to reproduction has led authors to label lithobiomorph centipedes as K-selected . Centipedes grow their legs at different points in their development. In the primitive condition, seen in the orders Lithobiomorpha , Scutigeromorpha , and Craterostigmomorpha , development

3969-582: Was once thought to be the oldest insect fossil, is also found in the Rhynie Chert. Three species, one scutigeromorph ( Latzelia ) and two scolopendromorphs ( Mazoscolopendra and the poorly known Palenarthrus ), have been described from the Mazon Creek fossil beds , which are Carboniferous , 309–307 mya. More species appear in the Mesozoic , including scolopendromorphs and scutigeromorphs in

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