|Class:|| Chilopoda |
|Orders and families|
Centipedes (from the New Latin prefix centi- , "hundred", and the Latin word pes, pedis , "foot") are predatory arthropods belonging to the class Chilopoda (Ancient Greek χεῖλος , kheilos, lip, and New Latin suffix -poda , "foot", describing the forcipules) of the subphylum Myriapoda, an arthropod group which also includes millipedes and other multi-legged creatures. Centipedes are elongated metameric creatures with one pair of legs per body segment. Most centipedes are generally venomous and can inflict painful bites, injecting their venom through pincer-like appendages known as forcipules. Despite the name, centipedes can have a varying number of legs, ranging from 30 to 354. Centipedes always have an odd number of pairs of legs. Therefore, no centipede has exactly 100 legs. Like spiders and scorpions, centipedes are predominantly carnivorous. :168
Their size can range from a few millimetres in the smaller lithobiomorphs and geophilomorphs to about 30 cm (12 in) in the largest scolopendromorphs. Centipedes can be found in a wide variety of environments. They normally have a drab coloration combining shades of brown and red. Cavernicolous (cave-dwelling) and subterranean species may lack pigmentation, and many tropical scolopendromorphs have bright aposematic colors.
Worldwide, an estimated 8,000 species of centipedes are thought to exist,of which 3,000 have been described. Centipedes have a wide geographical range, even reaching beyond the Arctic Circle. They are found in an array of terrestrial habitats from tropical rainforests to deserts. Within these habitats, centipedes require a moist microhabitat because they lack the waxy cuticle of insects and arachnids, therefore causing them to rapidly lose water. Accordingly, they are found in soil and leaf litter, under stones and dead wood, and inside logs. Centipedes are among the largest terrestrial invertebrate predators, and often contribute significantly to the invertebrate predatory biomass in terrestrial ecosystems.
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 the lower lip, and bear short palps. The first pair of limbs stretch forward from the body to cover the remainder of the mouth. These limbs, or maxillipeds, end in sharp claws and include venom glands that help the animal to kill or paralyze its prey.
Many species of centipedes lack eyes, but some possess a variable number of ocelli, which are sometimes clustered together to form true compound eyes. However, these eyes are only capable of discerning light and dark, and have no true vision. In some species, the first pair of legs at the head end of the centipede acts as sense organs similar to antennae, but unlike the antennae of most other animals, theirs point backwards. Unusual sense organs found in some groups are the organs of Tömösváry. These are located at the base of the antennae, and consist of a disc-like structure with a central pore surrounded by sensory cells. They are probably used for sensing vibrations, and may even provide a sense of hearing.
Forcipules are a unique feature found only in centipedes and in no other arthropods. The forcipules are modifications of the first pair of legs, forming a pincer-like appendage always found just behind the head.Forcipules are not true mouthparts, although they are used in the capture of prey items, injecting venom and holding onto captured prey. Venom glands run through a tube almost to the tip of each forcipule.
Behind the head, the body consists of 15 or more segments. Most of the segments bear a single pair of legs, with the maxillipeds projecting forward from the first body segment, and the final two segments being small and legless. Each pair of legs is slightly longer than the pair immediately in front of it, ensuring that they do not overlap, so reducing the chance that they will collide with each other while moving swiftly. In extreme cases, the last pair of legs may be twice the length of the first pair. The final segment bears a telson and includes the openings of the reproductive organs.
As predators, centipedes mainly use their antennae to seek out their prey. The digestive tract forms 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.
Scolopendra gigantea , also known as the Amazonian giant centipede, is the largest existing species of centipede in the world, reaching over 30 cm (12 in) in length. It is known to eat lizards, frogs, birds, mice, and even bats, catching them in midflight, as well as rodents and spiders.
Centipede reproduction does not involve copulation. Males deposit a spermatophore for the female to take up. In one clade, this spermatophore is deposited in a web, and the male undertakes a courtship dance to encourage the female to engulf his sperm. In other cases, the males just leave them for the females to find. In temperate areas, egg laying occurs in spring and summer, but in subtropical and tropical areas, little seasonality to centipede breeding is apparent. A few species of parthenogenetic centipedes are known.
The Lithobiomorpha and Scutigeromorpha lay their eggs singly in holes in the soil, and the female fills the holes with soil and leaves them. The number of eggs laid ranges from about 10 to 50. Time of development of the embryo to hatching is highly variable and may take from one to a few months. Time of development to reproductive period is highly variable within and among species. For example, it can take 3 years for S. coleoptrata to achieve adulthood, whereas under the right conditions, lithobiomorph species may reach a reproductive period in 1 year. In addition, centipedes are relatively long-lived when compared to insects. For example, the European Lithobius forficatus may live for 5 to 6 years,and 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.
Females of the Geophilomorpha and Scolopendromorpha show far more parental care. The eggs, 15 to 60 in number, are laid in a nest in the soil or in rotten wood. The female stays with the eggs, guarding and cleaning them to protect them from fungi. The female in some species stays with the young after they have hatched, guarding them until they are ready to leave. If disturbed, the female either abandons the eggs or eats them; abandoned eggs tend to fall prey to fungi rapidly. Some species of Scolopendromorpha are matriphagic, meaning the offspring eat their mother.
Little is known of the life history of the Craterostigmomorpha.
Centipedes grow their legs at different points in their development. In the primitive condition, exhibited by the Lithobiomorpha, Scutigeromorpha, and Craterostigmomorpha, development is anamorphic: more 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 before becoming a sexually mature adult. Life stages with fewer than 15 pairs of legs are called larval stadia (about five stages). After the full complement of legs is achieved, the now postlarval stadia (about five stages) develop gonopods, sensory pores, more antennal segments, and more ocelli. All mature lithobiomorph centipedes have 15 leg-bearing segments. 27:
The Craterostigmomorpha only have one phase of anamorphosis, with embryos having 12 pairs, and moultees 15.
The clade Epimorpha, consisting of the orders Geophilomorpha and Scolopendromorpha, exhibits epimorphy: 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; the maximum number of thoracic segments may also vary intraspecifically, often on a geographical basis; in most cases, females bear more legs than males. The number of leg-bearing segments varies widely, from 15 to 191, but the developmental mode of their creation means they are always added in pairs—hence the total number of pairs is always odd.
Centipedes are predominantly generalist predators, which means they have adapted to eat a variety of different available prey. Examination of centipede gut contents suggests that plant material is an unimportant part of their diets, although centipedes have been observed to eat vegetable matter when starved during laboratory experiments. 168:
Centipedes are mostly nocturnal. Studies on their activity rhythms confirm this, although a few observations of centipedes active during the day have been made, and one species, Strigamia chinophila, is diurnal. What centipedes actually eat is not well known because of their cryptic lifestyles and thorough mastication of food. Laboratory feeding trials support that they will feed as generalists, taking almost anything that is soft-bodied and in a reasonable size range. Earthworms may provide the bulk of diets for geophilomorphs, since they burrow through the soil and earthworm bodies would be easily pierced by their venomous claws. Geophilomorphs probably cannot subdue earthworms larger than themselves, so smaller earthworms may be a substantial proportion of their diet.
Scolopendromorphs, given their size, are able to feed on vertebrates, in addition to invertebrates. Springtails may provide a large proportion of lithobiomorph diets. Little is known about scutigeromorph or craterostigmomorph diets. All centipedes are potential intraguild predators. Centipedes and spiders may frequently prey on one another.Two species, Scolopendra cataracta and S. paradoxa are known to be amphibious and are believed to hunt aquatic or amphibious invertebrates.
Many larger animals prey upon centipedes, such as mongooses, mice, salamanders, beetles and snakes. 354–356 They form an important item of diet for many species and 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 . :354–356:
Centipede defences include their speed and venomous forcipules, as well as the secretion of defensive chemicals. Geophilomorph centipedes can secrete sticky substances that generate toxic hydrogen cyanide and benzoic acid from microscopic glands on their undersides. Similarly, lithobiomorph centipedes secrete a sticky substance from glands in the rear-most two pairs of legs.
Water regulation is an important aspect of centipede ecology, since they lose water rapidly in dry conditions and are found in moist microhabitats. Water loss is a result of centipedes lacking a waxy covering of their exoskeleton and excreting waste nitrogen as ammonia, which requires extra water. Centipedes deal with water loss through a variety of adaptations. Geophilomorphs lose water less rapidly than lithobiomorphs, though they have a greater surface area to volume ratio. This may be because geophilomorphs have a more heavily sclerotized pleural membrane. Spiracle shape, size, and ability to constrict also have an influence on rate of water loss. In addition, the number and size of coxal pores may be variables affecting centipede water balance.
Centipedes live in many different habitat types—forest, savannah, prairie, and desert, to name a few. Some geophilomorphs are adapted to littoral habitats, where they feed on barnacles. mg/m2 wet weight. Small geophilomorphs attain highest densities, followed by small lithobiomorphs. Large lithobiomorphs attain densities of 20/m2. One study of scolopendromorphs records Scolopendra morsitans in a Nigerian savannah at a density of 0.16/m2 and a biomass of 140 mg/m2 wet weight.Species of all orders excluding the Craterostigmomorpha have adapted to caves. Centipede densities have been recorded as high as 600/m2 and biomass as high as 500
As a food item, certain large-sized 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.
Also in China, as well as in Laos, Thailand, and Cambodia, large centipedes are kept in liquor for a period of time. This custom is allegedly part of the traditional Chinese medicine. Said to have medicinal properties and to be reinvigorating,the liquor with the centipede submerged in it is consumed as a special drink.
Some species of centipedes can be hazardous to humans because of their bite. While a bite to an adult human 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 nonvenomous centipedes are considered frightening by some humans due to their dozens of legs moving at 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."
|Internal phylogeny of the Chilopoda|
|The upper three groups form the paraphyletic Anamorpha.|
The fossil record of centipedes extends back to, during the Late Silurian. They belong to the subphylum Myriapoda which includes Diplopoda, Symphyla, and Pauropoda. The oldest known fossil land animal, Pneumodesmus newmani , is a myriapod. Being among the earliest terrestrial animals, centipedes were one of the first to fill a fundamental niche as ground level generalist predators in detrital food webs. Today, centipedes are abundant and exist in many harsh habitats.
Within the myriapods, centipedes are believed to be the first of 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 the other four orders. The main difference is that the Notostigmophora have their spiracles located mid-dorsally. 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 the previous phylogeny.The Epimorpha still exist as a monophyletic group within the Pleurostigmophora, but the Anamorpha are paraphyletic.
Geophilomorph centipedes have been used to argue for the developmental constraint of evolution; that the evolvability of a trait, the number of segments in the case of geophilomorph centipedes, was constrained by the mode of development. The geophilomorph centipedes have variable segment numbers within species, yet as with all centipedes, they always have an odd number of pairs of legs. In this taxon, the number of segments ranges from 27 to 191, but is never an even number.
The Scutigeromorpha are anamorphic, reaching 15 leg-bearing segments in length. Also known as house centipedes, they are very fast creatures, and able to withstand falling at great speed: they reach up to 15 body lengths per second when dropped, surviving the fall. They are the only centipede group to retain their original compound eyes, within which a crystalline layer analogous to that seen in chelicerates and insects can be observed. They also bear long and multi-segmented antennae. Adaptation to a burrowing lifestyle has led to the degeneration of compound eyes in other orders; this feature is of great use in phylogenetic analysis.
The group is the sole extant representative of the Notostigmophora, defined by having a single spiracle opening at the posterior of each dorsal plate. The more derived groups bear a plurality of spiracular openings on their sides, and are termed the Pleurostigmophora. Some even have several unpaired spiracles that can be found along the mid-dorsal line and closer to their posterior section of tergites. There are three families: Pselliodidae, Scutigeridae and Scutigerinidae. Pselliodidae includes just a few species in the genus Sphendononema (=Pselliodes), occurring in the Neotropics and tropical Africa. Scutigerinidae, composed of three species in the genus Scutigerina, is restricted to southern Africa and Madagascar. Most scutigeromorphs from other parts of the world belong to the Scutigeridae, which includes two subfamilies, the Scutigerinae and Thereuoneminae.
The Lithobiomorpha, also known as stone centipedes, represent the other main group of anamorphic centipedes; they also reach a mature segment count of 15 trunk segments. This group has lost the compound eyes, and sometimes has no eyes altogether. Instead, its eyes have a single ocellus or a group of ocelli. Its spiracles are paired and can be found laterally. Every leg-bearing segment of this organism has a separate tergite, these alternating in length apart from a pair of long tergites on each of segments 7 and 8. It also has relatively short antennae and legs compared to the Scutigeromorpha. Two families are included, the Henicopidae and Lithobiidae.
The Craterostigmomorpha are the least diverse centipede clade, comprising only two extant species, both in the genus Craterostigmus.Their geographic range is restricted to Tasmania and New Zealand. There is a single ocellus on each side of the head capsule. They have a distinct body plan; their anamorphosis comprises a single stage: in their first moult, they grow from having 12 segments to having 15. Their low diversity and intermediate position between the primitive anamorphic centipedes and the derived Epimorpha has led to them being likened to the platypus. They represent the survivors of a once diverse clade.
Maternal brooding unites the Craterostigmomorpha with the Epimorpha into the clade Phylactometria. This trait is thought to be closely linked with the presence of sternal pores, which secrete sticky or noxious secretions, which mainly serve to repel predators and parasites. The presence of these pores on the Devonian Devonobius permits its inclusion in this clade, allowing its divergence to be dated to.
The Scolopendromorpha, also known as tropical centipedes, possess 21 or 23 body segments (apart from a single species, Scolopendropsis duplicata, which has 39 or 43 segments) with the same number of paired legs. Their antennae have 17 or more segments. The eyes have a fixed number of four ocelli on each side in the family Scolopendridae and one ocellus per side in the genus Mimops (family Mimopidae), but other families are blind. The order comprises the five families Cryptopidae, Scolopendridae, Mimopidae, Scolopocryptopidae, and Plutoniumidae. The only 2 known amphibious centipedes, Scolopendra cataracta and Scolopendra paradoxa belong to this order.
The Geophilomorpha, commonly known as soil centipedes, bear upwards of 27 leg-bearing segments. They are eyeless and blind, and bear spiracles on all leg-bearing segments—in contrast to other groups, which usually bear them only on their 3rd, 5th, 8th, 10th, 12th, and 14th segments—a "mid-body break", accompanied by a change in tagmatic shape, occurring roughly at the interchange from odd to even segments. This group, the most diverse at 1260 species, also contains the largest and leggiest specimens at 27 or more pairs of legs. They also have 14–segmented antennae. The group includes at least seven families: Mecistocephalidae, Geophilidae (including the former Linotaeniidae, Dignathodontidae and Macronicophilidae), Oryidae, Himantariidae, Schendylidae (including the former Ballophilidae), Zelanophilidae, and Gonibregmatidae (including the former Neogeophilidae and Eriphantidae).
|Scientific name||Common name|
|Alipes grandidieri||feather-tail centipede|
|Ethmostigmus trigonopodus||blue ring centipede|
|Lithobius forficatus||stone centipede|
|Pachymerium ferrugineum||earth centipede|
|Scolopendra galapagoensis||Galápagos centipede|
|Scolopendra cataracta||Aquatic centipede|
|Scutigera coleoptrata||house centipede|
|Scolopendra gigantea||Peruvian giant yellow-leg centipede|
|Scolopendra heros||giant red-headed centipede|
|Scolopendra morsitans||red-headed centipede|
|Scolopendra polymorpha||giant Sonoran centipede|
|Scolopendra subspinipes||Vietnamese centipede|
Millipedes are a group of arthropods that are characterised by having two pairs of jointed legs on most body segments; they are known scientifically as the class Diplopoda, the name being derived from this feature. Each double-legged segment is a result of two single segments fused together. Most millipedes have very elongated cylindrical or flattened bodies with more than 20 segments, while pill millipedes are shorter and can roll into a ball. Although the name "millipede" derives from the Latin for "thousand feet", no known species has 1,000; the record of 750 legs belongs to Illacme plenipes. There are approximately 12,000 named species classified into 16 orders and around 140 families, making Diplopoda the largest class of myriapods, an arthropod group which also includes centipedes and other multi-legged creatures.
Symphylans, also known as garden centipedes or pseudocentipedes, are soil-dwelling arthropods of the class Symphyla in the subphylum Myriapoda. Symphylans resemble centipedes, but are very small, non-venomous, and only distantly related to both centipedes and millipedes. They can move rapidly through the pores between soil particles, and are typically found from the surface down to a depth of about 50 centimetres (20 in). They consume decaying vegetation, but can do considerable harm in an agricultural setting by consuming seeds, roots, and root hairs in cultivated soil.
Scutigera coleoptrata is a small, typically yellowish-grey centipede with up to 15 pairs of long legs. Originating in the Mediterranean region, the species has spread to other parts of the world, where it can live in human homes, thus gaining the name house centipede. It is an insectivore; it kills and eats other arthropods, such as insects and arachnids.
Solifugae is an order of animals in the class Arachnida known variously as camel spiders, wind scorpions, sun spiders, or solifuges. The order includes more than 1,000 described species in about 153 genera. Despite the common names, they are neither true scorpions nor true spiders. Most species of Solifugae live in dry climates and feed opportunistically on ground-dwelling arthropods and other small animals. The largest species grow to a length of 12–15 cm (5–6 in), including legs. A number of urban legends exaggerate the size and speed of the Solifugae, and their potential danger to humans, which is negligible.
Myriapoda (Ancient Greek myria- + pous is a subphylum of arthropods containing millipedes, centipedes, and others. The group contains over 16,000 species, most of which are terrestrial. Although their name suggests they have myriad legs, myriapods range from having up to 750 legs to having fewer than ten legs.
Scolopendra heros, commonly known as the giant desert centipede, giant Sonoran centipede, Texas redheaded centipede, and giant redheaded centipede, is a species of North American centipede found in the Southwestern United States and Northern Mexico.
Scolopendra gigantea, also known as the Peruvian giant yellow-leg centipede or Amazonian giant centipede, is one of the largest centipedes of the genus Scolopendra with a length up to 30 centimetres (12 in). This species is found in various places in South America and the Caribbean, where it preys on a wide variety of animals, including other sizable arthropods, amphibians, mammals and reptiles.
Lithobius forficatus, most commonly known as the brown centipede or stone centipede, is a common European centipede of the family Lithobiidae, although its distribution is not exclusive to Europe. It is between 18 and 30 mm long and up to 4 mm broad and is a chestnut brown color.
The mouthparts of arthropods have evolved into a number of forms, each adapted to a different style or mode of feeding. Most mouthparts represent modified, paired appendages, which in ancestral forms would have appeared more like legs than mouthparts. In general, arthropods have mouthparts for cutting, chewing, piercing, sucking, shredding, siphoning, and filtering. This article outlines the basic elements of four arthropod groups: insects, myriapods, crustaceans and chelicerates. Insects are used as the model, with the novel mouthparts of the other groups introduced in turn. Insects are not, however, the ancestral form of the other arthropods discussed here.
Scolopendra subspinipes is a species of very large centipede found throughout eastern Asia. One of the most widespread and common species in the genus Scolopendra, this species is also found on virtually all land areas around and within the Indian Ocean, all of tropical and subtropical Asia from Russia to the islands of Malaysia and Indonesia, Australia, South and Central America, the Caribbean islands, and possibly parts of the southern United States. However, how much of this range is natural and how much due to human introduction is unclear. With a wide geographic range and numerous color variations, the species is known by a great many common names including Chinese red-headed centipede, jungle centipede, orange-legged centipede, red-headed centipede and Vietnamese centipede.
Ethmostigmus rubripes, the giant centipede, is the largest Australian centipede. Its size tends to vary in accordance with locality, with the head and body length ranging from 7.5 to over 16 cm, with some individuals exceeding 20 cm. Coloration and patterning varies enormously between specimens from different locations, with shades of yellow and orange being perhaps the most common. Forms from arid climates are often a pale yellow in colour, while those from rainforest habitats typically exhibit dark green or blue coloration. Body proportion also varies with habitat; arid forms are typically very heavily built with proportionally short legs, while their tropical counterparts tend to have longer legs and a lighter build. Ethmostigmus rubripes also has three subspecies, with substantial variation within each.
Scolopendra is a species-rich genus of large tropical centipedes of the family Scolopendridae.
Pachymerium ferrugineum is a species of centipede in the family Geophilidae that can be found in Central Europe, the Iberian Peninsula, Scandinavia, Asian countries such as Japan and Turkey, and on African islands such as the Azores, Canary Islands and Crete. It is also distributed in Alaska and Mexico.
The Cryptopidae are a family of scolopendromorph centipedes. Cryptopids are blind and possess 21 pairs of legs as adults. The genus Cryptops is the numerically largest in the family, comprising over 150 species worldwide.
Himantarium gabrielis is a species of centipede in the family Himantariidae.
Scolopendra hardwickei, the Indian tiger centipede, is a species of centipede in the family Scolopendridae.
Scolopendra cataracta is a species of centipede in the family Scolopendridae. It is the first known amphibious centipede, growing to up to 20 centimetres (7.9 in) in length.
Plutonium zwierleini is one of the largest scolopendromorph centipedes in Europe, and one of the few potentially harmful to humans. Nevertheless, it has been rarely reported, only from the southern part of the Iberian and Italian peninsulas, Sardinia and Sicily.
Scutigerella immaculata, commonly known as the garden symphylan or glasshouse symphylid, is a species of myriapod in the family Scutigerellidae. It may have originated in Europe but now has a cosmopolitan distribution and can be a pest of crops.
In 1902, C.L. Marlatt, an entomologist with the United States Department of Agriculture writes in Circular #48 - The House Centipede: It may often be seen darting across floors with great speed, occasionally stopping suddenly and remaining absolutely motionless, presently to resume its rapid movements, often darting directly at residents, particularly women, evidently with a desire to conceal itself beneath their dresses, creating much consternation.
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