渡辺塾   


ムカデ centipede

ムカデの撮影準備

2008/06/06
寝ていて、夜中の3時に首の後ろを指された。指されたとき、耳元で昆虫を擦り合わせたような、カサという音がしたからムカデだと思う。すぐに調べたが、何処にもいない。逃げ足が速くて、何時も見失ってしまう。毒液が付着したのか、右手前腕部も腫れている。すぐに、風呂場に行って、ぬるま湯を患部にかけ、耳に水が入ってしまうほど何度もかけ、毒を洗い流そうとした。プラスチックのカードで刺された部分から毒を抜いたが、あまり効果がなかった。副腎皮質ホルモンを塗ったが効果がない。これで、三度目で、今までで一番ひどい。ビールを飲んで寝たから寄ってきたのではないかと考えている。二度目の時は咬み後がムカデの歯の間隔で2カ所あった。一度目は確か、天井から落ちてきて、毒液がかかったか、ムカデの足そのものに抗原があるのか、咬み後がないのに腫れた。ネットで対策などを調べてはいたが、今のところ有効な対策が得られないでいる。この地域に移住して5年になるが、3回も被害に遭っている。もうこれ以上なすがままになっていられない。ムカデに対して全面的に攻撃をかける。

2008/06/07
翌日、洗い場へ続く出口で中くらいのムカデがいた。バーナーで焼いた。このムカデが刺したのかもしれない。

今までのムカデ発見の場所
屋根瓦の下
1cmほどの竹を束ねた中にいた。地上から1.5mもどの高さで、冬の終わりか、秋の始まりか、いずれにせよ、寒い時期だったことを覚えている。日向ぼっこで体温を暖めていたのかもしれない。
裏のベランダの大きな石の下、この場所は雨がさほどかからない、適度な湿度が保持されるところで、3回以上同じ場所で発見した。人の力でようやく動かすことのできる石の下に、小さな部屋を作って、じっとしていた。
冷蔵庫の前の、薄暗い土間のくぼみにじっとしていた。
風呂の薪を土間に直接置いていたその下にいた。
こたつの中にいた。
瓦を野積みしていたその中に4,5匹いたと思う。
テラスにある丸太の椅子の下。丸太は直径40cmあり。底面には入り込むことのできる空間があった。
ムカデが土間を走り回っているとき発見したこともあった。
流しの中にいた。洋ちゃんが必死で助けを求めた時だ。

刺された後、ズキズキ痛んだが耐えられない痛さではなかった、ウトウトと朝まで浅い寝りについた。
病院でもらった副腎皮質を塗っていたが、あまり効果が無いみたいなのでムヒアルファEXを塗った。メントールが成分に含まれているので清涼感、すっとして痛みを忘れる。刺されて、3日後の時期に痒みが出てくるがこれにも有効だ。

2008/06/09
夜は落ち着いて寝られなかった。何度も、飛び起きて、布団の下などを探してしまった。
マルチが風で飛ばないようにするための重しとして石を運んでいたまさにその時、大きなムカデを発見した。それがこいつだ。大きな金属製のボールに入れると滑ってはい上がれなくなる。死んだように固まって動かないときがあるが刺激すると活発に動き回る、何らかの作戦なのだろう。





頭部にある2本のひげみたいな触覚を忙しなく動かして、周りの状況を把握しながら行動しているようだ。ピンセットでこの触覚を刺激すると、動きを止め固まった状態から突然、モードが全開になって動き回る。



腹部側から頭部を撮影した。二本の対になった爪。体全体からみても異常なほど発達したこの爪。この爪が両側に大きく開き刺すのだ。見るからに太い外骨格内の筋肉の存在が推測できる。タタラバ蟹のはさみの中と同じだ。ピンセットで広げると、結構強い力があることがわかる。カブトムシを触っていると感じる力と同じだ。この時点で、この爪に刺されて症状が酷くなるのではないと感じた。確かに噛まれた皮膚には2個の点が残るが、この爪は毒液を注入する為の穴が開いていないのだ。たぶん、この巨大な爪には獲物を捕らえるだけの機能しかないのではと思った。推測すると口の近辺に毒液を出す腺があるのではないかと思う、噛まれた皮膚を見ると、対象になった2つの点が数カ所ある、皮膚を無秩序に噛みまくったのだ。口でも皮膚を傷つけたのかもしれない、推測であるが毒液は皮膚表面の比較的浅い場所に刺されるというよりは塗られるのではないかと思う、1回目に刺されたときは天井からムカデが落ちてきて、接触した感じがしただけで、皮膚が腫れた。毒液が飛び散ったのかもしれない、四肢には毒がないという。



若さに欠ける皮膚のスーパーマクロ写真だ。刺されて三日後の写真だ。よく観察するとムカデの両顎による2つの穿刺傷が数カ所みられる。密蜂のように1度だけ刺すのではなく、咬みまくるのだ。右下の黒い点々が前腕の皮膚の毛穴。受傷部の疼痛、腫脹、発赤、掻痒感は勿論あった。右前腕部はランボーのように異様に腫れた。頭に近い後ろ頸部はこれ以上にひどい症状であった。後頭部のリンパ節が数カ所腫れていた。鎖骨近傍まで浮腫った。2回目に刺されたとき、ムカデの両顎による2つの穿刺傷は最後まで残って痒みがなかなか消失しなかった。二カ所が、黄色く化膿したのだ。



ピンセットで顎肢に触ると、素早く何度も咬む。1対の触覚は鞭のようにしなって、周囲を探る。



顎肢のスーパーマクロ写真。見た限りでは穴があるようには見えない。ネットで調べたところ、爪の中に毒腺が開口する、とあったが今度、虫眼鏡で調べてみたい。そばに小さなニンジンがあったので刺すとプスプスくい込む、切れて刺さるような感じだ。この顎肢はかなり堅いが板に刺して引いたら先端がポキッと折れた。
ネットでは”ムカデは顎肢に毒腺を持ち”とあったがどこにあるのだろう。

今回、ムカデを調べてわかったことは、たぶん毒液は皮膚表面にあるから、今度刺されたら丹念に石鹸を使って洗ってからムヒを塗ろうと思う。外国のサイトにはキャッシュカードで皮膚表面をこすって毒液を出すとあったが、あまり効果がなかった。

今後の課題は顎肢をよく観察して毒腺の開口部を確認したい。ガラスコップなどにムカデを入れて毒液の存在を確認したい。

The legs on the first segment behind the head have been modified into hollow tubes, with openings at their sharpened tips, so that they function as fangs. They are attached to venom glands, and are used to kill prey.

顎肢の先端に開口部があって毒液を分泌する腺とつながっているらしい、何時か確認するつもりだ。

Notice that each leg is tipped with a sharp claw. Some sources report that these claws damage unprotected skin, and poison glands are located at the junction of each leg with the body. When the centipede travels over your skin, the claw may penetrate your skin, and poison may be deposited in the cut, producing local inflammation. Of course, I have not tested this hypothesis...

Home Care
Place ice (wrapped in a washcloth or other suitable covering) on the site of the bite for 10 minutes and then off for 10 minutes. Repeat this process. If patient has circulatory problems, decrease the time to prevent possible damage to the skin. A trip to the emergency room will probably not be necessary, but contact poison control just to make sure.

刺された部位を冷やすのは、末梢血管を収縮させて、毒が拡散するのを防ぐからなのだろうか。日本のネットではお湯で洗うなどの記述があったが、血管が拡張して、毒が拡散するのではないか。わからない。

Like all centipedes Scolopendra can inflict a painful bite with a pair of poison claws located directly under the head. These poison claws, once a pair of walking legs, have undergone a drastic change over thousands of years and are now used for capturing and killing their prey instead of walking. So complete is the change and so close is the association with the head, the claws now appear to be mouth parts.

顎肢は足が変化したもので元々足だったのか。顎肢の先端は黒い、他の足の先端も黒い。

Most centipedes can only bite with their poison claws located directly under the head; however, Scolopendra can harm a person with the sharp claws of its many walking legs. Each walking leg is tipped with a sharp claw capable of making tiny cuts in human skin. A poison produced from the attachment point of each leg may be dropped into the wounds resulting in an inflamed and irritated condition. The best rule of thumb is NEVER HANDLE CENTIPEDES.

やっぱり、そうだったんだ。顎肢以外の足は鋭い爪になっていて皮膚を傷つけるのだ、微少な傷ができるのだ。
attachment point 付着点の意味で各足のたぶん付け根だろうな、ここから毒液が落ちるのだ。我ながら、推測が当たっていた。咬まれなくても、触れただけで炎症を起こすのだ。日本のサイトにはこんな情報がなかった。
課題が増えた。無害と言われている、足の鋭さを確認してみよう、毒液が落ちるとの記述があるから注意する必要がある。

2008/06/10
Wash the area with soap and water.
Apply a hot compress to reduce the pain. Or, if you have swelling, use an ice pack or cold compress to help relieve it.

痛みを和らげるために温湿布をして、腫れたら冷湿布か、わからない。

冷湿布は主に炎症、痛みの抑制、治療を狙ったもの。患部が熱を持っているときに使うのが冷湿布。患部が赤く腫れ上がってしまったとき、熱を取って患部の細胞がそれ以上壊されないように、傷みを和らげるようにする対処療法。腫れがあり、熱を持っているので冷やすことが大切です。

温湿布は主に血行の改善を狙ったもの。冷湿布は炎症とかがあるときに熱を取るために使います。 温湿布は血行をよくして血液循環を促し、直りを速めるときに使います。4〜5日たって腫れが退いてきたら血液循環を良くするために温湿布に変えます。

まず第一に石鹸と水で洗うのは良いとして、いずれにせよ傷つけられた表皮から毒が浸透するわけであるから、ムカデ毒を解毒、あるいは溶解するような溶媒で洗うのが最善ではないか、浸透性のある溶媒で、毒を皮下に浸透させないことが重要だと思う。刺された直後は温湿布しない方が良いと思う。理由は毛細血管が拡張して毒が回るからだ。咬まれて、時間が経過した後に、酷く腫れたら冷湿布も良いかもしれない。炎症が起こるとは生体防御の1つであるが過度に腫脹した場合は冷湿布が適当なのではないか。



Centipedes also make interesting photography subjects, but they are so fast-moving that it can be hard to get a picture. Make sure to use a fast film speed in bright light. Another trick: before a photo session, cool down a centipede in a refrigerator for about 15 minutes. The centipede will recover fully in a minute or so after it is removed from the cold, but it will move slowly in the meantime - just enough time for a few good pictures.

冷やしてやったらおとなしくなるのか。

.
Centipede segments possess one pair or two legs that, except for the last pair, arise laterally, are clearly visible along the sides of the body, and function in locomotion. The ultimate or last legs extend backwards well behind the caudal extremity of the body and are not used for locomotion; they may be modified for sensory or defensive functions.

caudal《生物》尾(状)の、尾側の
最尾部の足は感覚器の機能と防衛機能を有している。

Diversity, geologic age, and habit


The Chilopoda is not as diverse and speciose a taxon as the Diplopoda. It comprises only five living orders with around 2,800 described species out of an estimated global fauna of approximately 8,000 species (Adis & Harvey 2000); by contrast, millipedes have over three times as many orders (16) and 10 times as many estimated species (80,000). The Chilopoda also is not as ancient a group, as its fossil history dates back to the late Silurian period of the Paleozoic era, ca. 410 million years ago (Shear 1992). Centipedes occur sporadically north of the Arctic Circle, inhabit all subarctic environments, and are abundant in xeric desert biotopes, where they are one of the most commonly recognized terrestrial invertebrates. They are exclusively carnivores, preying primarily on smaller arthropods, but large-bodied representatives of the order Scolopendromorpha are known to attack and feed on small mammals, snakes, frogs & toads, and birds. Four of the five orders contain agile, fast-moving forms that are adapted for speed; the exception is the Geophilomorpha, whose species move slowly and burrow in the substrate in a manner similar to earthworms, by elongating and contracting their bodies.

“Poison claws”, coloration, and body form


Centipedes are flexible, “opisthogoneate” arthropods (reproductive tracts open at the caudal end of the body) with two anatomical divisions, a head and trunk. Except for the order Scutigeromorpha, they are dorsoventrally (top-to-bottom) flattened, and all chilopods possess “poison claws” (also called “prehensors” or “forcipules”) beneath the head with which they bite prey and potential predators including other centipedes; these structures possess internal glands that secrete venom that is toxic to their prey. Biting and injecting venom is the primary method of defense, but centipedes also employ camouflage, “aposematic” (warning) coloration, and “autotomizing” appendages (dropping those grasped by predators and then outrunning them). A few species also produce defensive secretions, and larger ones appear to have glands in their legs, as merely walking on skin can produce inflamed puncture wounds. Centipedes exhibit two basic body forms and lack the great array of ornamentations that exist in the Diplopoda. Some species are uniformly brown or dark gray in color while others are yellow, orange, red, blue, green, violet, or black; still others possess transverse stripes along the caudal margins of the “tergites” (dorsal plates), and the Indian species, Scolopendra hardwicki, displays alternating orange/red and black tergites.

aposematic 警戒の
autotomize 自分の体の一部を切る
defensive secretion 防御用の分泌物◆昆虫などが防御用に体から噴出したりする


What makes a centipede a centipede? and Modifications for speed


The principal autapomorphy (unique derived character) of the Chilopoda is the “poison claws,” which, though associated with the head, are not mouthparts and are actually appendages of the first segment. The centipedes that are adapted for speed encounter a difficulty, because any long, slender object that moves swiftly forward generates side-to-side undulations that counter this motion (like the swaying of a train), so centipedes have developed anatomical modifications that dampen or reduce the undulations. One of these is “tergite heteronomy,” with alternating short and long plates (well developed in the Lithobiomorpha, poorly developed in the Scolopendromorpha), which shortens the body, thereby reducing the undulations, while maintaining the same number of legs to propel the animal rapidly forward. The other is “tergal fusion,” shown by the Scutigeromorpha, which strengthens the body and makes it more rigid in the places where undulations develop. The coxae (basal articles) of the last legs in geophilomorphs and scolopendromorphs, and the last few legs in lithobiomorphs, possess variable numbers of “coxal pores” that lead to internal glands that are absent from scutigeromorphs. These glands are thought to function as osmoregulatory organs, excreting water under wet conditions and absorbing it in dry environments.


Classification


The class Chilopoda consists of 2 subclasses, 5 orders, and 23 families (see ensuing classification). Nine families occur in the US and Canada, but the number of genera and species is uncertain because the composition of the two most speciose orders, Lithobiomorpha and Geophilomorpha, is unknown as they have never been comprehensively investigated.



The currently accepted classification of the Chilopoda is shown below; subfamilies are provided for the Scolopendromorpha, where Dr. Shelley has more taxonomic experience. Taxa known or thought to occur in North America are marked with asterisks.



Class Chilopoda
Subclass Notostigmophora
Order Scutigeromorpha
Family Pselliodidae
Family Scutigeridae* (Introduced)
Family Scutigerinidae
Subclass Pleurostigmophora
Order Lithobiomorpha
Family Henicopidae*
Family Lithobiidae*
Order Craterostigmomorpha
Family Craterostigmidae
Order Scolopendromorpha
Family Scolopendridae*
Subfamily Scolopendrinae*
Subfamily Otostigminae
Family Scolopocryptopidae*
Subfamily Scolopocryptopinae*
Subfamily Newportiinae
Subfamily Kethopinae*
Family Cryptopidae*
Subfamily Cryptopinae*
Subfamily Plutoniuminae*
Order Geophilomorpha (sensu Foddai, 1998; Foddai and Minelli, 2000)
Suborder Placodesmata
Family Mecistocephalidae
Suborder Adesmata
Superfamily 1
Family Neogeophilidade
Superfamily 2
Family Geophilidae (Geophilus)*
Superfamily 3
Family Geophilidae (other genera)*
Family Linotaeniidae*
Clade 1 (Macronicophilidae + (Aphilodontidae +
Dignathodontidae)
Clade 2 (Eucratonychidae + Eriphantidae + (Gonibregmatidae
+ (Oryidae* [int.])
Clade 3 (Schendylidae* + (Ballophilidae + Himantariidae)

House centipedes, introduced species, and taxonomic characters


In the Scutigeromorpha, the long-legged and swift-moving European species, Scutigera coleoptrata, has been widely introduced into North America and is often encountered in houses in cool, moist places like drains, sinks, bathtubs, and cellars. Additionally, five nominal species have been proposed for forms in Texas and Arizona: S. linceci, homa, dorothea, phana, and buda. Wurmli (1973) placed S. homa, dorothea, and phana in synonymy under S. linceci, but their statuses warrant further study because type specimens do not exist for most of these, particularly S. linceci, described by Wood (1867) from an unspecified site in Texas. If S. linceci is a valid species, a supportive neotype specimen is mandatory, so a thorough scientific investigation of these additional North American scutigeromorphs constitutes a worthy research project. Shelley (2002) surveyed the Scolopendromorpha across the continent and documented an indigenous fauna of eight genera and 21 species. North America is thus the only continent in which this order has been thoroughly studied, and the Scolopendromorpha is one of the few invertebrate orders to have been surveyed across it. Another European centipede, Cryptops hortensis, a small-bodied scolopendromorph, has been widely introduced and is now established in urban environments in the US and Canada, and five additional exogenous species (and one genus) have been encountered occasionally, particularly at ports. The higher taxa (families and orders) are distinguished primarily by the number of segments and legs, the lengths of the appendages, the presence or absence of segmental modifications, the profile and general body form, and the configuration of the head. Determinations of centipede genera and species are more difficult than in millipedes because they lack the all important gonopods and telopods found in chilognath Diplopoda. Many centipede genera and species are superficially similar such that only an experienced taxonomist can distinguish one from another. Taxonomically important characters include the spinulation of the legs, especially the last pair, the setation on the antennae, the position and arrangement of sulci or sutures on the tergites, and the size and configuration of the “coxosternal tooth plates,” which extend anteriorly between the bases of the prehensors.
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The subclass Notostigmophora contains one order, Scutigeromorpha


The subclass Notostigmophora contains only one order, Scutigeromorpha, which contains three families, 16 genera, and around 80 described species out of an estimated global fauna of 100-150 species (Adis & Harvey 2000). Scutigeromorphs are relatively short-bodied centipedes in which the “spiracles” (openings to the trachea or respiratory system) are located middorsally. Adults possess 15 pairs of very long legs that become progressively longer caudally, and the antennae are very long and whip-like, consisting of two basal articles and a long flagellum with hundreds of very short articles. The head is hemispherical or “dome shaped” and possesses two compound eyes that differ from those of insects; the trunk is not dorsoventrally flattened, and while adults have 15 “sterna” (ventral plates), there are only seven large terga because of “tergal fusion.” Scutigeromorphs demonstrate “anamorphic” development (they hatch from the egg with less than the full adult complement of legs and segments, and add legs and segments, and grow larger, at subsequent molts until they reach this number) and hatch with only four segments and leg pairs. Scutigeromorphs are extremely fast, agile, and delicate centipedes that are difficult to catch and collect intact; the legs are readily autotomized, and few museum specimens possess all 15 pairs.
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The subclass Pleurostigmophora contains the remaining orders


The remaining four orders, containing the vast majority of species, belong to the subclass Pleurostigmophora, which comprises dorsoventrally flattened centipedes in which the spiracles are located laterally and the appendages are not prolonged; eyes, when they exist, are simple ocelli on both sides of the head. Two orders, Lithobiomorpha and Craterostigmomorpha, demonstrate “anamorphic” development, while the Scolopendromorpha and Geophilomorpha are “epimorphic” (hatchlings emerge from the egg with the full adult complement of legs and segments and grow larger at subsequent molts). In the “epimorphic” orders, the eggs and early stadia are “brooded” by females, which curl or hump their bodies over the egg masses, whereas eggs are laid singly and not brooded in the Lithobiomorpha. According to Lewis (1981), brooding occurs in the anamorphic Craterostigmomorpha, but little is known about life history and development in this order.
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Lithobiomorpha, strong tergite heteronomy (different sized tergites)


The Lithobiomorpha comprise short-bodied forms with 15 pairs of legs and segments in adults, and 7 (rarely 6 or 8) in hatchlings. They exhibit strong tergite heteronomy, as tergites 1, 3, 5, 7, 8, 10, 12, and 14 are much longer than those of the other segments. Lithobiomorphs typically possess ocelli, but a few, mostly cavernicolous species, have lost them. The order occurs globally and comprises two families that are distinguished by the presence of setae alone on the legs (Henicopidae) or spines/spurs plus setae (Lithobiidae). There are 95 genera, and ca. 1,500 species have been described from an estimated global fauna of >2,000 species (Adis & Harvey 2000).
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Craterostigmomorpha, one family, one genus, and one species


The Craterostigmomorpha is the most geographically restricted and least-diverse order. It occurs only in Tasmania (not Australia proper) and New Zealand, and was thought to be restricted to the South Island of the latter until Shelley (2002) cited it from the North Island based on a discovery by G. Edgecombe. The order comprises only one family, one genus, and one described species (Craterostigmus tasmanianus); there is at most only one other species, currently undescribed, as some specialists believe the form in New Zealand is specifically distinct. Craterostigmomorphs have 15 pairs of legs and sterna, but there appear to be 21 tergites (plus a terminal structure) because tergites 3, 5, 7, 8, 10, and 12 are subdivided. There is one pair of ocelli; the head capsule is longer than wide; and the “poison claws” extend well in front of the latter and are clearly visible in dorsal view (from above). The terminal structure is bizarre, as it consists of two valves that are fused dorsally but meet in a longitudinal slit ventrally; its function is unknown.
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Scolopendromorpha, the body form that most people envision when centipedes are mentioned


The order Scolopendromorpha contains the most readily recognized chilopods and is the body form that most people envision when centipedes are mentioned. Opinions differ as to the number of component families and their respective names, but the consensus seems to be three families ? Scolopendridae, Scolopocryptopidae, and Cryptopidae ? based in part on the presence (Scolopendridae) or absence (Scolopocryptopidae and Cryptopidae) of two pairs of ocelli on each side of the cephalic plate and the number of segments (21 in the Scolopendridae [except for Scolopendropsis, which has 23] and the Cryptopidae, and 23 in the Scolopocryptopidae). The last family is sometimes cited as “Newportiidae,” and both names were established by Pocock (1896), Scolopocryptopidae coming on p. 28 immediately before Newportiidae, on p. 29. Neither name has priority based on Pocock’s treatment, but Shelley (2002, pp. 2-3) noted that according to Article 24.2.2 of the present Code and the action of Attems (1930), as first reviser, Scolopocryptopidae has priority, and Newportiinae is thus one of three subfamilies; for these reasons, Scolopocryptopinae cannot be a subfamily under Newportiidae.


Like lithobiomorphs, scolopendromorphs exhibit “tergite heteronomy, ” but here it is poorly developed; segments 2, 4, 6, 9, 11, 13, 15, 17, and 19 are shorter than the others, but this is noticeable primarily on the anterior segments and barely perceptible on the caudal ones. The “pleurites” (lateral plates) of the terminal segment are fused with the inflated coxae of the last legs to form “coxopleurae” that extend caudally into a process that is usually armed with spines and spurs. The last legs are larger than the preceding pairs and appear to function in part as prehensile appendages to hold or pinch prey; in the Scolopendridae the prefemora (the second leg articles) possess variable numbers of ventral spines and spurs. Also in this family there is a dorsal distomedial “prefemoral process” that is armed with a variable number of spurs, and there is a spine in this position in two species of the cryptopid genus Theatops. The number of spines/spurs and their arrangements are taxonomically important at the generic and specific levels as are the presence/absence/number of spines/spurs on the walking legs.


According to Adis & Harvey (2000), the Scolopendromorpha presently contains 33 genera and around 600 species with an estimated global fauna of around 800 species. The Scolopendromorpha includes the world’s largest centipedes; Shelley and Kiser (2000) documented a specimen of Scolopendra gigantea from Venezuela that is nearly 275 mm (11 in.) long, and there are undocumented reports on the web of specimens of around 400 mm (16 in.) on Curacao. Some scolopendromorphs are anatomically and behaviorally intriguing, for example species of the African genus Alipes, which have large, leaf-like terminal legs that vibrate rapidly from side to side when disturbed to produce a rustling or fluttering sound. Another is Arrhabdotus octosulcatus, a slow-moving, apparently arboreal species in the rain forests of Borneo with very short legs, whose tergites possess seven strong longitudinal ridges (one of the few ornamented centipedes) that impart exceptional rigidity to the body (Lewis 1981a, b). Arrhabdotus octosulcatus obviously occupies a different ecological niche from other scolopendromorphs and hence differs in basic anatomical traits; on first glance, it more closely resembles a millipede of the order Polydesmida than a scolopendromorph (Lewis 1981b). Scolopendra subspinipes, native to southeast Asia but introduced into many areas of the world, particularly oceanic islands, can swim, a beneficial usage of undulations that is advantageous for rain forest species that are likely to be immersed during monsoonal floods. The top of the head and tergites, except for the last three, protrude from the water, and the centipede swims in a serpentine manner with the legs held against the sides of the body (Lewis 1980, 1981a).
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Geophilomorpha, burrowers, diversity of habitat, diversity of form


The final centipede order, Geophilomorpha, is unique in several ways. It is the only one whose species are not adapted for speed and instead burrow slowly in the substrate; it is the only order in which species reach the magic figure of 100 legs (the number in this order, always an odd number of pairs, ranging from 54 [27 pairs] to 382 [191 pairs]); and it is the only order with appreciable diversity, as there are currently 14 component families, 180 genera, and ca. 1,100 described species out of an estimated global fauna of around 4,000 species. Eyes are always absent, and the head is usually lenticular in shape, though it can be elongated and rectangular, as in the Mecistocephalidae. The last pair of legs typically lies along the longitudinal body axis; and the inflated coxae bear variable numbers of pores. Geophilomorphs vary greatly in size, from around 5 to 195 mm ( 0.2 to 7.8 in.) in length; some are thin and fragile while others are broad and ribbon-like. They occur natively on all the inhabited continents and some species have been introduced onto oceanic islands. They range from sea level to high elevations in the Andes and Himalaya Mountains, and several species have adapted to living in the littoral zones of sea-shores, a difficult environment to adapt to because of the high salinities.
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Centipedes and humans


As with millipedes, we close this general section by addressing the impact of chilopods on humans. All centipedes possess “poison claws” and can inject venom, but most are too small and weak to penetrate human skin. However, large and even moderate-size scolopendromorphs and scutigeromorphs, with their powerful “prehensors,” can inflict painful bites that may generate intense pain, swelling, discoloration, numbness, and necrosis, and necessitate a visit to a doctor. However, unlike scorpions and spiders, there are no really dangerous, deadly centipedes, and the only suspected instance of a human fatality is of a 7 year old child in the Philippines who was bitten on the head by a Scolopendra and the poison quickly entered the brain. Dr. Shelley was once bitten on a finger by a specimen of Scolopocryptops sexspinosus that was slightly over an inch long, and the digit swelled up and throbbed for about an hour, thus being similar to a wasp sting. In the southeastern US, Hemiscolopendra marginata, which can grow to 75 or so mm (3 in.) in length, frequently enters buildings, and persons accidentally encountering it can be bitten. During World War II, Scolopendra subspinipes was a scourge to American soldiers fighting in the Pacific. It is a wandering species, and large individuals roamed freely around military installations, falling into foxholes and entering latrine shelters and tents, where they would crawl into blankets on beds. Many soldiers were bitten and experienced instant, fiery pain; medical staff were frequently called to treat centipede bites, and an ingenious medic conceived of injecting localized dental anesthetics in the vicinities of bites, which afforded quick relief (Remington 1950). Thus, while there are no dangerous, deadly centipedes, the bite of large ones can cause severe pain and discomfort, to the point that persons living in tropical areas should be suitably cautious. Collectors should always pick up even moderate-sized species with forceps, never the hands, and because of the flexibility of their bodies, specimens should always be grasped behind the head so as to be able to control the biting end of the body. If they are grasped near mid-length or caudally, the animals can bend their bodies 180 degrees and still bite one’s hand or fingers.
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In the female, the last pair of legs is more than twice the length of its body.

The legs on the first segment behind the head have been modified into hollow tubes, with openings at their sharpened tips, so that they function as fangs. They are attached to venom glands, and are used to kill prey.


The centipede's bite is considered about as serious as a bee sting, but the risk of secondary infection is also important to consider. Because centipedes are opportunistic feeders, and will scavenge dead animals and excrement that it encounters during foraging activities, it may be an efficient reservoir and vector for pathogens that such food sources may contain. Some authorities discount this possibility, however. Texas A&M scientists recommend that centipedes never be handled by humans, to avoid the risk of being bitten.


Once the centipede positions its fangs for an attack, it is able by virtue of these muscles to sink them deeply into the body of its prey, even through a tough cuticle.

cuticle
【名】
《生化学》クチクラ、外皮
The last segment on the centipede's body has two legs that stick out in the form of a "V". These are "prehensile" legs, which means they are capable of wrapping around, grasping, and seizing objects. These legs are used to seize smaller organisms that the centipede wants to feed on.


When a larger animal attempts to attack, it often mistakes the last segment for the head, thinking the prehensile legs are antennae. When this happens the centipede is able to arch around and give its antagonist a good fight, and usually manages to escape.