Centipede - Centipede

A general term for terrestrial animals belonging to the class Symphyla of the phylum Arthropoda. They are white centipedes with a body length of about 5 mm, and are named after their shape. Their body shape is intermediate between the chelipeds (centipedes) and the insects (totorochilids), and they are classified as a bridging group, called the Symphyla (the same scientific name). They are widely distributed around the world, but are so tiny that they go unnoticed. They have a round or oval head, beaded antennae, and no eyes. Their body has 15 to 17 dorsal plates, and 11 or 12 pairs of walking legs. They have a pair of thick, cone-shaped spinnerets at the end of their tail. They feed on humus, but are also said to feed on young parts of crops, and have been considered a pest of asparagus in America. They are egg-laying, and newly hatched larvae have six antennae and seven pairs of legs, and undergo metamorphosis in which the number of body segments increases with each molt. There are three species in Japan, including the Japanese giant worm, and they are distributed throughout the country.

[Keizaburou Shinohara]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

節足動物門結合綱Symphylaに属する陸生動物の総称。体長5ミリメートル前後のムカデに似た白色の動物で、その形からこの名がある。また体制は、唇脚(しんきゃく)類（ムカデ類）と昆虫の総尾(そうび)類の中間的な形態をもち、分類上その橋渡し的な動物群として結合類（学名の意味も同じ）という。世界中に広く分布するが、微小動物であるために気づかれない。頭は円形か卵形で、数珠(じゅず)状の小節よりなる触角をもち、目はない。胴部は15から17背板があり、歩肢(ほし)は11対または12対。尾端に太い円錐(えんすい)形の出糸突起を1対もっている。腐植質を食べるが、作物の若い部分を食害するともいわれ、アメリカでアスパラガスの害虫とされたことがある。卵生で、孵化(ふか)したばかりの幼虫は触角は6小節、歩肢7対で、脱皮ごとに体節数の増す増節変態をする。日本ではナミコムカデなど3種があり、全国に分布。

［篠原圭三郎］

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