Isokobushi - Isokobushi

A small aquatic animal belonging to the family Osteochondidae, class Crustacea, order Isopoda, phylum Arthropoda. They are often found crowded together under stones on beaches where fresh water flows in. They are around 8 millimeters long, with females being slightly smaller and often being held under the male's chest. Their bodies are oval in shape, with the backs varying from grey-white, yellowish-white, to brown, and sometimes with mottled patterns or scattered black dots. They have no hair, and their bodies are rounded into a sphere. The head and seven thoracic segments are clearly separated, but the abdominal segments are mostly fused, and the abdominal tail segment is large and semicircular. They are endemic to Japan, and are commonly seen all over the country.

[Masamichi Takeda]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

節足動物門甲殻綱等脚(とうきゃく)目コツブムシ科に属する水生小動物。淡水の流入する海浜の石の下などに多数密集していることがある。体長は8ミリメートル内外で、雌はやや小さく、雄の胸下に抱かれていることが多い。体は楕円(だえん)形で、背面は灰白色、黄白色、褐色など個体変化に富み、まだら模様があったり、黒色の小点が散在することもある。体毛はなく、体は球形に丸まる。頭部と7胸節は明瞭(めいりょう)に分離しているが、腹節は大部分が融合し、腹尾節は大きな半円形である。日本特産で、各地にごく普通にみられる。

［武田正倫］

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