Hermit crab - Hermit crab

A marine animal belonging to the order Decapoda, class Crustacea, family Paguridae. It is common inhabiting the open ocean rocky coasts of Japan and the Korean Peninsula. It is often found near the high tide line, and gathers under stones at low tide. It feeds on more than 20 species of snail shells. It is a small species with a carapace length of about 1 cm, and is a dark gray-green with a distinctive white tip of the walking legs. The right claw is larger. Neither side has hair, but is covered with small sharp granules. Males have three abdominal legs, while females have four. The egg-laying season is from November to March of the following year. It is a different species from P. samuelis found on the Pacific coast of the United States. The closely related long-fingered hermit crab P. dubius is often found in the tidal flats of inland bays around the country. This species is easily distinguished from Paguridae because the phalanges of the walking legs are significantly longer than the pronotum.

[Masamichi Takeda]

Source: Shogakukan Encyclopedia Nipponica About Encyclopedia Nipponica Information | Legend

節足動物門甲殻綱十脚(じっきゃく)目ホンヤドカリ科に属する海産動物。日本全土と朝鮮半島の外洋性岩礁海岸にごく普通に生息する。満潮線付近に多く、干潮のときには石の下などに集まっている。20種以上の巻き貝を利用している。甲長1センチメートルほどの小形種で、濃い灰緑色のじみな色であるが、歩脚の先端部の白色がよく目だつ。はさみ脚(あし)は右側のものが大きい。左右とも毛はないが、とがった小さな顆粒(かりゅう)で覆われている。腹肢は雄では3本、雌では4本。抱卵期は11月から翌年3月。アメリカ太平洋岸のP. samuelisとは別種。各地の内湾の干潟には近縁のユビナガホンヤドカリP. dubiusが多い。この種は歩脚の指節が前節よりも明らかに長いので、ホンヤドカリとは容易に区別がつく。

［武田正倫］

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