Ocypode cordimanus (English spelling) Ocypodecordimanus

...This crab belongs to the Ocypodidae family of Crustacea, which lives in holes about 50 cm deep dug in the sand (illustration). The shell reaches a width of 2.5 cm and has an almost square outline. The eye stalk is thick and the cornea is large. One of the chelicerae is larger than the other, and there is a band-like area with a row of thin lines on the inner surface of the palm, which is rubbed against the ridge on the seat to make a sound. The walking legs are strong, with long, curved phalanges that help dig holes, and soft hairs at the base of the second and third walking legs help purify the water they breathe. During the day, the crab is a slightly brownish sand color, but at night the chromatophores shrink and it turns whitish. ...

*Some of the terminology that mentions "Ocypode cordimanus" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…砂浜に深さ50cmほどの穴を掘ってすむ甲殻綱スナガニ科のカニ（イラスト）。甲幅2.5cmに達し，甲の輪郭はほぼ正方形である。眼柄は太く，角膜部が大きい。はさみ脚はいずれか片方が大きく，掌部の内面に細い条線が並んだ帯状部があり，これを座節にある稜でこすって発音する。歩脚はじょうぶで，湾曲した長い指節が穴を掘るのに役だち，また，第2,3歩脚の基部にある軟毛が呼吸水の浄化に役だつ。昼間はやや茶色を帯びた砂色をしているが，夜は色素胞が収縮して白っぽくなる。…

※「Ocypode cordimanus」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報