''Calappa japonica'', also known as the Japanese shame-faced crab, is a marine species of box crab in the

family Family (from la, familia) is a group of people related either by consanguinity (by recognized birth) or affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its members and of society. Idea ...

Calappidae Calappidae is a family of crabs containing 16 genera, of which 7 are only known as fossils: *''Acanthocarpus'' Stimpson, 1871 *'' Calappa'' Weber, 1795 *† '' Calappella'' Rathbun, 1919 *† '' Calappilia'' A. Milne-Edwards, 1873 *'' Calappula ...

. Originally found in the waters around Japan, more recently it has been found in Africa, the Red Sea and Western Australia.

Description

''Calappa japonica'' is a large crab, and has a yellow and red colouration. The length of carapace is approximately .65 times the width, with a tuberculated surface. Seven sharp teeth are located around the margins of each clypeiform expansion.

Distribution and habitat

This species was first discovered in

Tokyo Bay is a bay located in the southern Kantō region of Japan, and spans the coasts of Tokyo, Kanagawa Prefecture, and Chiba Prefecture. Tokyo Bay is connected to the Pacific Ocean by the Uraga Channel. The Tokyo Bay region is both the most populous ...

, Japan. It is now known to occur in regions as far away as Africa and Western Australia, and lives in waters up to deep. as well as being found in the

Red Sea The Red Sea ( ar, البحر الأحمر - بحر القلزم, translit=Modern: al-Baḥr al-ʾAḥmar, Medieval: Baḥr al-Qulzum; or ; Coptic: ⲫⲓⲟⲙ ⲛ̀ϩⲁϩ ''Phiom Enhah'' or ⲫⲓⲟⲙ ⲛ̀ϣⲁⲣⲓ ''Phiom ǹšari''; ...

Behaviour and diet

This crab is a predator, and feeds on invertebrates such as other crabs, as well as oysters and snails. It has a specially adapted right pincer which it uses to break open snail's shells. There is a large accessory tooth located at the base of the hinged part of the claw located opposite a flat plate on the fixed part, and it uses these as a vice. After breaking open the shell, it uses its left pincer, which is sharper and longer than the right one, and better at picking out the soft tissues. When it is disturbed, it folds its

chelae A chela ()also called a claw, nipper, or pinceris a pincer (biology), pincer-like organ at the end of certain limbs of some arthropods. The name comes from Ancient Greek , through New Latin '. The plural form is chelae. Legs bearing a chela are ...

(pincers) in front of its face and retracts its walking legs, forming a compact, well-armoured box-like structure; this defensive stance makes it appear to be embarrassed, and has led to its receiving the name, "shame-faced crab".

References

{{Taxonbar, from=Q5018553 Calappoidea Crustaceans of the Indian Ocean Crustaceans of the Pacific Ocean Crustaceans described in 1892 Taxa named by Arnold Edward Ortmann