Name : Calappa calappa (Linnaeus, 1758)
Length of carapace rather less than half of its extreme width. Edge
of clypeiform expansions entire and smooth. Carapace indistinctly
tuberculated on anterior half but with wavy beaded lines towards the
1758, Syst. Nat. ed. Xii, I. P. 1048
1793, Ent. Syst. Suppl, p. 345
1896, J. Asiatic Soc. Bengal, vol. 65(2), p. 142
1903, Fauna, Geog. Maldive and Laccadive Archipel.p.436
1976, Crabs of japan and Adjacent Seas, p. 129
1997, Resultats des Campagnes MUSORTOM, vol. 18, p.272
Found on the bottoms of rock or broken shells; 10-50 meters deep.
This species ranges widely in tropical Indo-Pacific from Zanzibar,
Mauritius, Maldives, New Caledonia, New Guinea, Japan and Hawaii.
Lakshadweep islands, Andaman & Nicobar islands.
Surface of Carapace nearly smooth anteriorly, marked with transverse
wavy beaded lines posteriorly; its antero-lateral borders crenulated.
Clypeiform expansions very large, their breadth equal to their edge
smoothly moulded posterior border of the carapace. Outer part of the
pterygostomian regions densely hairy. Front slightly projecting beyond
the level of the orbits, bilobed, its breadth at the tip rather less
than the breadth of the orbit. Transverse wing. like expansion near
the distal end of the arm with its edge smooth and entire. Outer surface
of palm with squamiform tubercles and transverse wavy beaded ridges.
Upper margin or crest of palm bluntly dentate.
There are two well known colour morphs occur in these crabs one in
plain coloured and another spotted.