Pleistacantha kannu

Pleistacantha kannu has a pyriform carapace whose dorsal surface is covered with short, conical, broad-based spines and sharp tubercles. Its carapace is about as long postrostrally as it is wide, measuring up to 150 mm (5.9 in) long and up to 138 mm (5.4 in) wide. Its branchial region is strongly inflated, distinguishing it from similar Pleistacantha species such as P. moseleyi, P. pungens, and P. ori. It is the largest spider crab known to inhabit the Indian Ocean. Its carapace ranges from orange to orange-red on the dorsal surface, its chelipeds and walking legs are reddish-brown with white fingers in males and orange and white in females, and its ventral surfaces are dirty white. Its walking legs end in a horn-like tip covered in setae, and they are covered in short tubercles and granules. Its abdomen lacks spines but is covered in numerous blunt and sharp tubercles.