Red-clawed Crab

Chiromantes haematocheir, commonly known as red-clawed crab, is a species of mudflat crab in the family Sesarmidae. It is endemic to East Asia and quite distinct from the other species placed in the genus Chiromantes. The genus may be restricted to this one species.

 Chiromantes haematocheir has a square carapace with a smooth surface and irregular stripes along the sides. Males have large, smooth chelae with curved claws. The color of these crabs varies throughout their development; juvenile crabs typically have a white or yellow carapace, while adults are usually crimson red.

Mountain crabs: A variety of C. haematocheir can be found in Nagano prefecture, Japan, where elevations often exceed 600 m above sea level, and distances to the ocean can be over 80 km. This indicates that they are freshwater crabs, probably living in forest streams, if they live in water at all.