Chasmagnathus

Chasmagnathus convexus

"Chasmagnathus convexus" is a common mud-flat crab of the family Varunidae, which is endemic to East Asia. In Japan, this crab is commonly called "hamagani". This crab has two forms that differ in color; one is olive green and the other is purple.
Crab - Chasmagnathus convexus Chasmagnathus convexus,Crab,Taipei,Taiwan

Appearance

Differences in diet are believed to be responsible for the color variation between the two forms. "C. convexus" is large, relative to related crabs, and can reach 4.5 to 5 centimetres wide across its carapace. It is predominantly nocturnal.

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Taxonomy
KingdomAnimalia
DivisionArthropoda
ClassMalacostraca
OrderDecapoda
FamilyVarunidae
GenusChasmagnathus
SpeciesC. convexus
Photographed in
Taiwan