Pachygrapsus crassipes belongs to the Crustacean order Decapoda, infraorder Brachyura, or “short-tailed” crabs.  Known as the Lined Shore Crab, this species is a true crab (it contains 10 full pairs of appendages), and the upper surface is transversely striated with green stripes along the black/purple carapace.  This species has been the guinea pig for a variety of marine biology experiments due to its abundance along the west coast of the North American intertidal, ranging from Oregon to Baja California, Mexico.  This species is native to the eastern Pacific, though by 1890s it made its way across the ocean to Asia (South Korea, Japan), presumably as zoea larvae that were caught in the water ballasts of ships moving across the Pacific.

 

P. crassipes possess the unique Crustacean qualities such as:

• hormonally controlled molting cycles

• limb detachment via specialized muscles and regeneration

• complex organs for sight and sound production