Butterfly Crab

Butterfly Crab24″x36″

Butterfly Crab
Cryptolithodes typicus


Friday Harbor Marine Laboratories, University of Washington

San Juan Island, Washington

Archival Pigment Print

“Cryptolithodes” means “hidden stone,” a fitting name for a crab that’s usually hunkered down under its head shield (carapace) in a convincing imitation of a rock. From above, all appendages are hidden from view and the carapace can easily be mistaken for a stone, old clam shell, or patch of algae, depending on its color, which in this species is highly variable. Contributing to the illusion is the fact that the butterfly (aka Darth Vader) crab is one of the slowest moving crabs known, and reacts to danger by clinging to the rock rather than racing away. Being a slow animal, it subsists on slow food: seaweeds, moss animals, and other attached organisms.