Oystershell mud crab

Panopeus simpsoni

Family Panopeidae - Mud crabs

Carapace oval anteriorly, widest anteriorly, posterior lateral sides straight, slightly rounded posteriorly, body wider than long; color dark, olive gray to brownish, not solid; claws with characteristic pale mottling; last legs regular, not flattened; 5 spines on anterior lateral edges of carapace, anterior 2 form a broad lobe slightly concave between; claws unequal in size; major chela with enlarge tooth on movable finger; white on palms, white on tips of claws; dark red spot under outer mouth parts (3rd maxillipeds) in all male and some females.
Similar Species
Distinguished from other local mud crabs by having one enlarged tooth on major claw, immovable finger on minor claw not spooned out on inner surface, distinct mottling pattern on claws, and usually (but not always) with red spot under outer mouth part.
Bay, oyster reefs
Maximum Size
5.5 cm (2 1/5 in) carapace width
Other Common Names
Previous Scientific Names
P. herbstii