Cancer irroratus has nine marginal teeth on the front edge of the carapace beside each eye, and reaches a carapace width of 5.25 inches (133 mm). These crabs are similar in color to, and overlap in size with, the Jonah crab, Cancer borealis. The two species can indeed be distinguished by the purplish-brown spots on the carapace of C. irroratus (contrasting with the yellow spots of C. borealis), and by the smooth edges to the teeth on the edge of the carapace (denticulate in C. borealis). Learn more about Atlantic Rock Crab