rock crab the common name of Cancer irroratus, a W. Atlantic (Labrador to Florida) relation of the better-known European crab (see crab, common) and dungeness crab. The yellowish carapace, dotted with brown or purplish spots, may measure a little over 10 cm (4") across.
The rock crab in turn has a close relation, C. borealis, the Jonah crab. This is slightly larger, and has bigger claws. It has a similar range but is only found in a limited number of localities.
© the Estate of Alan Davidson 1999, 2006, 2014 © in the Editor’s contribution to the second and third editions, Oxford University Press 2006, 2014.