- The common decapod crustacean, Cancer pagurus, found from Norway to Spain in the North Atlantic. It has a generally mottled brownish red shell with ten legs, two of which have developed into muscular claws, and a tail which is tucked underneath the body. It is up to 20 cm. in diameter. The shell is shed periodically to allow the animal to grow. The edible parts, which must be cooked in salted water (35 g salt per litre), consist of white muscular tissue and a soft brown tissue. The grey feather-like gills (dead man’s fingers), the mouth and the stomach bag and all its green to grey-white contents are discarded. Often served in the shell. It is illegal to sell juvenile crabs (less than 13 cm across) or gravid females in the UK.