Cancer pagurus, commonly known as the edible crab or brown crab, is a species of crab found in the North Sea, North Atlantic Ocean, and perhaps the Mediterranean Sea. It is a robust crab of a reddish-brown colour, having an oval carapace with a characteristic "pie crust" edge and black tips to the claws. A mature adult may have a carapace width up to and weigh up to . C. pagurus is a nocturnal predator, targeting a range of molluscs and crustaceans. It is the subject of the largest crab fishery in Western Europe, centred on the coasts of the British Isles, with more than 60,000 tonnes caught annually. Description The carapace of C. pagurus adults is a reddish-brown colour, while in young specimens it is purple-brown. It occasionally bears white patches, and is shaped along the front edge into nine rounded lobes, resembling a pie crust. Males typically have a carapace long, and females long, although they may reach up to long in exceptional cases. Carapace width is typically , or exceptionally up to . A fold of the carapace extends ventrally to constitute a branchial chamber where the gills lie. The first pereiopod is modified into a strong cheliped (claw-bearing leg); the claw's fingers, the dactylus and propodus, are black at the tips. The other pereiopods are covered with rows of short stiff setae; the dactylus of each is black towards the tip, and ends in a sharp point. From the front, the antennae and antennules are visible. Beside these, the orbits are where the eyes are situated. The mouthparts comprise three pairs of maxillipeds, behind which are a pair of maxillae, a pair of maxillules, and finally the mandibles. Lifecycle Reproduction occurs in winter; the male stands over the female and forms a cage with his legs protecting her while she moults. Internal fertilisation takes place before the hardening of the new carapace, with the aid of two abdominal appendages (gonopods). After mating, the female retreats to a pit on the sea floor to lay her eggs. Between 250,000 and 3,000,000 fertilised eggs are held under the female's abdomen up to eight months until they hatch. The first developmental stage after hatching is a planktonic larva (1 mm) called the zoea that develops into a postlarva (megalopa), and finally a juvenile. The first juvenile stage is characterised by a well-developed abdomen, which in time becomes reduced in