Brown crab

Description

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 25 centimetres (10 inches) and weigh up to 3 kilograms (6+1⁄2 pounds). 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. 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 60 mm (2+1⁄4 in) long, and females 98 mm (3+3⁄4 in) long, although they may reach up to 150 mm (6 in) long in exceptional cases. Carapace width is typically 150 mm (6 in), or exceptionally up to 250 mm (9+3⁄4 in).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.