Species Information

Irish brown crab is the most commercially valuable pot-caught species in Ireland.

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Irish brown crab, Cancer pagurus, can occupy a range of habitats from a sandy gravel seabed to rocky reefs. These habitats cover a wide range of depths, from rock pools along the seashore, to a depth of 200 metres.

You will recognise the Irish brown crab by its distinctive "pie-crust" carapace which is reddish-brown on the upper side and pale creamy yellow underneath. It's very large black-tipped claws equip the Irish brown crab with very effective tools for feeding and fighting – if you look closely you will see one claw has developed as a cutting tool while the other is designed as a crusher. When an Irish brown crab loses a claw it can grow a new one, although this may take several years. 

irish brown crab

Irish brown crab use their claws to feed on smaller crustaceans and molluscs and have few predators themselves except for the octopus.

As they have a hard exoskeleton, crabs are only able to grow by moulting, young Irish brown crab moult several times a year while mature Irish brown crab moult once a year or less. They cast their entire outer shell and puff themselves up with water before the new exoskeleton hardens. Full hardening will take 2 to 3 months by which time the brown crab will have increased in size by 20-30%. During hardening, they are the most vulnerable to predators and would be considered lesser quality by fishermen.