A mutant crab with two claws on one side has been donated to Newquay’s Blue Reef Aquarium after being hauled up in the pots of a local fisherman.
The bizarre edible crab was caught by Newquay fisherman John Martin, skipper of the fishing boat ‘Tizzard Lee-On’.
As well as a normal pair of fully functional pincers, the 20cm long edible crab also has an additional set growing below his right claw.
Blue Reef’s Jenni Smith said: “It’s relatively unusual to come across crustaceans with extra claws, no one really knows why this sometimes happens, it could be due to environmental factors or be a genetic mutation.
“Crabs, like other crustaceans, are capable of re-growing limbs and claws if they lose or damage them in a fight.
“Perhaps this particular crab’s ability to re-generate lost limbs has got confused and, rather than replacing a missing set of claws, it’s actually ended up growing an extra pair instead.
“Although the extra claws look impressive they can’t actually function so he’s no more dangerous to handle than any other crab,” she added.
The edible crab is the largest of the crab species commonly found around the British Isles. It has characteristic large black tipped claws and a ‘pie-crust’ edge to the shell which make it easily identifiable. Males can weigh up to three kilogrammes.
They are generally nocturnal, scavenging and foraging for food under the cover of darkness and adults are found down to around 100m depth.
Tests have shown that edible crabs’ claws have the crushing strength of over 90 pounds per square inch. An average person’s hand is only capable of squashing to 25 lb per square inch.
They also use them in fights with other crabs and often end losing them although they do re-grow whenever the crab next moults.