A rare sky blue lobster has been rescued by an aquarium after being discovered at a fish market.

The unusual crustacean was spotted by staff at Viviers Fish Market in Portsmouth, Hampshire, who realised its rarity and contacted the Blue Reef aquarium in Southsea.

The colouration is believed to come from a genetic defect that causes the lobster to produce an excessive amount of a particular protein that literally turns the crustacean light blue.

Blue Reef's Lindsay Holloway said: ''It's not the biggest lobster in the world but it's definitely quite unusual.

''The colouring is darker on the claws but the main body of the lobster is a much lighter sky blue and underneath it's virtually white.

''Despite its rarity it's in excellent condition and, once it's been given a thorough health check in quarantine, it will go on public display.''

The European lobster is the largest and strongest of all British crustaceans. It can live for 40 years or more and the largest ever caught was landed in Cornwall in 1931 - weighing in at 9.3kgs and measuring 126cm long from tail to tip of antennae.