Fisherman Mickaël Gault made the catch in the Bay of Saint-Brieuc, Côtes d’Armor.
“Another fisherman had seen it off Saint-Quay-Portrieux, two or three years ago,” said Mr Gault. “But he did not want to talk about it.”
Despite Brittany being famous for its seafood dishes, the lobster has escaped being cooked and has been transferred to the Océanopolis marine museum in Brest.
European lobsters have a slightly blueish tint but nothing like the vivid iridescence of this one. Specialists at the Lobster Institute at Maine University, US, say only one lobster in two million is this colour, which is caused by a genetic anomaly resulting in the production of a protein.
The Breton lobster’s age is unknown but lobsters can live for around 40 years in captivity.