The Corrugated Crab, which is named after the distinctive ridges on its shell, was found in a prawn pot 90 feet underwater by Tim Bailey, a fisherman.

It was discovered in the Fal Estuary in Cornwall, the first time the species has been recorded there for more than 25 years.

The crab has only ever been found in British waters 11 times, nine of which were before 1907.

It is now recovering at the Blue Reef Aquarium in Newquay, Cornwall. The species is native to Britain but is rarely seen because it is nocturnal and a swimming crab, which does not often come to shore.

A spokesman at the aquarium said: "As a crustacean enthusiast it is exciting to finally get to see this particular type of crab in the flesh rather than just in textbooks."

The species, Liocarcinus Corrugatus, grows to a maximum of 6cm, and is reddish-brown in colour, and is nocturnal.

It is also known as the wrinkled swimming crab and it can be aggressive. It has been known to attack divers with its sharp claws.

The spokesman added: "They are native to Britain and to a large part of the globe. They live away from the shores as they are a swimming crab.

"We are hoping to have this one on display. It is actually so feisty that we are keeping it in quarantine. We are trying to recreate the habitat it likes."

by:telegraph