‘Beautiful’ colourful sea slug found in Wembury rock pool

Felix said on Instagram the creature was “amazing”.

Dr Paul Naylor, a marine biologist and underwater photographer, said it was “an amazing find”.

Trust marine engagement officer Coral Smith said of the find: “This must be the most brightly coloured, beautiful sea slug (or sea creature for that matter) I have ever seen!”

Only a handful of similar discoveries have ever been made across the UK, with others being concentrated in Cornwall and the Isles of Scilly, the trust said.

However, its appearance was not all good news, as the species was more usually found in the Mediterranean, it added.

Ms Smith said: “The discovery of the rainbow sea slug here in Devon is a strong indicator that our seas are warming due to climate change.

“It really highlights the complexity of how we understand and communicate climate change in the marine environment.”