A rare multi-coloured sea slug has been seen in UK waters for the first time.
A specimen of Babakina anadoni, which is only 2 centimetres long, was found by a diver off the coast of the Scilly Isles this month.
Allen Murray, a volunteer “sea searcher” for the Cornwall Wildlife Trust, made the discovery while diving near Melledgan, an uninhabited rock island in the archipelago.
He was taking part in the trust’s National Marine Week, and his photograph of the sea slug is the first confirmed record of the species in the UK, the Cornwall Wildlife Trust said.
It has been sighted only a handful of times elsewhere, mainly along the west coast of Spain and further south in the Atlantic, the trust said.
The slug is a member of the aeolid nudibranch family, characterised by bright colours and unusual shapes.
Matt Slater, marine conservation officer at Cornwall Wildlife Trust and co-ordinator of the Seasearch programme, said: “What an incredible find! We were extremely excited to hear about the sighting of this colourful nudibranch — a species that we believe has never been recorded in the UK before.
“It’s one of the prettiest sea slugs I’ve seen and, given it’s less than half the size of your little finger, it’s amazing Allen spotted it at all.
"There’s still so much out there that we don’t know about our marine environment.
“Records like this from our Seasearch divers are vital in helping us understand and better protect our seas.”
Lucy McRobert, communications manager at Isles of Scilly Wildlife Trust, said: “We never cease to be amazed at the wildlife turning up in Scillonian waters.
“From rare and beautiful nudibranchs to violet sea snails to great whales like humpbacks and fins, every time we dive beneath the surface we learn and see something new.”