The waters off the Isles of Scilly have been the scene of the discovery, for the first time in British waters, of an incredibly rare sea slug. Babakina anadoni is possibly the most colorful sea slug in the world.
It was spotted by Allen Murray, a volunteer with CWT’s Seasearch Diving project, which aims to record marine habitats and species found in UK waters and use the information to identify sites of specific conservation interest. The sighting is even more remarkable considering that, despite its striking colors, it is barely the size of a little finger.
His photograph of the sea slug is the first confirmed record of the species in the UK, according to the Cornwall Wildlife Trust. It has been seen only a handful of times elsewhere, mainly along the west coast of Spain and further south into the Atlantic, the trust said. Babakina anadoni feeds on the stinging cells of hydroids, small creatures related to corals and jellyfish. Remarkably, Babakina anadoni ‘s intestine extends into each of its finger-like anatomical structures known as cerata, and this is where it processes food.
Like a sea slug, B. anadon i sits among the nudibranchs, which are a famous and quirky group. Among them are species that look like grapes, sheep, bananas, and even one that can decapitate its own head to grow a new body from scratch . As well as being spectacularly colourful, our rainbow sea slug has an unusual sex life. Being hermaphrodites , both parties to a mating pair are equipped with both sets of reproductive organs.
Sea slugs fight with their penises to decide who is the “dominant male”, and the winner is the first to penetrate the body wall of the other sea slug.
unexpected find
The Trust’s Seasearch project recruits volunteer divers to record marine habitats and species around the Cornish coast.
The species was first described in 1979 and placed in the genus Rioselleolis, but was later assigned to the genus Babakina.
His finding is surprising since it is quite north of where the species lives. Previously it had only been recorded along the west coast of Spain and further south in the Atlantic, but never before in the UK.
“We never cease to be amazed at the wildlife that shows up in Scillonian waters,” said Lucy McRobert, Communications Manager for the Isles of Scilly Wildlife Trust. “From rare and beautiful nudibranchs to purple sea snails and large whales like humpbacks and fins, every time we dive below the surface we learn and see something new!”
