Picton said he believed the animal to be an undescribed Lomanotus species, a genus of sea slug.<\/p>\n
Being undescribed means it had never been identified, named or documented before, the Marine Biological Association added.<\/p>\n
The association has appealed to divers, rockpoolers, sailors and fishers to record anything similar they spot and submit photographs to its data archive centre called DASSH, external<\/a>.<\/p>\n A spokesperson said the recordings helped scientists to build a clearer picture of how coasts and seas were changing as waters warmed, including sightings of “unusual visitors and shifting species ranges”.<\/p>\n “The discovery is another reminder that the marine life around Britain is ever-changing,” the association said.<\/p>\n In 2025, young rockpoolers who joined the monthly Rock Pool Project Bioblitz, external<\/a>, found a rare depilatory sea hare<\/a> on Mount Batten beach in Plymouth.<\/p>\n Follow BBC Devon on X, external<\/a>, Facebook, external<\/a> and Instagram, external<\/a>. Send your story ideas to spotlight@bbc.co.uk, external<\/a>.<\/p>\n