Divers exploring the rocky reefs around Sark this month came across a very rare sea slug. The animal, just two inches long, was found at L’Etac, the islet off the south coast of Little Sark best known for its puffins. Sea slugs, known more correctly as nudibranchs, are often very colourful, unlike their land counterparts, making them popular with divers particularly underwater photographers. Most only have scientific names. This one, Atagema gibba, has previously been recorded from just two locations in the British Isles. It is about two inches long, has a ridge along its back and giraffe-like reticulate patterning. The southerly location of Sark and the warming influence of the Gulf Stream combined with clear water and a huge diversity of underwater life make the island a fascinating location for marine biologists.

Picture by Sue Daly – A new sea slug species for Sark