Falmouth, Cornwall: The rainbow sea slug is a bizarre and breathtaking animal, and with warming seas it’s gaining a toehold in the south-west
I have never seen a species quite so flamboyant in appearance. A couple of centimetres in length, it was curled beneath the submerged rock like a piece of gaudy costume jewellery.
When the cry went up that one had been found, I had to prevent myself from breaking into a run as I navigated the slippery seaweed-covered boulders to catch my first glimpse of this rarity.
