In a remarkable discovery made by a volunteer from The Rock Pool Project in Falmouth, England, an extraordinary sight unfolded as rocks were overturned at the end of the day. Vicky Barlow, while lifting a sizeable rock adorned with seaweed, encountered something truly exceptional—a vivid and uncommon spectacle. Seizing the opportunity, she managed to capture a video and several photos of a rare rainbow sea slug, making this encounter only the fourth documented sighting of the creature in the United Kingdom.
The sea slug, scientifically known as Babakina anadoni, belongs to the aeolid nudibranch family. These creatures are renowned for their vibrant hues and distinctive forms. Historically prevalent in warmer oceanic regions, they were primarily observed off the coasts of Portugal, Spain, and France. However, due to rising sea temperatures, their presence has extended to the shores of the U.K., with the initial sighting occurring in August 2022.
Divers and snorkelers have encountered these elusive rainbow sea slugs on a few occasions since the initial sighting, as reported by Barlow and The Rock Pool Project. Nevertheless, it was a groundbreaking moment when a rock pool enthusiast discovered one in the United Kingdom for the first time. Fascinated onlookers observed the creature gracefully navigating its way across the upturned rock before gently returning it to its natural habitat.
Barlow enthusiastically expressed her awe in a blog post recounting the discovery, emphasizing the astonishing diversity of marine life found along Cornwall’s rocky shores. “Today exemplified the incredible wildlife that thrives right at our doorstep,” she wrote.
The sighting of this rare rainbow sea slug not only thrilled the rock pool enthusiasts, but it also drew attention because there were no prior records of the species in the National Biodiversity Network. As such, the captivating video showcased above could potentially be the first documented evidence of its existence in the region. Feel free to watch it and witness the beauty of this colorful and extraordinary creature firsthand.
The warming of sea waters has brought about significant transformations not only for these sea slugs but also for other marine species. Disturbing reports suggest that dolphins, too, are facing severe challenges as a result of global oceanic warming, pushing them perilously close to the brink of survival.