Vicky Barlow was hoping to find a spider crab when she began poking around a rock pool on a beach in Falmouth.
But when she turned over a promising-looking stone, she was astonished to find something much rarer and much more colourful – a rainbow sea slug.
Though the creature – Babakina anadoni – has been spotted off the UK shores by divers and snorkellers, it is believed to be the first time one has been found in a rock pool.
It is not a completely happy story, however, as the appearance of the animal, which is more often found in Spain, Portugal and France, is almost certainly a sign of warming waters caused by the climate emergency.
Barlow, a graphic designer by trade, was volunteering with the Cornwall-based rock pool project when, at the end of a busy day, she decided to take one more look in the pools.
“I decided to hang behind in hopes of finding a spider crab. We often come across these magnificent creatures in the low shore pools. I soon found a large edible crab, a green sea urchin and multiple cushion stars.”
Barlow had a pasty and a cold drink waiting – but took one more look in a larger pool.
“When you have been rock pooling as much as I have been in the last year, you start to get an eye for which rocks are most likely to have something interesting underneath. The last rock I picked up was exactly one of these.
“It was quite a large, heavy rock, covered in various seaweeds, and once lifted something extremely bright and unusual caught my eye.”
She knew at once it was a rainbow sea slug. “The beautiful animal unfurled and revealed itself in full Technicolor,” she said. Barlow took some pictures and video of the creature before gently putting it back where she found it.
Dr Ben Holt, CEO of the Rock Pool Project, said: “As far as we can tell, this is the first time this species has been found by a rock pooler in the UK. It’s a warm-water species but it looks as if it’s arrived here.” Holt said the organisation was seeing “striking changes” around the coast because of the climate emergency.
