Usually resident in the Caribbean, Mediterranean, and along the western Atlantic, records of the nudibranch Spurilla neapolitana have only recently been edging northwards. Until now, its most northerly sighting was in Brest, France, in August 2025.

Ranging in colour from pink to orange, this sea slug is known for the flattened, long, thick outgrowths on its body (which give rise to its French common name, limace à bigoudis, roughly translated as “hair curler slug”).

Charlotte said:

“I have travelled down to Cornwall to take part in Shoresearch Week annually since 2019. Prisk Cove is one of my favourite shores and, as ever, it was low tide and I was looking through the seaweeds along a reef when this little nudibranch caught my eye.

“It was less than 10mm long and looked similar to a slug I have seen before with its curled cerata, although this one was much more purple.

“It’s quite difficult to see the back of the camera underwater in bright sunlight, so I took a few shots and thought no more of it. It wasn’t until later that evening when I was looking at the photos on a computer screen, that I realised it was in fact something I’d never seen before.

It’s incredibly exciting to see nudibranchs on the shore, and to discover a species new to the UK is a real thrill.

“I’m so grateful for the support and encouragement of everyone involved in Cornwall Wildlife Trust’s Shoresearch Week programme. Five consecutive days of shore surveys is hard work, but it is one of the highlights of my year!”

Within just 24 hours of Charlotte’s find, photos had been sent to marine invertebrate expert Bernard Picton, who confirmed the identification, making Cornwall the host of a brand new UK record.

Matt Slater, Marine Conservation Officer at Cornwall Wildlife Trust, said:

“Charlotte is one of our most dedicated volunteers, and her incredible attention to detail led to this fantastic discovery. You really never know what you may find on a Shoresearch survey! 

“In recent years we have seen a decline in cold water species and increasing numbers of warm water species arriving on our shores. We had an unusually warm summer and oceanic currents would have delivered this animal here as a larvae which settled and has now reached adulthood. 

The fact that this species has been found so far north of its usual range may be another sign that warming seas are influencing the distribution of marine animals.

“This discovery highlights the importance of citizen science and shows just how vital Shoresearch data is in helping us track the changes taking place in our seas in a time when rates of change are accelerating dramatically.”

Shoresearch is a national citizen science project delivered by Cornwall Wildlife Trust to collect data. It has taken place at the same locations and at the same time of year for the last 14 years.

The annual week of surveys takes place across five locations: Helford, Polzeath, St Agnes, Looe, and Fowey. These locations are also home to Cornwall’s first Voluntary Marine Conservation Areas (VMCAs).

This year more than 55 people took part, ranging from seasoned local recorders to first-time rockpool explorers.