Understanding Undulate Rays in Sussex

Sophie Maplesden

Wild Coast Sussex Intern

For National Marine Week we are taking a closer look at the amazing Undulate Ray (Raja undulata), one of the lesser-known species found in Sussex waters.

The Undulate Ray is a globally endangered species according to the IUCN Red List and is a priority protected species in the UK. However, we are lucky here in Sussex to have a healthy population of Undulate Rays. This exotic looking species may not be what you’d expect to find in Sussex waters. While they are found in patchy distributions across the Mediterranean and East Atlantic, the population here in Sussex seems to be thriving, with their numbers increasing over the last decade.

They are found in inshore waters at depths of 20-200 metres where they reside on the seabed, feeding on crustaceans and small fish. Their brown spotted markings help them to camouflage against the seafloor and they often bury themselves beneath the sand and mud. They can grow up to 90cm long and can live for over 20 years.

The threats that Undulate Rays face include overfishing and habitat loss. The reasons for the increased numbers seen in Sussex are not fully known, but one reason may be due to our nine Marine Conservation Zones, in which fishing restricted. These allow the natural restoration of underwater environments which may provide habitats and nutrients for the Undulate Rays.

Despite being called the Undulate Ray, they are actually a species of skate. The difference between rays and skates lies in their reproductive methods: rays produce live offspring, while skates, including the Undulate Ray, lay eggs. Once hatched, these eggcases, also known as mermaid’s purses, often wash up onshore. If you’ve ever seen a mermaid’s purse on the beach in Sussex, it may well have come from an Undulate Ray.

Eggcases are a great way of collecting data about our local Undulate Ray population. The Shark Trust is running The Great Eggcase Hunt, where you can submit pictures and descriptions of any mermaids purses you come across to help them build on their knowledge of sharks, skates and rays in your local area.

Have you seen any mermaid’s purses? Join The Great Eggcase Hunt.

If you want to show your love for the Undulate Ray, check out our Undulate Ray T shirt by David Shrigley for Sussex Wildlife Trust.