Sea Potato

Sea Potato

Scientific name: Echinocardium cordatum
The Sea Potato is a type of sea urchin that lives buried in the sand. Their empty tests (shells) are often found washed up on the beach.

Species information


Diameter: 6-9cm Average Lifespan: 10-20 years

Conservation status


When to see

January to December


The Sea Potato is a medium-sized sea urchin that lives buried in sandy and muddy seabeds all around UK coasts. It lives in a burrow between 8 and 15cm deep and can be found buried on beaches and in the seabed out to depths of 200m. It feeds on detritus collected from within its burrow using its tube feet. When alive, it is covered in fine, beige spines that give it a furry appearance. Often, the empty test (shell) is found washed ashore and is white and brittle.

How to identify

The familiar white 'test' (shell) of the dead animal is often washed up on the shore. It is recognisable by the heart shape, dull whiteish colour and thin, brittle shell. The animal itself is covered in dense fur-like spines.


Found on sandy and muddy shores all round our coasts.

Did you know?

The test of a Sea Potato is distinctively heart shaped - giving them their other common name of Heart Urchin. A slightly nicer name than Sea Potato!

How people can help

Sea Urchins and starfish provide a vital link in the food chain for many of our rarer species. Our seas and coastline are in need of protection if we are to keep our marine wildlife healthy. The Wildlife Trusts are working with fishermen, researchers, politicians and local people towards a vision of 'Living Seas', where marine wildlife thrives. Do your bit for our Living Seas by supporting your local Wildlife Trust or check out our Action pages.