Butterfish ©Polly Whyte/Earth in Focus


Scientific name: Pholis gunnellus
The slippery butterfish is a common sight in rockpools all around the UK. Look out for the distinctive black spots on their backs that look a lot like eyes!

Species information


Length: up to 25cm

Conservation status


When to see

January to December


The butterfish is a small eel-like fish found in rockpools and shallow seas all around the UK. They are pretty shy and are normally hidden in crevices or under rocks and seaweed. You might also hear of butterfish being called Gunnels or Rock Gunnels. They feed on anything they can find, including small crustaceans, molluscs and fish eggs. Butterfish lay their eggs on rocky shores, hiding them away from predators in crevices. Unlike in most fish species, both the Mum and the Dad take it in turn to guard their unhatched eggs from hungry predators.

How to identify

Unmistakeable. Pale yellowish-orange to reddish-brown in colour, with bands of darker brown and distinctive white-ringed black spots along the back.


Found on rocky shores all around the UK.

Did you know?

Butterfish get their name from their slimy, buttery skin. If you ever try to catch one, you'll get why!

How people can help

When rockpooling, be careful to leave everything as you found it - replace any seaweed you move out of the way, put back any crabs or fish and ensure not to scrape anything off its rocky home. If you want to learn more about our rockpool life, Wildlife Trusts around the UK run rockpool safaris and offer Shoresearch training - teaching you to survey your local rocky shore. The data collected is then used to protect our coasts and seas through better management or through the designation of Marine Protected Areas. The Wildlife Trusts are working with sea users, scientists, 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 checking out our Action Pages.