Also called Gunnel, the Butterfish, Pholis gunnellus is a common, small, inshore fish in the north. It is often found in rock pools and is easily identified by the dorsal fin which extends the whole length of its body and a distinctive row of white-ringed black spots down its back which usually number nine to thirteen. However, I have seen them with only one! The Butterfish attains a length of about 25cms and although eel-like in appearance and its sinuous movements, it is a type blenny. It can often be seen moving in and out of cracks and crannies on inshore reefs searching for worms and small crustaceans on which it feeds.
St. Abbs Marine Reserve, Berwickshire. E. Scotland