The Blenny is widespread and common on rocky shores throughout the length of the British Isles, but its distribution does not extend much further afield, although it is found on all French shores. The Blenny is not found in the Mediterranean Sea. This small fish reaches a length of 165 mm and rests on rocks out of the water when the tide is out.
Juvenile fish can be very common in the pools.
The young fish feed on acorn barnacles. The Common Blenny is also called the Smooth Blenny because it lacks the lappets or fringe on the forehead present in most of this family. The Tompot Blenny lives below the low tide mark and is only occasionally found on the shore. This is the blenny often seen by divers. It is an very aggressive small fish that reaches a length of 30 cm.