The latter name may be because of its habit of basking on weeds out of the water and jumping back into the pool with a plop when it is disturbed. The Blenny has slime-covered skin. It also has sharp comb-like teeth which it uses to crunch barnacles off rocks and to attack dead crabs and pieces of carrion that it cannot swallow whole. The adults are up to 16 cm long and they come inshore to breed during early spring, where the adult male can be found guarding eggs in the large pools. However, it is the young fish that are much more common under rocks and even in holes in the rocks.
Blennies swim with an undulating snake-like motion.
There are two other blennies that can be found between the tides. The larger and fiercer Tompot Blenny Parablennius gattorugine is brownish-orange and has two distinct tentacles on its head. The Montagu's Blenny , Coryphoblennius galerita , is similar, but is covered in pale blue dots, and has a flap of skin on its head. Montagu's Blenny is only found in the south-west of Britain. The gobies are the other family of fishes that are common on the shore.