The western jumping blenny has a body which is slightly compressed and has a steep snout and a naked head, with no scales. The body is coloured greyish to greenish-grey paler underneath. It is marked with dark vertical lines on the head, lines of small dark spots on the dorsal, caudal and pectoral fins and there are irregular blotches along the flanks. It grows to a maximum standard length of. The western jumping blenny is identified from the allopatric but congenericeastern jumping blenny by having a deep incision between the last spine of the first dorsal fin and the first spine of the second dorsalfin, as well as having two spines in the anal fin while the eastern has none.
The western jumping blenny is found in tidal pools and in rocky subtidal and intertidal areas. It occurs where there are algal covered rocks. They occur at depths of. They are frequently encountered out of the water but they can easily return to the water by flicking their tail.