Balanus crenatus (common barnacle)

Found all over the mussel beds.

This barnacle is similar to Balanus glandula both of which carry the common name acorn barnacle. This barnacle has also been called common barnacle and has been given that name here to avoid confusion of two acorn barnacles. It has a similar structure of overlapping plates. Balanus crenatus is normally wider in diameter than it is tall. The shell of Balanus crenatus is noted for smoothness. The specimen below is on the back of a kelp crab.