Habitat: Exposed rocky reef andcoast, attached to rock surface
Depth: Intertidal
This small bivalve is commonly found in the intertidal area, where it often forms dense aggregations, attached rocky surfaces. It is jet black to blueish black, or occasionally brown in juveniles. Its shell is quite smooth. Although there are other similarly small species of mussels that form dense mats, such as Brachidontes, X. pulex can be distinguished by its smooth shell, which does not have longitudinal ribbing.
