Purple striped barnacle

Balanus trigonus

Family Balanidae - barnacles (crustacea)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates, plates usually with purple background and fine white vertical ridges (stripes), walls (radii) in between plates white to purple, smooth; aperture triangular; the small internal plates that close the shell opening (scutum) have distinctive rows of small pits.
Similar Species
There are several purplish stripe barnacles in our area. The most distinguishing feature of this barnacle is the triangular-shaped aperture.
Gulf, bays rarely
Maximum Size
2 cm (3/4 in)
Other Common Names
Previous Scientific Names