Striped barnacle

Balanus amphitrite amphitrite

Family Balanidae - barnacles (crustacea)

Shell conical, made of 6 triangular plates (parietes) fused together with walls (radii) between plates; walls (radii) narrow with oblique outer edge; plates are whitish with irregularly spaced vertical dark, reddish purple or brown stripes; no horizontal striations; base plate is calcareous, usually stays on hard substrate when barnacle is removed; side plates (parietes) somewhat smooth but may have shallow vertical ridges; aperture is basically diamond-shaped but flat or rounded at 1 end; internal plate tergum with spur (rounded extension) about as wide as long.
Similar Species
There are several purplish stripe barnacles in our area. Similar to the reticulated striped barnacle, B. reticulatus, but the reticulated striped barnacle has slight horizontal grooves giving it a reticulated pattern. It also has a longer tergal spur (longer than wide). The purple striped barnacle, B. trigonus is distinguished by its triangular opening.
Gulf and bay, attaches to hard substrates
Maximum Size
2 cm (3/4 in)
Other Common Names
Previous Scientific Names