Semibalanus balanoides, the northern rock barnacle or acorn barnacle, is widespread species of barnacle, found on rocks in the intertidal zone in the boreo-arctic regions of the Atlantic and Pacific ocean.
Southward, A. (2013). Semibalanus balanoides (Linnaeus, 1767). Accessed through: World Register of Marine Species at http://www.marinespecies.org/aphia.php?p=taxdetails&id=106210 on 2016-06-29