About Paraconcavus pacificus (Pilsbry, 1916)
Paraconcavus pacificus, commonly called the red-striped acorn barnacle, is a species of balanid barnacle. This species is found in subtidal sandy habitats along the outer northeastern Pacific coast, ranging north from Baja California to Monterey Bay. It can reach up to 35 millimeters in diameter, with pink longitudinal stripes covering its white plates. It can be told apart from other large, pink-striped barnacles that live in its range, such as Amphibalanus amphitrite, by the presence of longitudinal striations that cross the growth rings of its plates. Although this barnacle will attach to many different types of hard substrate, it prefers to attach to the shells of other organisms, most often sand dollars.
