Colonies of the phlebobranch ascidian Perophora japonica were found in August 2003 in Humboldt Bay, northern California, growing on a submerged settling panel. This species has a unique terminal budding in addition to the usual subterminal stolonial budding: bright yellow stellate plaques form at the tips of many stolons. The plaques break off, float away and reattach, subsequently forming new stolons and new colonies. The presence of these plaques, and the larger size of the zooids, distinguish it from the native Perophora annectens. This is the first North American record for this species.