Biology/Natural History: This species was introduced from Asia, probably along with oysters. Since they seem to remain in areas near where oysters were planted, their larvae probably have a very short or no pelagic stage. This species is slowly replacing the native snail Cerithidea californica in California bays where they coexist. Both this species and C. californica frequently are infested with abundant cercariae larvae from flukes (Trematodes), and serve as alternate hosts to the flukes which infect seabirds.