Likewise, it is important to promote studies which help clarify the invasion corridors by defining the pathways, timing and sources of invasion. It is likely that X. secures has been unintentionally introduced in Galician waters via the importation of seeds of oysters from the Mediterranean to shellfish farming areas. In fact, Rola´n (1992) and Rola´n et al. (1985, 1994) recorded a series of non-native molluscan species from the Mediterranean in our sampling area.