Abstract

The genetic characteristics of introduced species have a significant impact on their ability to establish and spread. The blue mussel (Mytilus galloprovincialis), native to the Mediterranean coast, is a leading invasive species from the intertidal coasts of the world (i.e. America or South Africa). Here, we use mitochondrial DNA sequence data to investigate the genetic diversity and phylogeographic structure of invasive versus native populations. We also evaluated whether genetic diversity in invasive populations could be explained by the genetic characteristics of the native sources from which they derived. The phylogenetic analysis revealed two main lineages indicating a clear separation between the Afro-European and South American populations. On the contrary, we found no evidence of genetic structure in the invasive range in the Southern Pacific. This was probably the result of a recent arrival of M. galloprovincialis to the coasts of America. We also detected the spatial mixture of both lineages in the sampling locations of the Chilean coast, giving rise to high levels of genetic diversity in some areas compared to the population of native mussels. This could lead (potentially) to a better fitness form of these individuals and thus increase the viability of the population and the invasiveness of this species. These results point to the need to better study the populations in which lineages are mixed and, if necessary, to intensify control efforts in them.