Perna perna metadata and genotypic data

Studies investigating gene flow in sessile or sedentary marine species typically draw conclusions about larval dispersal by investigating genetic structure of adults. Here, we generated microsatellite data from adults, recruits, settlers and planktonic larvae of the brown mussel, Perna perna, from the south-east coast of South Africa, and identified a consistent mismatch in genetic structure between the adults and all earlier life stages. While adults could be assigned to two major geographical groups (western and eastern), most of the early-stage mussels were strongly affiliated with the eastern group. This result suggests that few of the early-stage individuals present in the western portion of the sampling range will become part of the adult population. Our findings highlight the importance of post-settlement processes as key drivers of population structure and caution against the exclusive use of genetic data generated from adults to assess population connectivity facilitated by the...