Figure 1.

Perna perna range expansion along the Iberian Peninsula. Presence and absence of P. perna are marked by blue and red dots respectively. White dots represent surveyed sites where no mussel beds were found and yellow dots represent the new range limits of the P. perna distribution. The thick blue line illustrates the previously known P. perna distribution along northern Africa. Surveyed locations are described in Supplementary Table S5, from north to south and west to east. Arrow indicates north. The map was created using the open source software QGIS 2.12.3 (http://www.qgis.org/).