Patterns of change in the biogeographic distribution of Atlanto-Mediterranean Aporrhaidae (Gastropoda) from the Neogene to the Present

This paper concerns the geographic distribution of Aporrhais pespelicani (Linné, 1758) and Aporrhais uttingeriana (Risso, 1826) from the Middle Miocene to the Present. As these are the only Aporrhaidae species from the Mediterranean with such an extensive temporal distribution, the changes in their geographic distribution and their relationship with the major environmental changes that affected the Atlanto-Mediterranean area during this period are of interest. Noticeable differences in the geographic distribution of these species are observed. The geographic distribution of A. pespelicani remains approximately constant from the Middle Miocene to the Present, whereas that of A. uttingeriana changed considerably: its northern boundary moved to lower latitudes from the Middle Miocene to the Present. The factors that could have caused these differences are analyzed. The high tolerance of A. pespelicani with respect to temperature and sediment could explain its stable geographic distribution. In contrast, the geographic distribution of A. uttingeriana changed because this species could only live in certain temperature and sediment conditions. Finally, as both species display planktotrophic larval development, they have a high capacity for larval dispersion, which could explain the great longevity of A. uttingeriana, in spite of its reduced ecological tolerance.