Genetic population structure in Nacella magellanica: Evidence of rapid range expansion throughout the entire species distribution on the Atlantic coast

Nacella magellanica, the most abundant limpet in the Magellanic biogeographic Province of Argentina and Chile, is characterized by a noticeable variability in shell morphology and color patterns. Ecological as well as evolutionary features make this limpet an interesting species for evolutionary and population genetic studies. Here, arbitrary nuclear molecular markers, inter-simple sequence repeat-PCR, are used to analyze the population genetic structure in 14 localities of N. magellanica along 2900 km on the Atlantic coast of the Magellanic Province. We compare the present results, based on nuclear markers, with previous findings of a phylogeographic study that used the mitochondrial COI gene. All the results presented here suggest little genetic structure within N. magellanica, with moderate to high genetic connectivity among populations. The short time elapsed since the expansion of this species plus a possible long larval lifespan and the oceanographic and environmental conditions of the Magellanic Province might explain the lack of genetic structuring and the low levels of genetic differentiation in the species throughout its distribution range along the Argentine coast.