Genomic data reveal similar genetic differentiation in aquifer species with different dispersal capabilities and life histories

<p>Little is known about the life histories, genetic structure, and population connectivity of shallow groundwater organisms. We used next-generation sequencing (RAD-seq) to analyze population genomic structure in two aquifer species: <i>Paraperla frontalis</i> (Banks, 1902), a stonefly with groundwater larvae and aerial (winged) adults, and <i>Stygobromus</i> sp., a groundwater-obligate amphipod. We found similar genetic differentiation in each species between floodplains separated by ~70 river km in the Flathead River basin of NW Montana, USA. Given that <i>Stygobromus</i> lacks the aboveground life stage of <i>P. frontalis</i>, our findings suggest that connectivity and magnitude of genetic structure cannot be definitively assumed from life history differences.</p>