Barriers in a sea of elasmobranchs

Background The interplay of animal dispersal and environmental heterogeneity is fundamental for the distribution of biodiversity on earth. In the ocean, the interaction of physical barriers and dispersal has primarily been examined for organisms with planktonic larvae. Animals that lack a planktonic life stage and depend on active dispersal are however likely to produce distinctive patterns. Methods We used available literature on population genetics and phylogeography of elasmobranchs (sharks, rays and skates), to examine how marine barriers and dispersal ecology shape genetic connectivity in animals with active dispersal. We provide a global geographic overview of barriers extracted from the literature and synthesize the geographic and hydrologic factors, spatial and temporal scales to characterize different types of barriers. The three most studied barriers were used to analyse the effect of elasmobranch dispersal potential and barrier type on genetic connectivity. Result...