Barriers in a sea of elasmobranchs: From <i>fishing</i> for populations to testing hypotheses in population genetics

Background The interplay of animal dispersal and environmental heterogeneity is fundamental for the distribution biodiversity on earth. In ocean, interaction physical barriers has primarily been examined organisms with planktonic larvae. Animals that lack a life stage depend active are however likely to produce distinctive patterns. Methods We used available literature population genetics phylogeography elasmobranchs (sharks, rays skates) examine how marine ecology shape genetic connectivity in animals dispersal. provide global geographical overview extracted from synthesize hydrological factors, spatial temporal scales characterize different types barriers. three most studied were analyse effect elasmobranch potential barrier type connectivity. Results characterized nine broad barriers, common being related ocean bathymetry. maximum depth occurrence, body size habitat each species as proxies potential, important predictors varying depending type. Environmental tolerance reproductive behaviour may also play crucial role However, we find studies commonly appropriate study designs based priori hypotheses test while accounting behaviour. Main conclusions Our synthesis highlights relative contribution shaping populations. new perspective interact rearrange variation illustrate methodological sources can bias detection solutions future research field.