Environmental correlates of population differentiation in Atlantic herring.

摘要: The marine environment is characterized by few physical barriers, and pelagic fishes commonly show high migratory potential low, albeit in some cases statistically significant, levels of genetic divergence neutral marker analyses. However, it not clear whether low differentiation reflect spatially separated populations experiencing gene flow or shallow population histories coupled with limited random drift large, demo- graphically isolated undergoing independent evolutionary processes. Using information for nine micro- satellite loci a total 1951 fish, we analyzed among Atlantic herring from eleven spawning locations distributed along longitudinal gradient the North Sea to Western Baltic. Overall differ- entiation was ( u5 0.008) but significant. area dramatic shift hydrography highly saline temperature stable brackish Baltic Sea, where temperatures annual variation. We used two different methods, novel computational geometric approach partial Mantel correlation analysis detailed environmental that patterns reproductive isolation covaried salinity differences locations, their geograph- ical distance. can be maintained fish exhibiting substantial mixing during larval adult life stages. Analyses incorporating genetic, spatial, parameters indicated isolating mechanisms are associated specific conditions on locations.