Genetic diversity of the NE Atlantic sea urchin Strongylocentrotus droebachiensis unveils chaotic genetic patchiness possibly linked to local selective pressure

• DOI: 10.1007/s00227-015-2801-y
• Publication Date: 2016-01-22T02:42:28Z
• Authors: K. M. Norderhaug; M. B. Anglès d’Au...; C. W. Fagerli; H. Gundersen; H. Christie; K. Dahl; A. Hobæk
• Keywords: Strongylocentrotus droebachiensis; Introgression; Isolation by distance; Population Genetics

We compared the genetic differentiation in green sea urchin Strongylocentrotus droebachiensis from discrete populations on NE Atlantic coast. By using eight recently developed microsatellite markers, structure was between Danish Strait south to Barents Sea north (56-79°N). Urchins are spread by pelagic larvae and may be transported long distances northwards-going ocean currents. Two main superimposed patterns were identified. The first showed a subtle but significant southernmost northernmost of studied could explained an isolation distance model. second pattern included two coastal mid-Norway (65°N), NH NS, as well population continental Norway (71°N) FV. They high degree all other populations. explanation is most likely chaotic patchiness caused introgression another species, S. pallidus, into resulting selective pressure. Ongoing collapse kelp forests recovery observed area NH, NS FV High gene flow spanning more than 22° latitude suggests risk new grazing events occur rapidly future if conditions for urchins favourable. On hand, possibility hybridization association with collapsing used early warning indicator monitoring purposes.