title: Geographic extent of introgression inSebastes mentellaand its effect on genetic population structure.
abstract: Genetic population structure is often used to identify management units in exploited species, but the extent of genetic differentiation may be inflated by geographic variation in the level of hybridization between species. We identify the genetic population structure ofSebastes mentellaand investigate possible introgression within the genus by analyzing 13 microsatellites in 2,562 redfish specimens sampled throughout the North Atlantic. The data support an historical divergence between the "shallow" and "deep" groups, beyond the Irminger Sea where they were described previously. A third group,"slope," has an extended distribution on the East Greenland Shelf, in addition to earlier findings on the Icelandic slope. Furthermore,S. mentellafrom the Northeast Arctic and Northwest Atlantic waters are genetically different populations. In both areas, interspecific introgression may influence allele frequency differences among populations. Evidence of introgression was found for almost all the identifiedSebastesgene pools, but to a much lower extent than suggested earlier. Greenland waters appear to be a sympatric zone for many of the genetically independentSebastesgroups. This study illustrates that the identified groups maintain their genetic integrity in this region despite introgression.
authors.affiliation: Tromsø Department Institute of Marine Research Tromsø Norway.
authors.forename: Atal
authors.identifier: 0000-0003-1334-928X
authors.initials: A
authors.lastname: Saha
authors.affiliation: Tromsø Department Institute of Marine Research Tromsø Norway.
authors.forename: Torild
authors.initials: T
authors.lastname: Johansen
authors.affiliation: Greenland Institute of Natural Resources Nuuk Greenland.
authors.forename: Rasmus
authors.initials: R
authors.lastname: Hedeholm
authors.affiliation: DTU Aqua - National Institute of Aquatic Resources Charlottenlund Denmark.
authors.forename: Einar E
authors.initials: EE
authors.lastname: Nielsen
authors.affiliation: Tromsø Department Institute of Marine Research Tromsø Norway.
authors.forename: Jon-Ivar
authors.initials: JI
authors.lastname: Westgaard
authors.affiliation: School of Aquatic and Fishery Sciences University of Washington Seattle WA USA.
authors.forename: Lorenz
authors.initials: L
authors.lastname: Hauser
authors.affiliation: Tromsø Department Institute of Marine Research Tromsø Norway; Hjort Centre for Marine Ecosystem Dynamics Bergen Norway.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Planque
authors.affiliation: School for Marine Science and Technology University of Massachusetts Darmouth Fairhaven MA USA.
authors.forename: Steven X
authors.initials: SX
authors.lastname: Cadrin
authors.affiliation: Greenland Institute of Natural Resources Nuuk Greenland; DTU Aqua - National Institute of Aquatic Resources Charlottenlund Denmark.
authors.forename: Jesper
authors.initials: J
authors.lastname: Boje
keywords: gene flow; hybrid zone; incipient speciation; oceanic; redfish