title: Genes predict long distance migration and large body size in a migratory fish, Pacific lamprey.
abstract: Elucidation of genetic mechanisms underpinning migratory behavior could help predict how changes in genetic diversity may affect future spatiotemporal distribution of a migratory species. This ability would benefit conservation of one such declining species, anadromous Pacific lamprey (Entosphenus tridentatus). Nonphilopatric migration of adult Pacific lamprey has homogenized population-level neutral variation but has maintained adaptive variation that differentiates groups based on geography, run-timing and adult body form. To investigate causes for this adaptive divergence, we examined 647 adult lamprey sampled at a fixed location on the Columbia River and radiotracked during their subsequent upstream migration. We tested whether genetic variation [94 neutral and adaptive single nucleotide polymorphisms (SNPs) previously identified from a genomewide association study] was associated with phenotypes of migration distance, migration timing, or morphology. Three adaptive markers were strongly associated with morphology, and one marker also correlated with upstream migration distance and timing. Genes physically linked with these markers plausibly influence differences in body size, which is also consistently associated with migration distance in Pacific lamprey. Pacific lamprey conservation implications include the potential to predict an individual's upstream destination based on its genotype. More broadly, the results suggest a genetic basis for intrapopulation variation in migration distance in migratory species.
authors.affiliation: Columbia River Inter-Tribal Fish Commission Hagerman, ID, USA.
authors.forename: Jon E
authors.initials: JE
authors.lastname: Hess
authors.affiliation: Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho Moscow, ID, USA.
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Caudill
authors.affiliation: Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho Moscow, ID, USA.
authors.forename: Matthew L
authors.initials: ML
authors.lastname: Keefer
authors.affiliation: Columbia River Inter-Tribal Fish Commission Portland, OR, USA.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: McIlraith
authors.affiliation: Fish Ecology Division, Northwest Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration Seattle, WA, USA.
authors.forename: Mary L
authors.initials: ML
authors.lastname: Moser
authors.affiliation: Columbia River Inter-Tribal Fish Commission Hagerman, ID, USA.
authors.forename: Shawn R
authors.initials: SR
authors.lastname: Narum
keywords: anadromous fishes; association study; hydrosystem; migratory species; translocation