title: Genetic versus rearing-environment effects on phenotype: hatchery and natural rearing effects on hatchery- and wild-born coho salmon.
abstract: With the current trends in climate and fisheries, well-designed mitigative strategies for conserving fish stocks may become increasingly necessary. The poor post-release survival of hatchery-reared Pacific salmon indicates that salmon enhancement programs require assessment. The objective of this study was to determine the relative roles that genotype and rearing environment play in the phenotypic expression of young salmon, including their survival, growth, physiology, swimming endurance, predator avoidance and migratory behaviour. Wild- and hatchery-born coho salmon adults (Oncorhynchus kisutch) returning to the Chehalis River in British Columbia, Canada, were crossed to create pure hatchery, pure wild, and hybrid offspring. A proportion of the progeny from each cross was reared in a traditional hatchery environment, whereas the remaining fry were reared naturally in a contained side channel. The resulting phenotypic differences between replicates, between rearing environments, and between cross types were compared. While there were few phenotypic differences noted between genetic groups reared in the same habitat, rearing environment played a significant role in smolt size, survival, swimming endurance, predator avoidance and migratory behaviour. The lack of any observed genetic differences between wild- and hatchery-born salmon may be due to the long-term mixing of these genotypes from hatchery introgression into wild populations, or conversely, due to strong selection in nature--capable of maintaining highly fit genotypes whether or not fish have experienced part of their life history under cultured conditions.
authors.affiliation: Department of Fisheries and Oceans, Centre for Aquaculture and Environmental Research, The University of British Columbia, West Vancouver, British Columbia, Canada.
authors.forename: Cedar M
authors.initials: CM
authors.lastname: Chittenden
authors.forename: Carlo A
authors.initials: CA
authors.lastname: Biagi
authors.forename: Jan Grimsrud
authors.initials: JG
authors.lastname: Davidsen
authors.forename: Anette Grimsrud
authors.initials: AG
authors.lastname: Davidsen
authors.forename: Hidehiro
authors.initials: H
authors.lastname: Kondo
authors.forename: Allison
authors.initials: A
authors.lastname: McKnight
authors.forename: Ole-Petter
authors.initials: OP
authors.lastname: Pedersen
authors.forename: Peter A
authors.initials: PA
authors.lastname: Raven
authors.forename: Audun H
authors.initials: AH
authors.lastname: Rikardsen
authors.forename: J Mark
authors.initials: JM
authors.lastname: Shrimpton
authors.forename: Brett
authors.initials: B
authors.lastname: Zuehlke
authors.forename: R Scott
authors.initials: RS
authors.lastname: McKinley
authors.forename: Robert H
authors.initials: RH
authors.lastname: Devlin
mesh_terms: D025041:Animal Migration; D000818:Animals; D001362:Avoidance Learning; D005260:Female; D005398:Fisheries; D008297:Male; D017684:Oncorhynchus kisutch / Q000235:genetics* / Q000254:growth & development* / Q000502:physiology; D010641:Phenotype; D016019:Survival Analysis; D013550:Swimming
references.citation: Proc Biol Sci. 2004 Aug 7;271 Suppl 5:S350-2
references.pmid: 15504015
references.citation: Genetics. 2004 Apr;166(4):1963-79
references.pmid: 15126412
references.citation: Science. 2007 Oct 5;318(5847):100-3
references.pmid: 17916734
references.citation: Biochimie. 2003 Dec;85(12):1199-205
references.pmid: 14739071
references.citation: Science. 2000 Oct 20;290(5491):516-9
references.pmid: 11039932
references.citation: Evol Appl. 2008 May;1(2):342-55
references.pmid: 25567636
references.citation: Gen Comp Endocrinol. 2008 Oct;159(1):26-37
references.pmid: 18713628
references.citation: Biol Lett. 2009 Oct 23;5(5):621-4
references.pmid: 19515651
references.citation: J Mol Endocrinol. 2006 Oct;37(2):259-82
references.pmid: 17032744