1
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Folio DM, Gil J, Caudron A, Labonne J. Genotype-by-environment interactions drive the maintenance of genetic variation in a Salmo trutta L. hybrid zone. Evol Appl 2021; 14:2698-2711. [PMID: 34815748 PMCID: PMC8591331 DOI: 10.1111/eva.13307] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2021] [Revised: 08/18/2021] [Accepted: 09/15/2021] [Indexed: 11/28/2022] Open
Abstract
Allopatric gene pools can evolve in different directions through adaptive and nonadaptive processes and are therefore a source of intraspecific diversity. The connection of these previously isolated gene pools through human intervention can lead to intraspecific diversity loss, through extirpation of native populations or hybridization. However, the mechanisms leading to these situations are not always explicitly documented and are thus rarely used to manage intraspecific diversity. In particular, genotype-by-environment (GxE) interactions can drive postzygotic reproductive isolation mechanisms that may result in a mosaic of diversity patterns, depending on the local environment. We test this hypothesis using a salmonid species (Salmo trutta) in the Mediterranean (MED) area, where intensive stocking from non-native Atlantic (ATL) origins has led to various outcomes of hybridization with the native MED lineage, going from MED resilience to total extirpation via full hybridization. We investigate patterns of offspring survival at egg stage in natural environments, based on parental genotypes in interaction with river temperature, to detect potential GxE interactions. Our results show a strong influence of maternal GxE interaction on embryonic survival, mediated by maternal effect through egg size, and a weak influence of paternal GxE interaction. In particular, when egg size is large and temperature is cold, the survival rate of offspring originating from MED females is three times higher than that of ATL females' offspring. Because river temperatures show contrast at small scale, this cold adaptation for MED females' offspring constitutes a potent postzygotic mechanism to explain small-scale spatial heterogeneity in diversity observed in MED areas where ATL fish have been stocked. It also indicates that management efforts could be specifically targeted at the environments that actively favor native intraspecific diversity through eco-evolutionary processes such as postzygotic selection.
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Affiliation(s)
- Dorinda Marie Folio
- Université de Pau et des Pays de l’AdourUMR INRAE‐UPPAEcobiopSaint‐Pée‐sur‐NivelleFrance
- SCIMABIO InterfaceThonon‐les‐BainsFrance
| | - Jordi Gil
- UMR CARRTELINRAEUSMBThonon‐les‐BainsFrance
- Conservatoire des Espaces Naturels Rhône‐AlpesVogüeFrance
| | | | - Jacques Labonne
- Université de Pau et des Pays de l’AdourUMR INRAE‐UPPAEcobiopSaint‐Pée‐sur‐NivelleFrance
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2
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Perry WB, Kaufmann J, Solberg MF, Brodie C, Coral Medina AM, Pillay K, Egerton A, Harvey A, Phillips KP, Coughlan J, Egan F, Grealis R, Hutton S, Leseur F, Ryan S, Poole R, Rogan G, Ryder E, Schaal P, Waters C, Wynne R, Taylor M, Prodöhl P, Creer S, Llewellyn M, McGinnity P, Carvalho G, Glover KA. Domestication-induced reduction in eye size revealed in multiple common garden experiments: The case of Atlantic salmon ( Salmo salar L.). Evol Appl 2021; 14:2319-2332. [PMID: 34603501 PMCID: PMC8477603 DOI: 10.1111/eva.13297] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2021] [Accepted: 08/24/2021] [Indexed: 11/28/2022] Open
Abstract
Domestication leads to changes in traits that are under directional selection in breeding programmes, though unintentional changes in nonproduction traits can also arise. In offspring of escaping fish and any hybrid progeny, such unintentionally altered traits may reduce fitness in the wild. Atlantic salmon breeding programmes were established in the early 1970s, resulting in genetic changes in multiple traits. However, the impact of domestication on eye size has not been studied. We measured body size corrected eye size in 4000 salmon from six common garden experiments conducted under artificial and natural conditions, in freshwater and saltwater environments, in two countries. Within these common gardens, offspring of domesticated and wild parents were crossed to produce 11 strains, with varying genetic backgrounds (wild, domesticated, F1 hybrids, F2 hybrids and backcrosses). Size-adjusted eye size was influenced by both genetic and environmental factors. Domesticated fish reared under artificial conditions had smaller adjusted eye size when compared to wild fish reared under identical conditions, in both the freshwater and marine environments, and in both Irish and Norwegian experiments. However, in parr that had been introduced into a river environment shortly after hatching and sampled at the end of their first summer, differences in adjusted eye size observed among genetic groups were of a reduced magnitude and were nonsignificant in 2-year-old sea migrating smolts sampled in the river immediately prior to sea entry. Collectively, our findings could suggest that where natural selection is present, individuals with reduced eye size are maladapted and consequently have reduced fitness, building on our understanding of the mechanisms that underlie a well-documented reduction in the fitness of the progeny of domesticated salmon, including hybrid progeny, in the wild.
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Affiliation(s)
- William Bernard Perry
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
- Water Research InstituteSchool of BiosciencesCardiff UniversityCardiffUK
- Population Genetics Research GroupInstitute of Marine ResearchBergenNorway
| | - Joshka Kaufmann
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | | | - Christopher Brodie
- Ecosystems and Environment Research CentreSchool of Environment and Life SciencesUniversity of SalfordSalfordUK
| | | | - Kirthana Pillay
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
| | - Anna Egerton
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
| | - Alison Harvey
- Population Genetics Research GroupInstitute of Marine ResearchBergenNorway
| | - Karl P. Phillips
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Jamie Coughlan
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Fintan Egan
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Ronan Grealis
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Steve Hutton
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Floriane Leseur
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Sarah Ryan
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | | | - Ger Rogan
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Elizabeth Ryder
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Patrick Schaal
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
- Institute of BiodiversityAnimal Health & Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Catherine Waters
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Robert Wynne
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
| | - Martin Taylor
- School of Biological SciencesUniversity of East AngliaNorwichUK
| | - Paulo Prodöhl
- Institute for Global Food SecuritySchool of Biological SciencesMedical Biology CentreQueen’s UniversityBelfastUK
| | - Simon Creer
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
| | - Martin Llewellyn
- Institute of BiodiversityAnimal Health & Comparative MedicineUniversity of GlasgowGlasgowUK
| | - Philip McGinnity
- School of Biological, Earth and Environmental SciencesUniversity College CorkCorkIreland
- Marine InstituteFurnace, NewportCo. MayoIreland
| | - Gary Carvalho
- Molecular Ecology and Fisheries Genetics LaboratorySchool of Biological ScienceBangor UniversityBangor, GwyneddUK
| | - Kevin Alan Glover
- Population Genetics Research GroupInstitute of Marine ResearchBergenNorway
- Institute of BiologyUniversity of BergenBergenNorway
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3
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Wacker S, Aronsen T, Karlsson S, Ugedal O, Diserud OH, Ulvan EM, Hindar K, Næsje TF. Selection against individuals from genetic introgression of escaped farmed salmon in a natural population of Atlantic salmon. Evol Appl 2021; 14:1450-1460. [PMID: 34025778 PMCID: PMC8127704 DOI: 10.1111/eva.13213] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 01/14/2021] [Accepted: 02/26/2021] [Indexed: 11/27/2022] Open
Abstract
The viability of wild Atlantic salmon populations is threatened by genetic introgression from escaped farmed salmon. Farmed Atlantic salmon are genetically improved for important commercial traits and a life in captivity but are poorly adapted to the natural environment. The rate of gene flow from escaped farmed to wild salmon depends on their spawning success and on offspring survival at various life stages. We here investigate relative survival of introgressed juvenile Atlantic salmon (parr) in a river in northern Norway. The studied population has experienced genetic introgression from farmed salmon for about four generations (20 years). We followed two cohorts of parr from the year of hatching (0+) to the age of 2 years (2+). Farmed genetic introgression was quantified at the individual level and on a continuous scale using diagnostic SNPs. Population-level genetic introgression decreased from 0+ to 2+ by 64% (2011 cohort) and 37% (2013 cohort). This change was driven by a 70% (2011 cohort) and 49% (2013 cohort) lower survival from age 0+ to 2+ in introgressed parr compared to parr of wild origin. Our observations show that there is natural selection against genetic introgression with a potential cost of lower productivity.
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Affiliation(s)
| | - Tonje Aronsen
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Sten Karlsson
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Ola Ugedal
- Norwegian Institute for Nature ResearchTrondheimNorway
| | | | - Eva M. Ulvan
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Kjetil Hindar
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Tor F. Næsje
- Norwegian Institute for Nature ResearchTrondheimNorway
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4
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Nilsson E, Sadler-Riggleman I, Beck D, Skinner MK. Differential DNA methylation in somatic and sperm cells of hatchery vs wild (natural-origin) steelhead trout populations. ENVIRONMENTAL EPIGENETICS 2021; 7:dvab002. [PMID: 34040807 PMCID: PMC8132314 DOI: 10.1093/eep/dvab002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/03/2020] [Revised: 03/09/2021] [Accepted: 03/01/2021] [Indexed: 05/06/2023]
Abstract
Environmental factors such as nutrition, stress, and toxicants can influence epigenetic programming and phenotypes of a wide variety of species from plants to humans. The current study was designed to investigate the impacts of hatchery spawning and rearing on steelhead trout (Oncorhynchus mykiss) vs the wild fish on a molecular level. Additionally, epigenetic differences between feeding practices that allow slow growth (2 years) and fast growth (1 year) hatchery trout were investigated. The sperm and red blood cells (RBC) from adult male slow growth/maturation hatchery steelhead, fast growth/maturation hatchery steelhead, and wild (natural-origin) steelhead were collected for DNA preparation to investigate potential alterations in differential DNA methylation regions (DMRs) and genetic mutations, involving copy number variations (CNVs). The sperm and RBC DNA both had a large number of DMRs when comparing the hatchery vs wild steelhead trout populations. The DMRs were cell type specific with negligible overlap. Slow growth/maturation compared to fast growth/maturation steelhead also had a larger number of DMRs in the RBC samples. A number of the DMRs had associated genes that were correlated to various biological processes and pathologies. Observations demonstrate a major epigenetic programming difference between the hatchery and wild natural-origin fish populations, but negligible genetic differences. Therefore, hatchery conditions and growth/maturation rate can alter the epigenetic developmental programming of the steelhead trout. Interestingly, epigenetic alterations in the sperm allow for potential epigenetic transgenerational inheritance of phenotypic variation to future generations. The impacts of hatchery exposures are not only important to consider on the fish exposed, but also on future generations and evolutionary trajectory of fish in the river populations.
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Affiliation(s)
- Eric Nilsson
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Ingrid Sadler-Riggleman
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Daniel Beck
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Michael K Skinner
- Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
- Correspondence address. Center for Reproductive Biology, School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA. Tel: +1-509-335-1524; E-mail:
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5
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Rahman MM, Siddique A, Rahman MA, Rahman SM, Asaduzzaman M, Khanom M, Khatun MM, Hasan MM. The interactive effects of paternal size and offspring feeding strategy on offspring fitness of an Indian major carp
Labeo rohita
(Hamilton, 1822). AQUACULTURE RESEARCH 2020; 51:2421-2431. [DOI: 10.1111/are.14586] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Accepted: 02/18/2020] [Indexed: 09/27/2023]
Affiliation(s)
- Md. Moshiur Rahman
- Tokyo University of Marine Science and Technology Tokyo Japan
- Fisheries & Marine Resource Technology Discipline Khulna University Khulna Bangladesh
| | - Asif Siddique
- Fisheries & Marine Resource Technology Discipline Khulna University Khulna Bangladesh
| | - Md. Ashikur Rahman
- Fisheries & Marine Resource Technology Discipline Khulna University Khulna Bangladesh
| | - Sheikh Mustafizur Rahman
- Fisheries & Marine Resource Technology Discipline Khulna University Khulna Bangladesh
- Fish Resources Research Center King Faisal University Hofuf Al‐Ahsa Kingdom of Saudi Arabia
| | - Md. Asaduzzaman
- Department of Marine Bioresource Science Chittagong Veterinary and Animal Sciences University Chittagong Bangladesh
| | - Momotaz Khanom
- Fisheries & Marine Resource Technology Discipline Khulna University Khulna Bangladesh
| | - Mst. Muslima Khatun
- Fisheries & Marine Resource Technology Discipline Khulna University Khulna Bangladesh
| | - Md. Mehedi Hasan
- Fisheries & Marine Resource Technology Discipline Khulna University Khulna Bangladesh
- Sydney School of Veterinary Science Faculty of Science The University of Sydney Camden NSW Australia
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6
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Besnier F, Solberg MF, Harvey AC, Carvalho GR, Bekkevold D, Taylor MI, Creer S, Nielsen EE, Skaala Ø, Ayllon F, Dahle G, Glover KA. Epistatic regulation of growth in Atlantic salmon revealed: a QTL study performed on the domesticated-wild interface. BMC Genet 2020; 21:13. [PMID: 32033538 PMCID: PMC7006396 DOI: 10.1186/s12863-020-0816-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2019] [Accepted: 01/28/2020] [Indexed: 12/23/2022] Open
Abstract
Background Quantitative traits are typically considered to be under additive genetic control. Although there are indications that non-additive factors have the potential to contribute to trait variation, experimental demonstration remains scarce. Here, we investigated the genetic basis of growth in Atlantic salmon by exploiting the high level of genetic diversity and trait expression among domesticated, hybrid and wild populations. Results After rearing fish in common-garden experiments under aquaculture conditions, we performed a variance component analysis in four mapping populations totaling ~ 7000 individuals from six wild, two domesticated and three F1 wild/domesticated hybrid strains. Across the four independent datasets, genome-wide significant quantitative trait loci (QTLs) associated with weight and length were detected on a total of 18 chromosomes, reflecting the polygenic nature of growth. Significant QTLs correlated with both length and weight were detected on chromosomes 2, 6 and 9 in multiple datasets. Significantly, epistatic QTLs were detected in all datasets. Discussion The observed interactions demonstrated that the phenotypic effect of inheriting an allele deviated between half-sib families. Gene-by-gene interactions were also suggested, where the combined effect of two loci resulted in a genetic effect upon phenotypic variance, while no genetic effect was detected when the two loci were considered separately. To our knowledge, this is the first documentation of epistasis in a quantitative trait in Atlantic salmon. These novel results are of relevance for breeding programs, and for predicting the evolutionary consequences of domestication-introgression in wild populations.
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Affiliation(s)
- Francois Besnier
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.
| | - Monica F Solberg
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Alison C Harvey
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Deiniol Road, Bangor, LL57 2UW, UK
| | - Gary R Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Deiniol Road, Bangor, LL57 2UW, UK
| | - Dorte Bekkevold
- Section for Marine Living Resources, National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Martin I Taylor
- School of Biological Sciences, University of East Anglia, Norwich, NR4 7TJ, UK
| | - Simon Creer
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Bangor University, Deiniol Road, Bangor, LL57 2UW, UK
| | - Einar E Nielsen
- Section for Marine Living Resources, National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Øystein Skaala
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Fernando Ayllon
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Geir Dahle
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen, Norway
| | - Kevin A Glover
- Population Genetics Research group, Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen, Norway
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7
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O'Sullivan RJ, Aykanat T, Johnston SE, Kane A, Poole R, Rogan G, Prodöhl PA, Primmer CR, McGinnity P, Reed TE. Evolutionary stasis of a heritable morphological trait in a wild fish population despite apparent directional selection. Ecol Evol 2019; 9:7096-7111. [PMID: 31312431 PMCID: PMC6617767 DOI: 10.1002/ece3.5274] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/03/2019] [Accepted: 05/04/2019] [Indexed: 12/14/2022] Open
Abstract
Comparing observed versus theoretically expected evolutionary responses is important for our understanding of the evolutionary process, and for assessing how species may cope with anthropogenic change. Here, we document directional selection for larger female size in Atlantic salmon, using pedigree-derived estimates of lifetime reproductive success as a fitness measure. We show the trait is heritable and, thus, capable of responding to selection. The Breeder's Equation, which predicts microevolution as the product of phenotypic selection and heritability, predicted evolution of larger size. This was at odds, however, with the observed lack of either phenotypic or genetic temporal trends in body size, a so-called "paradox of stasis." To investigate this paradox, we estimated the additive genetic covariance between trait and fitness, which provides a prediction of evolutionary change according to Robertson's secondary theorem of selection (STS) that is unbiased by missing variables. The STS prediction was consistent with the observed stasis. Decomposition of phenotypic selection gradients into genetic and environmental components revealed a potential upward bias, implying unmeasured factors that covary with trait and fitness. These results showcase the power of pedigreed, wild population studies-which have largely been limited to birds and mammals-to study evolutionary processes on contemporary timescales.
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Affiliation(s)
- Ronan James O'Sullivan
- School of Biological, Earth & Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Tutku Aykanat
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | - Susan E. Johnston
- Institute of Evolutionary Biology, School of Biological SciencesUniversity of EdinburghEdinburghUK
| | - Adam Kane
- School of Biology and Environmental Science and Earth InstituteUniversity College DublinDublinIreland
| | | | - Ger Rogan
- Marine Institute, FurnaceNewportMayoIreland
| | - Paulo A. Prodöhl
- Institute for Global Food Security, School of Biological Sciences, Medical Biology CentreQueen's University BelfastBelfastUK
| | - Craig R. Primmer
- Organismal and Evolutionary Biology Research Program, Faculty of Biological and Environmental SciencesUniversity of HelsinkiHelsinkiFinland
| | - Philip McGinnity
- School of Biological, Earth & Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
| | - Thomas Eric Reed
- School of Biological, Earth & Environmental SciencesUniversity College CorkCorkIreland
- Environmental Research InstituteUniversity College CorkCorkIreland
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8
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Skaala Ø, Besnier F, Borgstrøm R, Barlaup B, Sørvik AG, Normann E, Østebø BI, Hansen MM, Glover KA. An extensive common-garden study with domesticated and wild Atlantic salmon in the wild reveals impact on smolt production and shifts in fitness traits. Evol Appl 2019; 12:1001-1016. [PMID: 31080511 PMCID: PMC6503829 DOI: 10.1111/eva.12777] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2018] [Revised: 01/18/2019] [Accepted: 01/19/2019] [Indexed: 01/15/2023] Open
Abstract
Interactions between domesticated escapees and wild conspecifics represent a threat to the genetic integrity and fitness of native populations. For Atlantic salmon, the recurrent presence of large numbers of domesticated escapees in the wild makes it necessary to better understand their impacts on native populations. We planted 254,400 eggs from 75 families of domesticated, F1-hybrid, and wild salmon in a river containing up- and downstream traps. Additionally, 41,630 hatchery smolts of the same pedigrees were released into the river. Over 8 years, 6,669 out-migrating smolts and 356 returning adults were recaptured and identified to their families of origin with DNA. In comparison with wild salmon, domesticated fish had substantially lower egg to smolt survival (1.8% vs. 3.8% across cohorts), they migrated earlier in the year (11.8 days earlier across years), but they only displayed marginally larger smolt sizes and marginally lower smolt ages. Upon return to freshwater, domesticated salmon were substantially larger at age than wild salmon (2.4 vs. 2.0, 4.8 vs. 3.2, and 8.5 vs. 5.6 kg across sexes for 1, 2, and 3 sea-winter fish) and displayed substantially lower released smolt to adult survival (0.41% vs. 0.94% across releases). Overall, egg-to-returning adult survival ratios were 1:0.76:0.30 and 1:0.44:0.21 for wild:F1-hybrid:domesticated salmon, respectively, using two different types of data. This study represents the most updated and extensive analysis of domesticated, hybrid, and wild salmon in the wild and provides the first documentation of a clear genetic difference in the timing of smolt migration-an adaptive trait presumed to be linked with optimal timing of entry to seawater. We conclude that spawning and hybridization of domesticated escapees can lead to (i) reduced wild smolt output and therefore wild adult abundance, through resource competition in freshwater, (ii) reduced total adult abundance due to freshwater competition and reduced marine survival of domesticated salmon, and (iii) maladaptive changes in phenotypic traits.
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Affiliation(s)
| | | | - Reidar Borgstrøm
- Faculty of Environmental Sciences and Natural Resource ManagementÅsNorway
| | | | | | | | | | - Michael Møller Hansen
- Institute of Marine ResearchNordnes, BergenNorway
- Department of BioscienceAarhus UniversityAarhus CDenmark
| | - Kevin Alan Glover
- Institute of Marine ResearchNordnes, BergenNorway
- Department of Biological SciencesUniversity of BergenBergenNorway
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9
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Lemopoulos A, Prokkola JM, Uusi‐Heikkilä S, Vasemägi A, Huusko A, Hyvärinen P, Koljonen M, Koskiniemi J, Vainikka A. Comparing RADseq and microsatellites for estimating genetic diversity and relatedness - Implications for brown trout conservation. Ecol Evol 2019; 9:2106-2120. [PMID: 30847096 PMCID: PMC6392366 DOI: 10.1002/ece3.4905] [Citation(s) in RCA: 77] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 11/30/2018] [Accepted: 12/21/2018] [Indexed: 12/24/2022] Open
Abstract
The conservation and management of endangered species requires information on their genetic diversity, relatedness and population structure. The main genetic markers applied for these questions are microsatellites and single nucleotide polymorphisms (SNPs), the latter of which remain the more resource demanding approach in most cases. Here, we compare the performance of two approaches, SNPs obtained by restriction-site-associated DNA sequencing (RADseq) and 16 DNA microsatellite loci, for estimating genetic diversity, relatedness and genetic differentiation of three, small, geographically close wild brown trout (Salmo trutta) populations and a regionally used hatchery strain. The genetic differentiation, quantified as F ST, was similar when measured using 16 microsatellites and 4,876 SNPs. Based on both marker types, each brown trout population represented a distinct gene pool with a low level of interbreeding. Analysis of SNPs identified half- and full-siblings with a higher probability than the analysis based on microsatellites, and SNPs outperformed microsatellites in estimating individual-level multilocus heterozygosity. Overall, the results indicated that moderately polymorphic microsatellites and SNPs from RADseq agreed on estimates of population genetic structure in moderately diverged, small populations, but RADseq outperformed microsatellites for applications that required individual-level genotype information, such as quantifying relatedness and individual-level heterozygosity. The results can be applied to other small populations with low or moderate levels of genetic diversity.
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Affiliation(s)
- Alexandre Lemopoulos
- Department of Environmental and Biological SciencesUniversity of Eastern FinlandJoensuuFinland
- Department of BiologyUniversity of TurkuTurkuFinland
| | - Jenni M. Prokkola
- Department of Environmental and Biological SciencesUniversity of Eastern FinlandJoensuuFinland
- Institute of Integrative BiologyUniversity of LiverpoolLiverpoolUK
| | - Silva Uusi‐Heikkilä
- Department of BiologyUniversity of TurkuTurkuFinland
- Department of Biological and Environmental ScienceUniversity of JyväskyläJyväskyläFinland
| | - Anti Vasemägi
- Department of BiologyUniversity of TurkuTurkuFinland
- Department of Aquatic Resources, Institute of Freshwater ResearchSwedish University of Agricultural SciencesDrottningholmSweden
- Estonian University of Life SciencesInstitute of Veterinary Medicine and Animal SciencesTartuEstonia
| | - Ari Huusko
- Natural Resources Institute Finland (Luke), Kainuu Fisheries Research StationPaltamoFinland
| | - Pekka Hyvärinen
- Natural Resources Institute Finland (Luke), Kainuu Fisheries Research StationPaltamoFinland
| | | | - Jarmo Koskiniemi
- Department of Agricultural SciencesUniversity of HelsinkiHelsinkiFinland
| | - Anssi Vainikka
- Department of Environmental and Biological SciencesUniversity of Eastern FinlandJoensuuFinland
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10
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Robertsen G, Reid D, Einum S, Aronsen T, Fleming IA, Sundt‐Hansen LE, Karlsson S, Kvingedal E, Ugedal O, Hindar K. Can variation in standard metabolic rate explain context-dependent performance of farmed Atlantic salmon offspring? Ecol Evol 2019; 9:212-222. [PMID: 30680108 PMCID: PMC6342125 DOI: 10.1002/ece3.4716] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 10/18/2018] [Accepted: 10/20/2018] [Indexed: 01/13/2023] Open
Abstract
Escaped farmed Atlantic salmon interbreed with wild Atlantic salmon, leaving offspring that often have lower success in nature than pure wild salmon. On top of this, presence of farmed salmon descendants can impair production of wild-type recruits. We hypothesize that both these effects connect with farmed salmon having acquired higher standard metabolic rates (SMR, the energetic cost of self-maintenance) during domestication. Fitness-related advantages of phenotypic traits associated with both high SMR and farmed salmon (e.g., social dominance) depend on environmental conditions, such as food availability. We hypothesize that farmed offspring have an advantage at high food availability due to, for example, dominance behavior but suffer increased risks of starvation when food is scarce because this behavior is energy-demanding. To test these hypotheses, we first compare embryo SMR of pure farmed, farmed-wild hybrids and pure wild offspring. Next, we test early-life performance (in terms of survival and growth) of hybrids relative to that of their wild half-siblings, as well as their competitive abilities, in semi-natural conditions of high and low food availability. Finally, we test how SMR affects early-life performance at high and low food availability. We find inconclusive support for the hypothesis that domestication has induced increased SMR. Further, wild and hybrid juveniles had similar survival and growth in the semi-natural streams. Yet, the presence of hybrids led to decreased survival of their wild half-siblings. Contrary to our hypothesis about context-dependency, these effects were not modified by food availability. However, wild juveniles with high SMR had decreased survival when food was scarce, but there was no such effect at high food availability. This study provides further proof that farmed salmon introgression may compromise the viability of wild salmon populations. We cannot, however, conclude that this is connected to alterations in the metabolic phenotype of farmed salmon.
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Affiliation(s)
| | - Donald Reid
- School of Life Sciences, College of Medical, Veterinary and Life SciencesUniversity of GlasgowGlasgowUK
| | - Sigurd Einum
- Centre for Biodiversity Dynamics, Department of BiologyNorwegian University of Science and TechnologyTrondheimNorway
| | - Tonje Aronsen
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Ian A. Fleming
- Department of Ocean SciencesMemorial University of NewfoundlandSt John’sNewfoundlandCanada
| | | | - Sten Karlsson
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Eli Kvingedal
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Ola Ugedal
- Norwegian Institute for Nature ResearchTrondheimNorway
| | - Kjetil Hindar
- Norwegian Institute for Nature ResearchTrondheimNorway
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11
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Mayer I. The Role of Reproductive Sciences in the Preservation and Breeding of Commercial and Threatened Teleost Fishes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1200:187-224. [PMID: 31471798 DOI: 10.1007/978-3-030-23633-5_7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/02/2022]
Abstract
The teleost fishes are the largest and most diverse vertebrate group, accounting for nearly half of all known vertebrate species. Teleost fish exhibit greater species diversity than any other group of vertebrates and this is reflected in the unique variety of different reproductive strategies displayed by fish. Fish have always been an important resource for humans worldwide, especially as food. While wild capture fisheries have historically been the main source of fish, the farming of fish (aquaculture) is increasingly becoming the more dominant source of food fish, and is predicted to account for 60% of total global fish production by 2030.Fishes are increasingly threatened by a wide range of anthropogenic impacts, including loss of habitat, pollution, invasive species and over-exploitation. In addition, climate change, especially the consequences of global warming, can impact fish at all levels of biological organization from the individual to the population level, influencing both physiological and ecological processes in a variety of direct and indirect ways. As such, there is an urgent need to protect and conserve the huge genetic diversity offered by this diverse vertebrate group, not just as a source of genes for contemporary breeding and for protection against the consequences of climate change and disease, but also as part of our national heritage. While the cryopreservation of reproductive cells is a means of achieving these objectives, currently only fish sperm can be successfully frozen. Due to their large size, large yolk compartment, low membrane permeability and high chilling sensitivity, successful and reproducible protocols for the cryopreservation of fish oocytes and embryos still remains elusive. However, significant advances have been made in the cryopreservation of primordial germ cells as an alternative means of conserving both paternal and maternal genomes. Although more research needs to be carried out on how these cells can be optimally applied to emerging reproductive technologies, including transplantation techniques and surrogate broodstock technologies, the successful cryopreservation of fish germ cells, and the establishment of genetic resource banks, offers the possibility of both conserving and restoring threatened species. Further, current and future conservation efforts need to consider the impact of climate change in both in situ conservation and reintroduction efforts.In conclusion, it is anticipated that the successful cryopreservation of fish germplasm will result in a range of economic, ecological and societal benefits. In partnership with emerging assisted reproductive technologies, the successful cryopreservation of fish germplasm will lead to more efficient reproduction in aquaculture, assist selective breeding programmes, and be of crucial importance to future species conservation actions.
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Affiliation(s)
- Ian Mayer
- Norwegian University of Life Sciences, Faculty of Veterinary Medicine, Oslo, Norway.
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12
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Harvey AC, Skilbrei OT, Besnier F, Solberg MF, Sørvik AGE, Glover KA. Implications for introgression: has selection for fast growth altered the size threshold for precocious male maturation in domesticated Atlantic salmon? BMC Evol Biol 2018; 18:188. [PMID: 30558529 PMCID: PMC6298023 DOI: 10.1186/s12862-018-1294-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2017] [Accepted: 11/16/2018] [Indexed: 01/31/2023] Open
Abstract
BACKGROUND Mature male parr (MMP) represent an important alternative life-history strategy in Atlantic salmon populations. Previous studies indicate that the maturation size threshold for male parr varies among wild populations and is influenced by individual growth, environmental conditions, and genetics. More than ten generations of breeding have resulted in domesticated salmon displaying many genetic differences to wild salmon, including greatly increased growth rates. This may have resulted in domesticated fish with the potential to outgrow the size threshold for early maturation, or evolution of the size threshold of the trait itself. To investigate this, we performed a common-garden experiment under farming conditions using 4680 salmon from 39 families representing four wild, two wild-domesticated hybrid, and two domesticated strains. RESULTS Domesticated salmon outgrew wild salmon 2-5-fold, and hybrids displayed intermediate growth. Overall, the numbers of MMP varied greatly among families and strains: averaging 4-12% in domesticated, 18-25% in hybrid, and 43-74% in the wild populations. However, when the influence of growth was accounted for, by dividing fish into lower and upper size modes, no difference in the incidence of MMP was detected among domesticated and wild strains in either size mode. In the lower size mode, hybrids displayed significantly lower incidences of mature males than their wild parental strains. No consistent differences in the body size of MMP, connected to domestication, was detected. CONCLUSIONS Our data demonstrate: 1- no evidence for the evolution of the size threshold for MMP in domesticated salmon, 2- the vastly lower incidence of MMP in domesticated strains under aquaculture conditions is primarily due to their genetically increased growth rate causing them to outgrow the size threshold for early maturation, 3- the incidence of MMP is likely to overlap among domesticated and wild salmon in the natural habitat where they typically display overlapping growth, although hybrid offspring may display lower incidences of mature male parr. These results have implications for wild salmon populations that are exposed to introgression from domesticated escapees.
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Affiliation(s)
- A C Harvey
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway.
| | - O T Skilbrei
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - F Besnier
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - M F Solberg
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - A-G E Sørvik
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - K A Glover
- Institute of Marine Research, P. O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Department of Biology, University of Bergen, P. O. Box 7803, N-5020, Bergen, Norway
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13
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Glover KA, Solberg MF, Besnier F, Skaala Ø. Cryptic introgression: evidence that selection and plasticity mask the full phenotypic potential of domesticated Atlantic salmon in the wild. Sci Rep 2018; 8:13966. [PMID: 30228303 PMCID: PMC6143624 DOI: 10.1038/s41598-018-32467-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 09/03/2018] [Indexed: 01/13/2023] Open
Abstract
Domesticated Atlantic salmon grow much faster than wild salmon when reared together in fish tanks under farming conditions (size ratios typically 1:2-3). In contrast, domesticated salmon only display marginally higher growth than wild salmon when reared together in rivers (size ratios typically 1:1-1.2). This begs the question why? Is this a difference in the plastic response driven by divergent energy budgets between the two environments, or is it a result of selection, whereby domesticated salmon that display the greatest growth-potential are those at greatest risk of mortality in the wild? We reared domesticated, hybrid and wild salmon in a river until they smoltified at age 2 or 4, and thereafter in fish tanks for a further 2 years. In the river, there was no difference in the mean size between the groups. In contrast, after being transferred from the river to fish tanks, the domesticated salmon significantly outgrew the wild salmon (maximum size ratio of ~1:1.8). This demonstrates that selection alone cannot be responsible for the lack of growth differences observed between domesticated and wild salmon in rivers. Nevertheless, the final size ratios observed after rearing in tanks were lower than expected in that environment, thus suggesting that plasticity, as for selection, cannot be the sole mechanism. We therefore conclude that a combination of energy-budget plasticity, and selection via growth-potential mortality, cause the differences in growth reaction norms between domesticated and wild salmon across these contrasting environments. Our results imply that if phenotypic changes are not observed in wild populations following introgression of domesticated conspecifics, it does not mean that functional genetic changes have not occurred in the admixed population. Clearly, under the right environmental conditions, the underlying genetic changes will manifest themselves in the phenotype.
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Affiliation(s)
- Kevin A Glover
- Institute of Marine Research, P.O. Box 1870, N-5817, Bergen, Norway. .,University of Bergen, Department of Biology, P.O. Box 7803, N-5020, Bergen, Norway.
| | - Monica F Solberg
- Institute of Marine Research, P.O. Box 1870, N-5817, Bergen, Norway
| | - Francois Besnier
- Institute of Marine Research, P.O. Box 1870, N-5817, Bergen, Norway
| | - Øystein Skaala
- Institute of Marine Research, P.O. Box 1870, N-5817, Bergen, Norway
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14
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Castellani M, Heino M, Gilbey J, Araki H, Svåsand T, Glover KA. Modeling fitness changes in wild Atlantic salmon populations faced by spawning intrusion of domesticated escapees. Evol Appl 2018; 11:1010-1025. [PMID: 29928306 PMCID: PMC5999203 DOI: 10.1111/eva.12615] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2017] [Accepted: 02/11/2018] [Indexed: 12/17/2022] Open
Abstract
Genetic interaction between domesticated escapees and wild conspecifics represents a persistent challenge to an environmentally sustainable Atlantic salmon aquaculture industry. We used a recently developed eco-genetic model (IBSEM) to investigate potential changes in a wild salmon population subject to spawning intrusion from domesticated escapees. At low intrusion levels (5%-10% escapees), phenotypic and demographic characteristics of the recipient wild population only displayed weak changes over 50 years and only at high intrusion levels (30%-50% escapees) were clear changes visible in this period. Our modeling also revealed that genetic changes in phenotypic and demographic characteristics were greater in situations where strayers originating from a neighboring wild population were domestication-admixed and changed in parallel with the focal wild population, as opposed to nonadmixed. While recovery in the phenotypic and demographic characteristics was observed in many instances after domesticated salmon intrusion was halted, in the most extreme intrusion scenario, the population went extinct. Based upon results from these simulations, together with existing knowledge, we suggest that a combination of reduced spawning success of domesticated escapees, natural selection purging maladapted phenotypes/genotypes from the wild population, and phenotypic plasticity, buffer the rate and magnitude of change in phenotypic and demographic characteristics of wild populations subject to spawning intrusion of domesticated escapees. The results of our simulations also suggest that under specific conditions, natural straying among wild populations may buffer genetic changes in phenotypic and demographic characteristics resulting from introgression of domesticated escapees and that variation in straying in time and space may contribute to observed differences in domestication-driven introgression among native populations.
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Affiliation(s)
| | - Mikko Heino
- Department of Biological SciencesUniversity of BergenBergenNorway
- Institute of Marine ResearchBergenNorway
- International Institute for Applied Systems Analysis (IIASA)LaxenburgAustria
| | - John Gilbey
- Freshwater Fisheries LaboratoryMarine ScotlandPitlochryUK
| | - Hitoshi Araki
- Research Faculty of AgricultureHokkaido UniversitySapporoJapan
| | | | - Kevin A. Glover
- Department of Biological SciencesUniversity of BergenBergenNorway
- Institute of Marine ResearchBergenNorway
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15
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Waples RS, Hindar K, Karlsson S, Hard JJ. Evaluating the Ryman-Laikre effect for marine stock enhancement and aquaculture. Curr Zool 2016; 62:617-627. [PMID: 29491949 PMCID: PMC5804264 DOI: 10.1093/cz/zow060] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2016] [Accepted: 05/04/2016] [Indexed: 01/06/2023] Open
Abstract
The Ryman-Laikre (R-L) effect is an increase in inbreeding and a reduction in total effective population size (NeT ) in a combined captive-wild system, which arises when a few captive parents produce large numbers of offspring. To facilitate evaluation of the R-L effect for scenarios that are relevant to marine stock enhancement and aquaculture, we extended the original R-L formula to explicitly account for several key factors that determine NeT , including the numbers of captive and wild adults, the ratio of captive to wild Ne/N (β), productivity of captive and wild breeders, and removal of individuals from the wild for captive breeding. We show how to provide quantitative answers to questions such as: What scenarios lead to no loss of effective size? What is the maximum effective size that can be achieved? and What scenarios insure that NeT will be no smaller than a specified value? Important results include the following: (1) For large marine populations, the value of β becomes increasingly important as the captive contribution increases. Captive propagation will sharply reduce NeT unless the captive contribution is very small or β is very large (∼103 or higher). (2) Very large values of β are only possible if wild Ne/N is tiny. Therefore, large wild populations undergoing captive enhancement at even modest levels will suffer major reductions in effective size unless wild Ne is a tiny fraction of the census size (about 10-4 or lower).
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Affiliation(s)
- Robin S. Waples
- National Marine Fisheries Service, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112, USA
| | - Kjetil Hindar
- Norwegian Institute for Nature Research (NINA), Trondheim 7485, Norway
| | - Sten Karlsson
- Norwegian Institute for Nature Research (NINA), Trondheim 7485, Norway
| | - Jeffrey J. Hard
- National Marine Fisheries Service, Northwest Fisheries Science Center, 2725 Montlake Boulevard East, Seattle, WA 98112, USA
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16
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Harvey AC, Solberg MF, Troianou E, Carvalho GR, Taylor MI, Creer S, Dyrhovden L, Matre IH, Glover KA. Plasticity in growth of farmed and wild Atlantic salmon: is the increased growth rate of farmed salmon caused by evolutionary adaptations to the commercial diet? BMC Evol Biol 2016; 16:264. [PMID: 27905882 PMCID: PMC5134087 DOI: 10.1186/s12862-016-0841-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 11/25/2016] [Indexed: 11/10/2022] Open
Abstract
Background Domestication of Atlantic salmon for commercial aquaculture has resulted in farmed salmon displaying substantially higher growth rates than wild salmon under farming conditions. In contrast, growth differences between farmed and wild salmon are much smaller when compared in the wild. The mechanisms underlying this contrast between environments remain largely unknown. It is possible that farmed salmon have adapted to the high-energy pellets developed specifically for aquaculture, contributing to inflated growth differences when fed on this diet. We studied growth and survival of 15 families of farmed, wild and F1 hybrid salmon fed three contrasting diets under hatchery conditions; a commercial salmon pellet diet, a commercial carp pellet diet, and a mixed natural diet consisting of preserved invertebrates commonly found in Norwegian rivers. Results For all groups, despite equal numbers of calories presented by all diets, overall growth reductions as high 68 and 83%, relative to the salmon diet was observed in the carp and natural diet treatments, respectively. Farmed salmon outgrew hybrid (intermediate) and wild salmon in all treatments. The relative growth difference between wild and farmed fish was highest in the carp diet (1: 2.1), intermediate in the salmon diet (1:1.9) and lowest in the natural diet (1:1.6). However, this trend was non-significant, and all groups displayed similar growth reaction norms and plasticity towards differing diets across the treatments. Conclusions No indication of genetic-based adaptation to the form or nutritional content of commercial salmon diets was detected in the farmed salmon. Therefore, we conclude that diet alone, at least in the absence of other environmental stressors, is not the primary cause for the large contrast in growth differences between farmed and wild salmon in the hatchery and wild. Additionally, we conclude that genetically-increased appetite is likely to be the primary reason why farmed salmon display higher growth rates than wild salmon when fed ad lib rations under hatchery conditions. Our results contribute towards an understanding of the potential genetic changes that have occurred in farmed salmon in response to domestication, and the potential mechanisms underpinning genetic and ecological interactions between farmed escapees and wild salmonids. Electronic supplementary material The online version of this article (doi:10.1186/s12862-016-0841-7) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Alison Catherine Harvey
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, UK
| | | | - Eva Troianou
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Gary Robert Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, UK
| | - Martin Ian Taylor
- School of Biological Sciences, University of East Anglia, NR4 7TJ, Norwich, UK
| | - Simon Creer
- Molecular Ecology and Fisheries Genetics Laboratory, School of Biological Sciences, Deiniol Road, Bangor University, Bangor, LL57 2UW, UK
| | - Lise Dyrhovden
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Ivar Helge Matre
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway
| | - Kevin Alan Glover
- Institute of Marine Research, P.O. Box 1870, Nordnes, NO-5817, Bergen, Norway.,Sea Lice Research Centre, Department of Biology, University of Bergen, Bergen, Norway
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17
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Leitwein M, Garza JC, Pearse DE. Ancestry and adaptive evolution of anadromous, resident, and adfluvial rainbow trout ( Oncorhynchus mykiss) in the San Francisco bay area: application of adaptive genomic variation to conservation in a highly impacted landscape. Evol Appl 2016; 10:56-67. [PMID: 28035235 PMCID: PMC5192794 DOI: 10.1111/eva.12416] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Accepted: 08/10/2016] [Indexed: 01/01/2023] Open
Abstract
The streams draining of into San Francisco Bay, California, have been impacted by habitat alteration for over 150 years, and roads, dams, water diversions, and other impediments now block the paths of many aquatic migratory species. These changes can affect the genetic structure of fish populations, as well as driving adaptive evolution to novel environmental conditions. Here, we determine the evolutionary relationships of San Francisco Bay Area steelhead/rainbow trout (Oncorhynchus mykiss) populations and show that (i) they are more closely related to native coastal steelhead than to the California Central Valley lineage, with no evidence of introgression by domesticated hatchery rainbow trout, (ii) populations above and below barriers within watersheds are each other's closest relatives, and (iii) adaptive genomic variation associated with migratory life-history traits in O. mykiss shows substantial evolutionary differences between fish above and below dams. These findings support continued habitat restoration and protection of San Francisco Bay Area O. mykiss populations and demonstrate that ecological conditions in novel habitats above barriers to anadromy influence life-history evolution. We highlight the importance of considering the adaptive landscape in conservation and restoration programs for species living in highly modified habitats, particularly with respect to key life-history traits.
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Affiliation(s)
- Maeva Leitwein
- Technopôle Brest-Iroiserue Dumont d'Urville Institut Universitaire Européen de la Mer (IUEM) University of Brest Plouzané France; Institute of Marine Sciences University of California Santa Cruz CA USA; Present address: Institut des Sciences de l'Evolution de Montpellier (ISEM) UMR 5554 Université de ´Montpellier Montpellier Cedex 5 France
| | - John Carlos Garza
- Institute of Marine Sciences University of California Santa Cruz CA USA; Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service Santa Cruz CA USA
| | - Devon E Pearse
- Institute of Marine Sciences University of California Santa Cruz CA USA; Fisheries Ecology Division Southwest Fisheries Science Center National Marine Fisheries Service Santa Cruz CA USA
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18
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Harvey AC, Juleff G, Carvalho GR, Taylor MI, Solberg MF, Creer S, Dyrhovden L, Matre IH, Glover KA. Does density influence relative growth performance of farm, wild and F1 hybrid Atlantic salmon in semi-natural and hatchery common garden conditions? ROYAL SOCIETY OPEN SCIENCE 2016; 3:160152. [PMID: 27493772 PMCID: PMC4968464 DOI: 10.1098/rsos.160152] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/02/2016] [Accepted: 05/27/2016] [Indexed: 06/06/2023]
Abstract
The conditions encountered by Atlantic salmon, Salmo salar L., in aquaculture are markedly different from the natural environment. Typically, farmed salmon experience much higher densities than wild individuals, and may therefore have adapted to living in high densities. Previous studies have demonstrated that farmed salmon typically outgrow wild salmon by large ratios in the hatchery, but these differences are much less pronounced in the wild. Such divergence in growth may be explained partly by the offspring of wild salmon experiencing higher stress and thus lower growth when compared under high-density farming conditions. Here, growth of farmed, wild and F1 hybrid salmon was studied at contrasting densities within a hatchery and semi-natural environment. Farmed salmon significantly outgrew hybrid and wild salmon in all treatments. Importantly, however, the reaction norms were similar across treatments for all groups. Thus, this study was unable to find evidence that the offspring of farmed salmon have adapted more readily to higher fish densities than wild salmon as a result of domestication. It is suggested that the substantially higher growth rate of farmed salmon observed in the hatchery compared with wild individuals may not solely be caused by differences in their ability to grow in high-density hatchery scenarios.
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Affiliation(s)
- Alison C. Harvey
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
| | - Gareth Juleff
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
| | - Gary R. Carvalho
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
| | - Martin I. Taylor
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
- Biological Sciences, University of East Anglia, Norwich, UK
| | | | - Simon Creer
- Molecular Ecology and Fisheries Genetics Laboratory, Bangor University, Bangor, Gwynedd LL57 2DG, UK
| | | | | | - Kevin A. Glover
- Havforskningsinstituttet, Bergen, Norway
- Sea Lice Research Centre, Universitetet i Bergen Institutt for Biologi, Bergen, Norway
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