Genetic growth potential, rather than phenotypic size, predicts migration phenotype in Atlantic salmon

Paul V. Debes, Nikolai Piavchenko, Jaakko Erkinaro, Craig R. Primmer

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Knowledge of the relative importance of genetic versus environmental determinants of major developmental transitions is pertinent to understanding phenotypic evolution. In salmonid fishes, a major developmental transition enables a risky seaward migration that provides access to feed resources. In Atlantic salmon, initiation of the migrant phenotype, and thus age of migrants, is presumably controlled via thresholds of a quantitative liability, approximated by body size expressed long before the migration. However, how well size approximates liability, both genetically and environmentally, remains uncertain. We studied 32 Atlantic salmon families in two temperatures and feeding regimes (fully fed, temporarily restricted) to completion of migration status at age 1 year. We detected a lower migrant probability in the cold (0.42) than the warm environment (0.76), but no effects of male maturation status or feed restriction. By contrast, body length in late summer predicted migrant probability and its control reduced migrant probability heritability by 50-70%. Furthermore, migrant probability and length showed high heritabilities and between-environment genetic correlations, and were phenotypically highly correlated with stronger genetic than environmental contributions. Altogether, quantitative estimates for the genetic and environmental effects predicting the migrant phenotype indicate, for a given temperature, a larger importance of genetic than environmental size effects.

Original languageEnglish
Article number20200867
JournalProceedings of the Royal Society B. Biological Sciences
Volume287
Issue number1931
Number of pages10
ISSN0962-8452
DOIs
Publication statusPublished - 29 Jul 2020
MoE publication typeA1 Journal article-refereed

Fields of Science

  • 1181 Ecology, evolutionary biology
  • partial migration
  • age-specific migration
  • threshold model
  • Atlantic salmon
  • smolting
  • GENERAL-METHODS
  • SALAR L
  • EVOLUTION
  • ECOLOGY
  • SMOLT
  • SMOLTIFICATION
  • HERITABILITY
  • CONSERVATION
  • PHOTOPERIOD
  • POPULATION

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