Maturation in Atlantic salmon (Salmo salar, Salmonidae) : a synthesis of ecological, genetic, and molecular processes

• Published in: Reviews in Fish Biology and Fisheries
• Main Authors: Mobley, Kenyon B., Aykanat, Tutku, Czorlich, Yann, House, Andrew, Kurko, Johanna, Miettinen, Antti, Moustakas-Verho, Jacqueline, Salgado, Andres, Sinclair-Waters, Marion, Verta, Jukka-Pekka, Primmer, Craig R.
• Other Authors: Organismal and Evolutionary Biology Research Programme, Evolution, Conservation, and Genomics, Biosciences, Genetics, Institute of Biotechnology, Helsinki Institute of Sustainability Science (HELSUS)
• Format: Review
• Language: English
• Published: Springer Netherlands 2021
• Subjects: Brain-pituitary-gonadal axis; Genome-wide association mapping; Life history stage; Life history traits; Puberty; Reproduction; ALTERNATIVE REPRODUCTIVE TACTICS; EARLY SEXUAL-MATURATION; LIFE-HISTORY VARIATION; ZEBRAFISH DANIO-RERIO; GONADOTROPINS GTH-I; POST-SMOLT GROWTH; SUB-ARCTIC RIVER; THRESHOLD REACTION NORMS; QUANTITATIVE TRAIT LOCI; PITUITARY-GONADAL AXIS; 1181 Ecology; evolutionary biology; 1184 Genetics; developmental biology; physiology; Arctic; Atlantic salmon; Climate change; Salmo salar
• Online Access: http://hdl.handle.net/10138/333165

Over the past decades, Atlantic salmon (Salmo salar, Salmonidae) has emerged as a model system for sexual maturation research, owing to the high diversity of life history strategies, knowledge of trait genetic architecture, and their high economic value. The aim of this synthesis is to summarize the current state of knowledge concerning maturation in Atlantic salmon, outline knowledge gaps, and provide a roadmap for future work. We summarize the current state of knowledge: 1) maturation in Atlantic salmon takes place over the entire life cycle, starting as early as embryo development, 2) variation in the timing of maturation promotes diversity in life history strategies, 3) ecological and genetic factors influence maturation, 4) maturation processes are sex-specific and may have fitness consequences for each sex, 5) genomic studies have identified large-effect loci that influence maturation, 6) the brain-pituitary-gonadal axis regulates molecular and physiological processes of maturation, 7) maturation is a key component of fisheries, aquaculture, conservation, and management, and 8) climate change, fishing pressure, and other anthropogenic stressors likely have major effects on salmon maturation. In the future, maturation research should focus on a broader diversity of life history stages, including early embryonic development, the marine phase and return migration. We recommend studies combining ecological and genetic approaches will help disentangle the relative contributions of effects in different life history stages to maturation. Functional validation of large-effect loci should reveal how these genes influence maturation. Finally, continued research in maturation will improve our predictions concerning how salmon may adapt to fisheries, climate change, and other future challenges. Peer reviewed