Genetic differences in physiology, growth hormone levels and migratory behaviour of Atlantic salmon smolts |
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Authors: | C Nielsen G Holdensgaard H C Petersen B Th Björnsson S S Madsen |
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Institution: | Institute of Biology, University of Southern Denmark, Main Campus: Odense University, Campusvej 55, 5230, Odense M, Denmark;Salmon Rearing and Research Station, Brusgårdsvej 15, DK-8900 Randers, Denmark;The Danish Center for Demographic Research, University of Southern Denmark, Main Campus: Odense University, Winsløwparken 17-1, DK-5000 Odense C, Denmark;Fish Endocrinology Laboratory, Department of Zoology, Göteborg University, Box 463, S-40530 Göteborg, Sweden |
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Abstract: | Out of five strains of Atlantic salmon Salmo salar of 1+ years released upstream of a fyke net in the River Gudenaa in 1996, three, Lagan, Ätran and Corrib, migrated immediately, 50% of the recaptured fish reaching the net in 3–6 days. Burrishoole and Conon fish migrated with a 15–19 day delay. Smolt development in 1997 at the hatchery showed a spring surge in gill Na+, K+-ATPase activity in all strains which was correlated with increased seawater tolerance. Differences in the timing of gill enzyme development matched the observed migration pattern well. Lagan, Ätran and Corrib strains reached high enzyme activity earlier than the Burrishoole and Conon strains, and strains with delayed enzyme development and migration showed a delayed regression of seawater tolerance compared with the early strains. Inter-strain differences in plasma growth hormone profiles could not be related to the observed patterns of Na+, K+-ATPase and seawater tolerance development. The study gives evidence of genetic influence on the timing and intensity of smolting and subsequent migration in Atlantic salmon. |
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Keywords: | smoltification Na+ K+-ATPase activity seawater tolerance migration genetics |
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