The influence of life-history strategy on lipid metabolism in overwintering juvenile Atlantic salmon

Morgan, I.J., McCarthy, I.D. and Metcalfe, N.B. (2002) The influence of life-history strategy on lipid metabolism in overwintering juvenile Atlantic salmon. Journal of Fish Biology, 60(3), pp. 674-686. (doi:10.1006/jfbi.2002.1886)

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Abstract

From November to May, the lipid mass in the viscera and carcass of juvenile Atlantic salmon Salmo salar that were undergoing smolt transformation prior to seaward migration (‘early migrants’) were significantly greater than those of their siblings that would delay migration for at least a further year. During winter (November-February), the depletion of lipid associated with the viscera was significantly greater in early migrants, whilst lipid depletion in the remaining carcass was greater in delayed migrants. Early migrants continued to deplete both lipid compartments in spring (February-May), whereas delayed migrants depleted visceral lipid but replenished carcass lipid over the same period. Fatty acid accumulation rates (a measure of storage lipid synthesis rates) were two to six times greater in visceral than in carcass lipid throughout the study, suggesting that lipid turnover is much more rapid in the viscera. There were no differences in fatty acid accumulation rates between migrant groups in November, despite the much lower food consumption rate of delayed migrants at that time, suggesting that these fish allocated a larger proportion of their nutritional resources to lipid synthesis. In the carcass lipid of early migrants, and in both the visceral and carcass lipid of delayed migrants, the fatty acid accumulation rate was negatively correlated with lipid mass. Fatty acid accumulation rates increased from November to February in both visceral and carcass lipid in the two migrant groups. The fatty acid accumulation rate in carcass lipid was significantly higher in delayed migrants than in early migrants in February, but not in May. These results support the hypothesis that life history strategies involving rapid growth will result in a relatively low allocation of resources to lipid reserves.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Metcalfe, Professor Neil
Authors: Morgan, I.J., McCarthy, I.D., and Metcalfe, N.B.
College/School:College of Medical Veterinary and Life Sciences > Institute of Biodiversity Animal Health and Comparative Medicine
Journal Name:Journal of Fish Biology
Publisher:Wiley-Blackwell Publishing, Inc.
ISSN:0022-1112
ISSN (Online):1095-8649
Published Online:04 April 2005

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
186572Optimal overwintering strategies in juvenile salmonNeil MetcalfeNatural Environment Research Council (NERC)GR3/10748RI BIODIVERSITY ANIMAL HEALTH & COMPMED