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Lipids as trophic markers in Antarctic krill. III. Temporal changes in digestive gland lipid composition of Euphausia superba in controlled conditions

Citation

Alonzo, F and Virtue, P and Nicol, S and Nichols, PD, Lipids as trophic markers in Antarctic krill. III. Temporal changes in digestive gland lipid composition of Euphausia superba in controlled conditions, Marine Ecology Progress Series, 296, (July 12) pp. 81-91. ISSN 0171-8630 (2005) [Refereed Article]

DOI: doi:10.3354/meps296081

Abstract

Two phytoplankton diets with markedly different fatty acid (FA) profiles (thraustochytrid and diatom over a range of concentrations) were fed to juvenile Euphausia superba Dana to evaluate the time lapse required for the development of trophic lipid signatures in the digestive gland (DG). Krill were collected after 5, 10 and 20 d of feeding on thraustochytrids. Krill fed on thraustochytrids for 20 d were also collected after a further 5, 10 and 00 d of feeding on diatoms. An accumulation of polar lipid (0.4 mg per DG) was observed after 5 d of feeding on thraustochytrids at every concentration of food. The deposition of triacylglycerol (0.25 mg per DG) required 10 d of feeding and only occurred at the 2 highest food concentrations. Amounts of thraustochytrid- derived FA, 14:0, 16:0 22:6ω3 and 22:5ω6, increased after 10 d of feeding. The final concentration of 22:6ω3 was dependent on food concentration. Though it was absent in the diet, the essential FA 20:5ω3 accumulated from the retroconversion of 22:6ω3 after 20 d. Changing the krill diet to diatoms resulted in a marked decline in thraustochytrid FA, particularly 14:0 and 22:6ω3, after 5 d, whilst diatom FA, 16:1ω7 and 20:5ω3, remained constant. Thraustochytrid signatures were completely erased from the FA profiles of DG after 20 d feeding on diatoms. Slow accumulation of storage lipid and short residence time of dietary FA suggest that lipid turnover rates are high in Antarctic krill DG. © Inter-Research 2005.

Item Details

Item Type:Refereed Article
Research Division:Biological Sciences
Research Group:Ecology
Research Field:Marine and Estuarine Ecology (incl. Marine Ichthyology)
Objective Division:Environment
Objective Group:Flora, Fauna and Biodiversity
Objective Field:Marine Flora, Fauna and Biodiversity
Author:Alonzo, F (Dr Frederic Alonzo)
Author:Virtue, P (Associate Professor Patti Virtue)
Author:Nichols, PD (Dr Peter Nichols)
ID Code:39137
Year Published:2005
Web of Science® Times Cited:6
Deposited By:IASOS
Deposited On:2005-08-01
Last Modified:2012-03-05
Downloads:0

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