Lipid biochemistry of Antarctic euphausiids: energetic adaptions and a critical appraisal of trophic biomarkers

• Other Authors: Stübing, Dorothea
• Language: English
• Published: Staats- und Universitätsbibliothek [Host] 2004
• Subjects: Antarctic; Antarc*; Antarctic Krill; Euphausia superba
• Online Access: http://nbn-resolving.de/urn:nbn:de:gbv:46-diss000009929; http://webdoc.sub.gwdg.de/ebook/diss/Bremen/2004/E-Diss992_stuebing.pdf

Antarctic krill, Euphausia superba, lipids, fatty acids, trophic markers, phosphatidylcholine. - The energetic and physiological condition of various ontogenetic stages of Antarctic euphausiids was examined at the onset of winter. Field and experimental data were used to evaluate the relative importance of alternative overwintering strategies for Euphausia superba. Furcilia III larvae had low lipid levels, mainly phospholipids (PL), high metabolic and feeding activities, with the main diet being diatoms. Hence, the larvae exhibited a ʺbusiness as usualʺ strategy. A clearly deviating behaviour was observed in juvenile and adult E. superba, with high lipid depots, mainly as triacylglycerols and PL, and low metabolic and feeding rates as compared to summer values. These data indicated a compromise overwintering strategy between switch feeding and energy conservation for postlarval E. superba.Long-term feeding experiments were carried out to examine the effect of various diets on the lipids and stable isotopes of larval, juvenile, and adult E. superba. Total lipid content, lipid class, fatty acid and stable isotope compositions showed very little variation with the different feeding regimes in postlarval krill. The weak signal of the trophic marker . @Bremen, Univ., Diss., 2004