Assimilation rates, compound-specific stable isotope analysis and fatty acid data of dominant Antarctic copepods

Copepod samples were taken during the Antarctic expedition PS 79 (ANT XXVIII/2) with RV Polarstern (Cape Town – Cape Town, 3 Dec 2011 – 5 Jan 2012). Copepods were collected at Station 53 (60° 3.22'S, 0° 2.14' E) in the Antarctic Weddell Gyre on 28 December 2011 by vertical bongo net hauls down to 300 m depth. Specimens of C. acutus (210 copepodids CV and 160 females) and of C. propinquus (125 females, no CV stages available) were gently sorted from the catch, maintained alive in filtered seawater at 0°C in a cooling container on board and transported to Germany at 0°C by airplane. Feeding carbon-labelled diatoms to these copepods during 9 days of feeding ,13C elucidated assimilation and turnover rates of copepod total lipids as well as specific fatty acids and alcohols. The 13C incorporation into these compounds was monitored by compound-specific stable isotope analysis (CSIA). The differences in lipid assimilation and turnover clearly show that the copepod species exhibit a high variability and plasticity to adapt their lipid production to their various life phases.