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

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.

桡足类（Copepod）样本采集自南极科考航次PS 79（ANT XXVIII/2），由极星号（RV Polarstern）科考船执行开普敦往返航线科考任务（2011年12月3日—2012年1月5日）。2011年12月28日，于南极威德尔海环流（Antarctic Weddell Gyre）的53号站位（南纬60°3.22′，东经0°2.14′），采用垂直邦戈网（bongo net）拖捕方式下潜至300米水深采集样本。从捕捞物中轻柔分拣得到尖刺哲水蚤（C. acutus）CV期桡足幼体210只、雌性成体160只，以及近缘哲水蚤（C. propinquus）雌性成体125只（无CV期幼体样本）。所有样本均在0℃过滤海水中活体保存于船上冷藏容器，随后以0℃冷链通过航空运输至德国。在为期9天的摄食实验中，向这些桡足类投喂碳-13（¹³C）标记的硅藻，以阐明桡足类总脂质及特定脂肪酸、醇类的同化与周转速率。通过化合物特异性稳定同位素分析（CSIA）监测¹³C在上述化合物中的掺入情况。脂质同化与周转过程的差异清晰表明，不同桡足类物种具有高度的变异性与可塑性，能够根据自身不同生命阶段调整脂质合成策略。