Lipid dynamics and feeding of dominant Antarctic calanoid copepods in the eastern Weddell Sea in December |
| |
Authors: | Anna Pasternak Wilhelm Hagen Gerhard Kattner Jan Michels Martin Graeve Sigrid B Schnack-Schiel |
| |
Institution: | (1) Shirshov Institute of Oceanology, Russian Academy of Sciences, 117997 Moscow, Russia;(2) Department of Marine Zoology, University of Bremen, 28334 Bremen, Germany;(3) Alfred Wegener Institute for Polar and Marine Research, 27570 Bremerhaven, Germany |
| |
Abstract: | Lipid content, fatty acid composition, and feeding activity of the dominant Antarctic copepods, Calanoides acutus, Calanus propinquus, and Metridia gerlachei, were studied at a quasi-permanent station in the eastern Weddell Sea in December 2003. During 3 weeks of the spring phytoplankton
development, total lipid levels of females and copepodite stages V (CVs) of C. acutus were almost doubled. Meanwhile, only a slight increase in total lipid content occurred in M. gerlachei, and no clear trend was observed in lipids of C. propinquus females. The pronounced increase of lipids in C. acutus was due to an accumulation of wax esters. The proportion of wax esters in the lipids of M. gerlachei was clearly lower, while triacylglycerols played a more important role. In C. propinquus, triacylglycerols were the only neutral lipid class. There were no pronounced changes in the feeding activity of M. gerlachei, whereas the feeding activity of C. acutus had rapidly increased with the development of the phytoplankton bloom in December, which explains its rapid lipid accumulation.
The combination of gut content and fatty acid trophic marker analyses showed that C. acutus was feeding predominantly on diatoms. The typical diatom fatty acid marker, 16:1(n-7), slightly decreased and the tracer
for flagellates, 18:4(n-3), increased in females and CVs of C. acutus. This shift indicates the time, when the significance of flagellates started to increase. The three copepod species exhibited
different patterns of lipid accumulation in relation to their trophic niches and different duration of their active phases.
The investigations filled a crucial data gap in the seasonal lipid dynamics of dominant calanoid copepods in the Weddell Sea
in December and support earlier hypotheses on their energetic adaptations and life cycle strategies. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|