Daily rations and growth of larval krill Euphausia superba in the Eastern Bellingshausen Sea during austral autumn.
As the German contribution to the Southern Ocean Global Ocean Ecosystems Dynamics Study (SO GLOBEC), RVPolarstern visited the Eastern Bellingshausen Sea between 18 April and 1 May 2001. This paper examines in situ feedingcycles, ingestion rates and growth of larval krill Euphausia superba. Larval krill were exceptionally numerous, especiallyover the shelf break and continental slope: mean 8872 larvaem 2, maximum 30 084 larvaem 2. The developmentalstage composition of krill larvae over the shelf was advanced compared to that at continental slope stations, which mayhave resulted from enhanced food availability over the shelf. Despite the season being late autumn, the feeding activityof larval krill was similar to published summer rates. The intermoult period of larval krill ranged from 6 to 17 days, withdaily growth rates reaching 2.2% of body length, 8.7% of body wet mass and 5.7% of body carbon. Daily ingestionrates were 8.517.6 mgCind 1 d 1 for calyptopis 3 to furcilia 2 and 35.157.4 mgCind 1 d 1 for furcilia 35, and werepositively correlated with ambient chlorophyll a concentrations. Daily rations showed the same tendency, ranging from21.5 to 44.5% of body Cd 1 (calyptopis 3 to furcilia 2) and from 17.8 to 29.2% of body Cd 1 (furcilia 35).Comparison of daily rations between open water and sea ice stations supports the notion that larval krill at low pelagicfood supply under the sea ice have to exploit ice biota to sustain their metabolic demands.r 2004 Published by Elsevier Ltd.
Helmholtz Research Programs > MARCOPOLI (2004-2008) > POL5-Autecology of planktonic key species and groups