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740 results on '"Meyer, Bettina"'

261. Daily rations and growth of larval krill Euphausia superba in the Eastern Bellingshausen Sea during austral autumn.

Author

Pakhomov, E. A., Atkinson, A., Meyer, Bettina, Oettl, B., Bathmann, Ulrich, Pakhomov, E. A., Atkinson, A., Meyer, Bettina, Oettl, B., and Bathmann, Ulrich

Abstract

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.

Published
2004

285. Feeding, growth and reproduction in the genus Calanus

Author

Harris, R. P., Irigoien, X., Head, R. N., Rey, C., Meyer, Bettina, Hansen, Birte, Niehoff, Barbara, Carlotti, F., Harris, R. P., Irigoien, X., Head, R. N., Rey, C., Meyer, Bettina, Hansen, Birte, Niehoff, Barbara, and Carlotti, F.

Published
2000

289. Physiological response of adult Antarctic krill, Euphausia superba, to long-term starvation.

Author

Auerswald, Lutz, Meyer, Bettina, Teschke, Mathias, Hagen, Wilhelm, and Kawaguchi, So

Subjects
EUPHAUSIA superba, STARVATION, ENZYMES, LIPIDS, KRILL
Abstract

Adult Euphausia superba survive winter without or with little feeding. It is not exactly known whether the scarcity of food or an internal clock, set by the natural Antarctic light regime, are responsible for non-feeding. Our research questions were therefore the following: (1) How will physiological and biochemical conditions of krill change during long-term starvation at constant light regime? (2) If and how do enzyme activities change during such starvation? (3) What is the influence of food availability versus that of light regime? To answer these questions, adult krill were starved under laboratory conditions for 12 weeks with constant light regime (12:12; dark/light) and the impact on physiological functions was studied. Initial experimental condition of krill resembled the condition of late spring krill in the field with fully active metabolism and low lipid reserves. Metabolic activity and activities of enzymes catabolising lipids decreased after the onset of starvation and remained low throughout, whereas lipid reserves declined and lipid composition changed. Mass and size of krill decreased while the inter-moult period increased. Depletion of storage- and structural metabolites occurred in the order of depot lipids and glycogen reserves after onset of starvation until proteins were almost exclusively used after 6-7 weeks of starvation. Results confirmed various proposed overwintering mechanisms such as metabolic slowdown, slow growth or shrinkage and use of lipid reserves. However, these changes were set in motion by food shortage only, i.e. without the trigger of a changing light regime. [ABSTRACT FROM AUTHOR]

Published
2015
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