Die Flügelschnecke Clione limacina: Außergewöhnliche Lipide als Anpassungsstrategie an den Lebensraum Arktis
The main topic of this thesis was to investigate of the ecological role of lipids in the life-strategy of the pteropod Clione limacina and the adaptations to the Arctic environment. Since the sea butterfly Limacina helicina is the only food of C. limacina and the development of both species occurs s...
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| Other Authors: | , |
| Format: | Doctoral or Postdoctoral Thesis |
| Language: | German |
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Universität Bremen
2005
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| Online Access: | https://media.suub.uni-bremen.de/handle/elib/2170 https://nbn-resolving.org/urn:nbn:de:gbv:46-diss000101326 |
| Summary: | The main topic of this thesis was to investigate of the ecological role of lipids in the life-strategy of the pteropod Clione limacina and the adaptations to the Arctic environment. Since the sea butterfly Limacina helicina is the only food of C. limacina and the development of both species occurs simultaneously, lipid biochemical investigations of L. helicina are as well important for the assessment of the life-strategy of C. limacina. The basic questions of this thesis were studied by combining field work and experiments. The results about the seasonal lipid dynamics of C. limacina and L. helicina clearly demonstrate that lipids play a key role in both species during the ontogenetic development and reproduction. Limacina helicina is a true omnivore feeding on available particles. The fatty acid composition reflects its diet which ranged from mostly phytoplankton in spring and summer to degraded organic material in late autumn and winter. In autumn the large females of L. helicina die after spawning, and the lipid-rich veligers develop to juveniles which both are overwintering stages. For Clione limacina the seasonal field studies have shown that the fatty acids originating from the food correlate with tri-acylglycerols (TAG), whereas the odd-chain fatty acids and the monounsaturates 16:1(n-7) and 18:1(n-7) correlate with 1-O-alkyldiacylglycerols (DAGE) and hence were mostly synthesised de novo. Both lipid classes were depleted during the ontogenetic development, maturation and reproduction in summer which underlines their importance as energy source within these processes. Due to enhanced accumulation of DAGE during autumn and a more slowly catabolism than TAG during long-term starvation this lipid class is most likely of major importance during food scarcity and over-wintering. Until now only little is known about the life-cycle of the Arctic Clione limacina. The length-frequency distribution of C. limacina revealed no unequivocal population structure why it was assessed by principal component analysis (PCA). ... |
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