SS4.07 Lipids/Fatty Acids in Ecological Research
Date: Tuesday, June 11, 2002
Time: 10:30:00 AM
Location: Saanich
 
DESVILETTESC, Université Clermont II Lab. Biol. Protistes, Aubiere, France, Christian.DESVILETTES@lbp.univ-bpclermont.fr
VERA, A, , Université Clermont II Lab. Biol. Protistes, Aubiere, France, Aurelie.VERA@lbp.univ-bpclermont.fr
Bourdier, G, , Université Clermont II Lab. Biol. Protistes, Aubiere, France, Gilles.BOURDIER@lbp.univ-bpclermont.fr
 
SEASONAL CHANGES IN LIPID AND FATTY ACID COMPOSITIONS OF THE ALPINE DIATOMID ACANTHODIAPTOMUS DENTICORNIS
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The lipid compositions of Acanthodiaptomus denticornis from the lake Pavin (1200 m a.s.l.) were analysed. Calanoids were sampled during the development of the spring generation from early spring until winter. Nauplii and younger copepodite stages (CI-CIII) had an average lipid content of respectively 38% (DW) and 32.2% (DW) mainly consisting of triacyglycerols and wax esters. During summer late copepodite stages and adults accumulated lipids in the form of triacyglycerols. In autum and winter their lipids drawn down to lower levels as water temperature decreased and reproductive activities occured. The fatty acid composition of triacylglycerols and phospholipids were determined in the calanoids. Comparisons of these FA profiles with those obtained in phytoplankton lipids reflected ontogenetic and dietary changes as the season progressed. Nauplii and CI-CIII were feeding preferentially on diatoms but also ingested flagellates. CIV and adults were characterized by omnivorous tendancies in summer and fall while they were diatom feeders in winter.