SS4.07 Lipids/Fatty Acids in Ecological Research
Date: Tuesday, June 11, 2002
Location: Poster Session - VCC
BallantyneAP, Duke University, Durham, USA,
Ahlgren, G, , Uppsala University, Uppsala, Sweden, 
Grahl-Nielsen, O, , Bergen University, Bergen, Norway, 
A multi-variate analysis of fatty acids in the diet and tissues of the European Grayling (Thymallus thymallus): ecological evidence for elongation
The distribution of fatty acids was measured in several tissues of European grayling and in representative prey taxa from their diet. Principle component analysis of tissue fatty acid content revealed almost 80% of the total variance was explained by the first two principle components. Fatty acids from intestinal tissues and dorsal muscle of the grayling were mainly characterized by 18:1ω7, 18:1ω9 and 18:3ω3. Samples of heart, liver and kidney tissue were characterized by 20:3ω3, 20:5ω3, 20:4ω6, 24:0 and 24:1ω9, especially 22:6ω3. The PCA conducted on prey did not explain as much of the total variance (75.1%) within the data; however, certain noteworthy patterns did emerge The fatty acid composition of grayling gut contents was most similar to that of the aquatic invertebrates- Ephemeroptera, Plecoptera and Trichoptera. Pronounced differences in the ω 3 fatty acid distributions between tissue and prey strongly suggest the elongation of shorter length fatty acids to form EPA and DHA.