Dietary Transfer of Fatty Acids in Fish

Fatty acid signature (FAS) analysis is a powerful tool to investigate foraging ecology and food web dynamics. However, the use of FAS to infer diets is influenced by lipid metabolism in predators. Therefore, we investigated how fatty acids were transferred from prey to predator and metabolized through two experiments. In experiment 1, lake trout were fed rainbow smelt for 16 weeks whereas in experiment 2 yellow perch were fed Mysis or bloodworm for 36 weeks. Fish were sampled throughout the experiment for FAS analysis. The results indicated that exclusive diet was enough to change FAS in both lake trout and yellow perch. However, due to the species specific fatty acid metabolism, yellow perch and lake trout FAS were still distinguishable from the one of their respective diets.