Evaluation of exogenous fatty acids contributions in the lipid metabolism of the Eurasian perch (Perca fluviatilis).

This study will compare the contribution of exogenous fatty acids isotope tracers in the lipids metabolism, between the two species. In this context, we propose to investigate the desaturation-elongation of linoleic and a-linolenic acids, the fatty acid oxidation and the half-lives of these fatty acids in the main tissues involved in the lipids metabolism (muscle, liver, intestine, pyloric caeca).

After an acclimation of 4 weeks (depending of the initial weight of the fish) with a diet deprived in HUFA, all fish will be fed a diet in which fatty acids isotope tracer will have been incorporated previously (2H5-18:3n-3, 13C18:2n-6).

Isotopes concentrations will be measured by GC-MS in plasma and tissues during a time-course of one week, with sampling at 4h, 12h, 24h, 72h and 168h (one week).