DHA content in dietary phospholipids affects DHA content in phospholipids of cod larvae and larval performance

AbstractThe objectives of the study were to examine if early cod larvae could incorporate long-chain highly unsaturated fatty acids like docosahexaenoic acid (22:6 n−3, DHA) from dietary phospholipids (PL) more efficiently than from dietary triacylglycerides (TAG), and to investigate if because of this, PL from copepods is a better DHA source than PL from rotifers for larval cod. Two diets of Brachionus plicatilis Nevada were compared in one first feeding experiment. Their lipid composition was similar, but %DHA of PL fatty acids was different; 2.1% for Brachionus-Low and 9.4% for Brachionus-High. A second experiment compared the Brachionus-High diet (9.4% DHA in PL) and cultivated nauplii of Acartia tonsa that contained 30% DHA of PL-fatty acids. The total lipid per fry dry weight (DW) and the lipid class composition were similar for all larval groups at 17days post-hatching (dph). The %DHA of total fatty acids in PL of newly hatched larvae (2dph) was 26%, and the values for fed groups varied from 17 to 30% DHA of PL fatty acids. The dominant fatty acids in the PL of larvae and PL of the diets were well correlated (r2=0.84, p