LIPID AND FATTY-ACID CONTENT IN CULTIVATED LIVE FEED ORGANISMS COMPARED TO MARINE COPEPODS

The total lipid content in Artemia franciscana (21-23% of dry weight ( DW)) when enriched with either Super Selco or DHA Selco was twice as h igh as in the adult copepods Temora longicornis and Eurytemora sp. (9- 11% of DW). In Brachionus plicatilis the total lipid content was 11 an d 6.6% for cultures growing at high and low growth rate, 0.12 d(-1) an d 0.38 d(-1), respectively. In the copepodid stages I, II and III of C alanus finmarchicus the total lipid level was 12-13%, increasing to 24 % in copepodid stage IV, V and the adults. In T. longicornis and Euryt emora sp. the predominant fatty acids were DHA (22:6n-3), EPA (20:5n-3 ) and the saturated fatty acid 16:0, which constituted 40-45%, 21-24% and 8-12% of total fatty acids, respectively. C. finmarchicus containe d the same dominant fatty acids. In both the cultivated live feed orga nisms DKA, EPA and 18:1 were the predominant fatty acids. In A. franci scana the content of these fatty acids varied according to the enrichm ent medium and in B. plicatilis according to the growth rate.