Seasonal variations in lipids and fatty acid compositions of frigate mackerel Auxis rochei

The seasonal variations in lipids and fatty acid compositions of frigate mackerel Auxis rochei caught off Kochi Prefecture were examined from the viewpoint of the effective utilization of fish wastes. The lipid contents varied from 5.2 to 11.6% for the head, which accounted for about 42% of fish wastes, and from 7.0 to 17.9% for the orbital tissue throughout the year. Docosahexaenoic acid (DHA) was the major unsaturated fatty acid and accounted for more than 22.7% and 24.5% of the total fatty acids in the lipids of the head and orbital tissue, respectively. This result indicated that head portion including the orbital tissue may be useful source of DHA production.