Lipid Profile of Krill Euphausia pacifica Collected in the Pacific Ocean near Funka Bay, Hokkaido, Japan

抄録

This paper reports the total lipid content, lipid class composition, and fatty acid composition of the krill Euphausia pacifica collected in the northwestern Pacific Ocean near Funka Bay, Hokkaido, Japan. The krill were caught in spring, summer, and winter in three consecutive years, 2000-2002. Lipid content of the E. pacifica samples was ranged from 5.1 to 11.6% on the basis of dry weight. Major lipid classes determined for the samples of 2002 were triacylglycerols (TAG) (3.4-27.3%), free fatty acids (FFA) (6.9-22.2%), sterols (5.4-12.9%), phosphatidylethanolamines (PE) (3.4-17.5%), and phosphatidylcholines (PC) (36.2-53.8%). All of the samples subjected to fatty acid analysis were high in 16:0 (19.0-24.5% of total fatty acids), 18:1n-9 (7.5-10.0%), 18:1n-7 (6.3-8.1%), 20:5n-3 (IPA) (15.3-24.7%), and 22:6n-3 (DHA) (8.4-20.7%). The lipids of E. pacifica were found to be generally rich in PC and in IPA and DHA. Lipid content and proportion of TAG were higher in the spring samples than in the summer samples. The summer samples were higher in the concentration of DHA in total fatty acids.