The lipids from 22 species of fish and mollusk were examined.
In the fatty acid compositions of fish lipids the monoenoic acid was the most predominant component.
Although the marine fish lipids resembled the fresh-water fish lipids as to the contents of total monoenoic acids and of 18:1 acid, the former was rich in 20:1 and 22:1 acids, and the latter in 16:1 acid. Of the polyenoic acid 20:5 and 22:6 acids predominated in marine fish lipids, but in the fresh-water fish lipids, smaller amounts of 20:5 and 22:6 acids, and larger amounts of 18:2 and 18:3 acids were found.
The flesh and viscera lipids of ‘KICHIJI’, spiney-cheek, contained a much larger amount of 18:1 acid and smaller amounts of 20:5, 22:6 and 16:0 acids than the average values in marine fish lipids.
These characteristics in the fatty acid composition of ‘KICHIJI’ lipid are common to the lipids of deep-sea fish, and are considered to be related to the mesopelagic origin of ‘KICHIJI’.