Long-Chain Monoethylenic and Other Fatty Acids in Heart, Liver, and Blubber Lipids of Two Harbor Seals (Phoca vitulina) and One Grey Seal (Halichoerus grypus)

Abstract

The fatty acids of triglycerides in the hearts from two harbor seals (Phoca vitulina) and one grey seal (Halichoerus grypus) differed quantitatively in some details from those in the blubber. The 22:1 found in the heart triglycerides was about half that in the blubber triglycerides. Isomer distributions differed within 20:1 acids in the two triglycerides for both species, the higher proportion of 20:1ω11 fatty acid deposited in the heart than in the blubber indicating more active chain shortening from 22:1. The fatty acids of phospholipids of all three hearts and livers also differed quantitatively in some fatty acid details indicating organ-specific compositions. These also differed from compositions of similar lipids in terrestrial animals in their generally marine fatty acid compositions which were established for the blubbers. The grey seal (age 3 mo) showed unusual percentages of linoleic types of acids in the organ lipids and also a curious enrichment in ω7 monoethylenic acids. Dietary factors are believed to be responsible for differences between this animal and the two harbor seals (ages 10 and 23 mo).