Fatty acid composition of Pacific walrus skin and blubber fats

Abstract
The fatty acid composition of skin and blubber lipids was analyzed from four apparently healthy adult Pacific walrus (Odobenus rosmarus divergens) taken in the Bering Sea and one moribund walrus from the vicinity of Barrow in the northern Chukchi Sea. All specimens had similar fatty acid complements; 13 fatty acids predominated ranging from chain lengths of 14 to 22 carbons with zero to six double bonds. There were no major differences between males and females nor between the one lactating and the nonlactating female. There were specific differences from inner blubber to outer blubber and skin and between the four healthy and one moribund animal. Double-bond indices (indicating degree of unsaturation) were relatively high in all samples, which reflects the large amount of long-chain polyunsaturated acids in the skin and blubber lipids. Inner blubber lipids were more highly unsaturated than outer blubber or skin lipids similar to the patterns observed in baleen whales. Melting points of blubber lipid ranged from 2.2 to −6.8 °C for some components; all components melted below 21.5 °C. Fatty acid composition of hind flipper tissues did not differ significantly from those in the trunk skin and blubber.