Chart showing difference between saturated fat molecule below, and above is a polyunsaturated fat molecule. The two main features that distinguish fish oil from other animal fats are the unusually long fatty acid chains in fish oil and their high degree of unsaturation.

Image ID: fish7908, NOAA's Historic Fisheries Collection
Photographer: Artwork by Bob Hines, BCF
Credit: NOAA Central Library Historical Fisheries Collection; P. 42 of "Our Changing Fisheries" 1970 Centenary NMFS centenary volume

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