I know very well about sources of linoleic acid, but none of these are sources of EPA/DHA, the actual form the body needs.
What I'm talking about is this:
D6D
"In addition, some individuals are not genetically programed to produce D6D at all, mainly those whose ancestors had lots of preformed D6D metabolites from organ meats and fish in their diets. Researchers have called such individuals “obligate carnivores.” They are especially prone to diseases like diabetes and alcoholism if they do not eat enough fish and organ meat."