It would be good to see a picture of a fatty liver compared to a normal liver. Anyone have a fatty liver photos?
I'll see what I can do in the future as being a taxidermist I see a lot of livers in wild fish vs. the fatty livers of pellet fed fish.
That said, a fish pathologist told me "fatty liver" is a misnomoer. He says it's not the fat in the diet that causes this condition but it's too many carbs.
Dr. Brown of Purdue University says fish with these types of livers are "functional diabetics" but unlike mammals they can tolerate it better.