Ever since cod liver oil became a popular remedy, the livers of several species of Gadus have been used indiscriminately for its production. Even many fishermen are not able to discriminate between them. Gadus morhua, which lives in the colder waters and deeper sea regions, was the codfish species traditionally used by Rosita’s ancestors for producing truly authentic medicinal-grade cod liver oil. Gadus morhua is considered a delicacy in Norway, with a very special texture that is glassy, smooth and firm. It also has a richer taste compared to ordinary cod and falls apart on the plate in large creamy flakes when cooked. Liver oils from other types of fish, for example halibut liver oil, are higher in fat-soluble vitamins A and D. However they do not have the documented health capabilities as the Gadus morhua species of cod. Whether it’s a certain ratio of nutrients or some yet-to-be-discovered nutrient is unknown. “Cod Liver Oil and Chemistry” by F. P. Moller and “The Three Kinds of Cod Liver Oil” by L.J. De Jongh are two books written in the late 1800s detailing the dramatic healing effects of cod liver from the Gadus morhua species of cod.* Because Gadus Morhua is so prevalent in the Lofoten region of Norway, it became the hotbed of cod liver oil production in the 1800s and remains so to this day.