Ratfish liver oil is derived from the liver of a little known group of shark relatives known as the Chimaeras (Chimaera monstrosa Linnaeus; Common name: Ratfish, Rabbitfish or Ghost shark). Chimaera takes its name from the Greek chimaera, a mythical monster with the head of a lion, body of a goat, and the tail of a dragon. It is the offspring of Echinda and Typhon.
The Chimaeras are a very primitive group of fish, with skeletons composed of cartilage instead of bone, dating back for more than 300 million years. They are true survivors from before the dinosaurs, and have changed very little since. They may actually be the oldest and most enigmatic groups of fishes alive today. Truly an ancient living fossil!
The ratfish is an extraordinary fish found in all the world's oceans, close to the bottom, at depths of 300–500 meters, with a reported maximum depth of 1,663 meters. These fish are almost half shark and half ray, with smooth skin, big sparkling green eyes designed to see in the dark depths, a rabbit-like face, and a small mouth surrounded by large lips. The nose of the ratfish is studded with electric sensors able to detect the faint electrical signals given off whenever bottom dwelling prey – including crabs, snails, starfish, marine worms, urchins, clams, shrimp, and small fish – use their muscles, and sensitive enough to detect their heartbeats. Their bodies taper to an exceptionally long threadlike tail, and together with their rodent-like teeth designed for crushing the shells of their prey, has earned them the common name “ratfish.”
There is very limited fishing for this species of fish, which are not a popular food source, although they are edible and their white meat is tasteful. However, following the removal of the liver, head, and all the innards, there is actually less than 10% left for use as a food source. A major reason for this is the size of the liver, which makes up a large proportion of the total mass of the fish.
The liver of the ratfish is very large, constituting approximately 60% of its total body weight, and contains an exceedingly high proportion of oil. The oil content is around 60%, but can in some instances be as high as 80% of the wet liver weight. The large oily liver plays an important role in the maintenance of neutral buoyancy.
Ratfish liver oil is one of the finest antioxidant lubricants known, having been used for guns and fine delicate instruments. Some of the old time fishermen used to save ratfish and use the liver oil as a lubricant and rust preventer. It is extremely stable compared to most fish oils and fish liver oils, and has characteristics in common with Sperm whale oil, which was used as a lubricant for the finest pocket watches. NASA even considered ratfish liver oil as a good substitute for Sperm whale oil, which was used as a lubricant in their space program.
The oils from the ratfish were also used topically, and consumed orally, by the Norwegian Vikings and Scandinavian fishermen for centuries, who regarded this oil as a rare and very special gift from the ocean, ranking it above all other fish liver oils.
This article applies to: Rosita Ratfish Liver Oil