Spiny Dogfish & Liver Function

The spiny dogfish is the smallest of sharks.

Maturing to a length of 30 to 50 inches and a weight of 20 pounds, the spiny dogfish is the smallest of sharks. Commercially fished, this slow-growing and long-lived shark has many uses and has historically been susceptible to overfishing.

Liver Function

The oils in the liver of the spiny dogfish shark (and all sharks) help regulate its buoyancy. Deep water sharks tend to have more oil stored in their livers.

Squalene

Shark liver oils are often used in cosmetics.

Squalene is one of the main components of shark liver oils. It is used in many cosmetics, such as makeup, lotions and anti-aging creams. Sold also as a supplement, it is often touted as an anti-oxidant and cancer treatment.

Early Uses

The liver of the spiny dogfish was originally harvested for machine and lamp oils, but it was as a source of vitamin A that it had the largest economic impact. From 1940 to 1944, the spiny dogfish was fished to excess to make vitamin A. The advent of synthetic vitamin A shut down much of this market and, currently, the spiny dogfish is not considered endangered.

References

• Modeling Spiny Dogfish Population Dynamics in The Northeast Pacific: Ian G. Taylor
• Canadian Shark Research Laboratory: Spiny Dogfish
• Oceana Protecting The World's Oceans: Shark Liver Oil and Squalene