The salt glands are osmoregulatory organs in Elasmobranchii (sharks and rays) and also in some reptiles and birds which have adapted to a marine environment or to very dry environments.
Function of the salt glands
The salt glands are generally located in the rectum (Elasmobranchii) or close to the orbits of the eye and nasal fossae (reptiles, birds) and are designed to remove excess sodium and potassium salts in order to maintain the blood's osmotic balance.
The gull excretes excess salt through the glands in its head. © Nelson Staffer CC by-nc-sa 2.0