The family Hexanchidae, also called cow sharks, is a unique family of sharks characterized by an extra pairs of gill slits. Cow sharks are considered the most primitive of all the sharks because their skeletons resemble those of ancient extinct forms. Members of this family range from 4.6' to 16' in length. Cow sharks are ovoviviparous, with the mother retaining the egg-cases in her body until they hatch. They feed on relatively large fish of all kinds, including other sharks, as well as on crustaceans and carrion.
ITEMS in the Family: Hexanchidae