 The viper dogfish feeds primarily on bony fishes, notably lanternfishes in the genera Benthosema and Diaphus, and also takes crustaceans. Its long jaws and slender teeth are adapted for grasping rather than cutting, in contrast to the short jaws and saw-like lower teeth of other dogfish sharks that are suited for excising chunks of meat. Prey is seized by a rapid extension of the jaws and swallowed whole; the shark can consume fish close to 40 % as long as itself. The viper dogfish is the only dogfish species that lacks a suborbital muscle, which is normally responsible for pulling the jaws forward when biting. Jaw protrusion is instead effected by the hyomandibular bone, which is articulated to the skull in a manner that allows it to swing down and forward. This unique arrangement serves to increase the distance the shark can protrude its jaws, as well as the size of its gape both vertically and horizontally.
