The bluntnose sixgill shark, Hexanchus griseus, often simply called the cow shark, is the largest hexanchoid shark, growing to 16 ft (4.9 m) in length. This shark is one of the commonly studied deep-sea sharks, due to students using bait (tuna or carrion) to perform tests to see how deep-sea fish find their food in the light-less world of the deep sea.