The black jack lives either individually or in small schools and is known to school with other species. It is a predatory fish, taking a variety of fish, crustaceans and mollusks as prey. These species' common names all refer to the black hue displayed by the fish, with the name 'black jack' most commonly used. Other names include 'black trevally', 'black kingfish', 'coal fish' and 'black ulua' in Hawaii.