A GT fish is a common abbreviation for the giant trevally (Caranx ignobilis), which is a large marine fish classified in the jack family, Carangidae. It is also known as giant kingfish, barrier trevally, lowly trevally, ulua (in Hawaii), and is a powerful predator that can grow up to 67 inches (170 cm) long. The giant trevally is typically associated with coral reef communities and is a top-level carnivore in reef systems, feeding on animals like fish, cephalopods, birds, and crustaceans. It is also an important fish for commercial and recreational fisheries, as well as aquaculture. The species is known for its fighting spirit and is a popular sport fish among anglers.