The yellowfin tuna (Thunnus albacares), is a type of tuna. It is foun in open waters of tropical and subtropical seas worldwide. It is an epipelagic fish ranging in the top 100 m (330 feet) of the water column. Reported sizes have ranged as high as 239 cm (94 inches) in length and 200 kg (440 lb) in weight. Also known as ahi tuna, from its Hawaiian name ʻahi, yellowfin is becoming a popular replacement for the severely depleted supplies of bluefin tuna.