Bigeye tuna, also known as AHI (3 letters), is a species of tuna found in tropical and subtropical waters around the world. It is an important commercial fish, highly valued for its high fat content and firm texture. Bigeye tuna can grow up to 1.5 meters in length and weigh up to 200 kilograms. It is an apex predator, feeding on smaller fish, squid, and crustaceans. Bigeye tuna is an important part of many cultures' diets, and is also popular in sushi and sashimi.