The Pacific yellowfin tuna, also known as AHI, is a species of tuna found in the Pacific Ocean. It is a large fish, typically weighing between 60 and 200 pounds, and is highly sought after for its meat. It is a popular game fish, and is also used for commercial fishing. The Pacific yellowfin tuna is an important part of the marine ecosystem, providing food for other species and helping to maintain the balance of the ocean's food chain.