The Atlantic bluefin tuna is one of the world's largest, fastest and most colorful fish. It has a torpedo-shaped body built for speed. Humans have been eating this fish for hundreds of years, but in the 1970s, demand for them went up. Since then, they have been a prize among sport fishers. In fact, in January 2001, a 444-pound bluefin tuna sold in Japan for $173,600 (a world record).