What is also impressive is the speed at which it swims - in sudden bursts, it can exceed 50 mph. Because of its high metabolic rate, the bluefin tuna maintains a body temperature warmer than the surrounding water. Like other tuna, bluefin belong to a large family of fish called Scombridae, which includes mackerel and bonito. As mentioned, they get quite large, but most of the fish you see in the market are smaller, ranging in size from 15-80 pounds. According to the Seafood Handbook , bluefin tuna migrate up the Atlantic coast from South America, reaching their highest fat content in the mid- to late summer when they reach New England.
Local markets have fresh bluefin tuna during the summer.
The meat is medium red in color and will be darker from larger fish. Some people still might think that you only get tuna out of a can. Many consumers have been introduced to fresh tuna and have been pleased with the difference. When tuna is cooked, it lightens considerably from its red, raw state. The texture is very firm, and care must be taken not to overcook it, for it will dry out and become tasteless.