Tuna is a salt water fish from the family Scombridae, mostly in the genus Thunnus. Tuna are fast swimmers, and some species are capable of speeds of 70 km/h (43 mph). Unlike most fish, which have white flesh, the muscle tissue of tuna ranges from pink to dark red. The red coloration derives from myoglobin, an oxygen-binding molecule, which tuna express in quantities far higher than most other fish. Some larger tuna species, such as bluefin tuna, display some warm-blooded adaptations, and can raise their body temperatures above water temperatures by means of muscular activity. This enables them to survive in cooler waters and to inhabit a wider range of ocean environments than other types of fish.
1.The swimming champion in 160km in the ocean.
2.Tuna is a kind of fish which has to swim unceasingly for breathing.
3.There are about 7 kinds of tunas in the world.They inhabit in the different area of northern and Southern hemisphere.That's why they can coexist.
4.Their coloring, metallic blue on top and shimmering silver-white on the bottom, helps camouflage them from above and below.
5.They can grow to 15 feet long and weigh over 1,000 pounds. They can swim up to 50 miles per hour when pursuing prey.
