Tuna are one of the largest predators in the oceans. They can be found in almost every ocean in the world. There are many different kinds of tuna. Some tuna, like the blackfin tuna, weigh only 10 pounds. Others, like the bluefin tuna, can grow to a weight of 2000 pounds or more.

     Another type of tuna, the yellowfin tuna, swims in giant schools and covers great distances in search of food. With its streamlined, muscular body, yellowfin tuna are fast, efficient swimmers.

     Because they are always moving, tuna have enormous appetites. Their favorite meals consist of schools of small fish like herring or shrimp and squid.

     Tuna's special hunting technique is to encircle a large school of smaller fish and then drive them up to the water's surface. Once the small fish are near the surface, the tuna close in and eat them.

     Tuna are hunted by sharks, killer whales and humans. Each year, fishermen around the world catch hundreds of thousands of tons of tuna. Eventually these tuna make their way into cans of tuna or foods like sushi.