However, if you look under the sea there’s another animal that can give even the cheetah a run for its money in speed: the sailfish. Sailfish are members of the Istiophoridae family that also includes marlins and spearfish. They can be most easily recognized by their large sail-like dorsal fins that can run the entire length of the back. Like other members of the family, sailfish have long snouts that resemble swords and can grow to nearly 10 feet in length.
|Photo: National Geographic|
The sail on the sailfish’s back usually stays folded down when swimming, but can be raised when excited or alarmed to make the fish appear larger than it actually is. Scientists have also observed the sail being used to “herd” together the schools of fish for easier feeding. Sailfish come in a very wide variety of colors and have the unique ability to change colors almost instantly, a technique used to confuse prey and communicate with other sailfish.