Marlins

With their powerful, streamlined bodies, marlins are the fastest fish in the ocean, able to reach a speed equivalent to 80 miles per hour. This makesthem even quicker than the cheetah on land.

Marlins are not only able to accelerate quickly, in spite of water resistance, but they can also swim fast over long distances. This is thanks in part to the way in which blood flows around their body.Their circulation ensures that the body temperature remains several degrees above that of the surrounding water. When they are away from the shore, marlins swim in the upper part of the ocean where the sea is warmer, typically at a temperature of 68°F (20°C).

The long spike present on the upper jaw of marlins helps to identify these fish. It was once thought that this was used to spear larger prey, based on eye-witness accounts of fish impaled in this manner. But now such “catches” are believed to be accidental, because the marlin has no easy way of removing the speared fish from the spike so it can be swallowed.

A Perilous Lifestyle

Most marlins live on their own for much of the year, although younger individuals sometimes gather in small groups. Adults will migrate, however, heading across the oceans to their traditional spawning grounds. From the huge numbers of eggs an adult female marlin produces, only a tiny percentage will develop into fish that will survive long enough to breedthemselves. They face many dangers in the open ocean—from other fish when young, to fishermen who prize marlins when adult as sporting trophies.