Pacific sailfish: Underwater speed demon breaks ocean records

It can reach up to ten feet in length and weigh dozens of pounds, and with its speed, it embarrasses even the fastest sprinters living on land. A cheetah can accelerate to 68 mph, while the Pacific sailfish can temporarily reach even 80 mph in the ocean. This astonishing fish has fascinated the scientific community for a long time.

What exactly makes the Pacific sailfish traverse the ocean depths at incredible speeds? Its entire body is powered by a mighty caudal fin, which, combined with a streamlined shape, makes the Pacific sailfish a living underwater rocket. What role does its characteristic dorsal fin play, then?

The sailfish owes its name to its dorsal fin, which resembles a sail. The fish can retract it while accelerating, but the dorsal fin is crucial during hunting. Raising the "sail" increases its maneuverability, resembling top-notch underwater acrobatics. A fish maneuvering this way stuns smaller prey with its rostrum, a beak-shaped structure.

The Pacific sailfish is even listed in the Guinness Book of Records as the fastest fish species in the world. The bluefin tuna accompany it, and it is not entirely clear which of these fish deserves the title of the fastest.

"Two species are frequently cited as prime contenders to be the fastest fish, although it is notoriously difficult to obtain accurate measurements under natural conditions," informs the Guinness Book of Records.

How, then, can we measure the speed at which the Pacific sailfish moves? One method is calculating the speed based on the length of the pulled fishing line. The number of feet of line the sailfish pulls out in a given time allows scientists to estimate the speed at which it moves.