Billfish are often considered the fastest fish in the ocean, closely rivaled by the bluefin tuna.
Billfish, a group of predatory fish characterized by their elongated upper jaws and sharp snouts, are typically regarded as the fastest swimmers in the ocean. Among them, the fastest species is the sailfish (Istiophorus). However, the bluefin tuna poses a significant threat to their title, according to IFL Science.
Sailfish are well adapted to swim at breathtaking speeds to hunt for prey. Measuring up to 3 meters from tail to snout, they belong to the family Istiophoridae, distinguished by their exceptionally large dorsal fins that resemble the sails of boats. The two species of sailfish within the Istiophorus family are the Atlantic sailfish (I. albicans) and the Indian-Pacific sailfish (I. platypterus).
The Atlantic sailfish (Istiophorus albicans), also known as Istiophorus americanus, is a species of billfish that inhabits the ocean in the family Istiophoridae. This species can grow up to 1.7 meters in length and weigh as much as 20 kilograms, with a maximum recorded length of 3.15 meters and a weight of 58.1 kilograms. They are capable of short bursts of speed reaching up to 111 km/h.
Indian-Pacific Sailfish. (Photo: Pixel).
Sailfish have a “prehistoric” appearance with a fierce look. The image of the Atlantic sailfish (Istiophorus albicans) evokes thoughts of athletes competing in sailing. This fish boasts a large dorsal fin running along the length of its body, which, when extended, resembles a sail. This large fin enables them to make sudden stops or turns while swimming at high speeds. The sail can be twice the height of the fish’s body.
The Atlantic sailfish has a metallic blue color with a sail-like dorsal fin and a long, sharp bill.
Experiments in the 1920s estimated that they could swim at speeds of up to 111 km/h in short bursts. They typically feed just below the ocean surface or at moderate depths.
This species inhabits the Atlantic Ocean, thriving in warm temperate latitudes. They are found across the Atlantic and Caribbean seas, except for vast areas in the central North Atlantic and South Atlantic, typically from the surface down to depths of 200 meters.
Sailfish typically live solitary lives.
Sailfish often roam throughout tropical and subtropical waters, spending most of their lives close to the surface. Generally, they prefer solitude, though they may occasionally swim in small groups.
Their incredible speed allows them to easily catch prey such as mackerel, herring, sardines, and pompano, using their long bills to strike at their targets. When a fish is injured or killed by this lethal strike, the sailfish quickly turns back to swallow its catch. Occasionally, they dash into a school of fish so rapidly and forcefully that they leap out of the water.
Sailfish are quite intelligent, conserving energy while hunting.
The diet of sailfish consists of various marine animals; they seem to eat almost all types of fish and smaller squid that they encounter while foraging.
Sailfish are quite clever, as they know how to conserve energy while hunting. Occasionally, they coordinate with other sailfish to hunt. They herd their prey and drive it closer to the surface, where it becomes difficult for the prey to escape. At this point, the sailfish take turns feeding while others prevent the prey from fleeing.
Each spawning event, a female sailfish can lay between 4-5 million eggs.
Sailfish spawn in the open ocean, with females releasing eggs into the water and males simultaneously releasing sperm. The eggs drift along with ocean currents. The fertilized eggs hatch relatively quickly, with larvae emerging within 1.5 days. During each spawning event, a female sailfish can lay between 4-5 million eggs, but most of these eggs do not survive to adulthood. In contrast, young sailfish grow rapidly; those that survive only take about a year to reach approximately 1.2 meters in length, and the average lifespan of a sailfish is around 10 years.
Although sailfish rank among the fastest marine animals, recent studies suggest they may not be as agile as previously thought. In the 1940s, scientists estimated that sailfish could reach speeds of up to 30 m/s, equivalent to 108 km/h. However, a study in 2015 indicated that this speed was likely exaggerated. The research team calculated that sailfish do not swim faster than 10 m/s, or 36 km/h.
It is likely that sailfish cannot maintain such speeds for extended periods. They reach maximum speed in short bursts while chasing prey. Most of the time, these large predatory fish swim at a pace comparable to a leisurely human walk.
A 2015 project by the Central American Billfish Association recorded a sailfish equipped with a tracking device (I. platypterus) accelerating at a force of 1.79 G, according to the Large Pelagic Fish Research Center at the University of Massachusetts. If the fish maintained that acceleration for just two seconds, its speed would be equivalent to 125.5 km/h.
However, bluefin tuna may challenge the sailfish’s top ranking. The Large Pelagic Fish Research Center conducted a similar study on bluefin tuna and found that they could accelerate at 3.27 G, 1.8 times the sailfish’s record. However, these are only instances of acceleration, and researchers are unclear on how long the fish can sustain that activity.
Speed records are clearer for land animals. The title for the fastest land animal belongs to the cheetah, a large cat native to Africa. The maximum speed often cited for cheetahs is 120 km/h, although this record was set decades ago and is likely outdated. In 2012, a cheetah named Sarah at the Cincinnati Zoo reached a maximum speed of 98 km/h, setting a world record.
