Sailfish fishing: the fastest fish in the world — measured on a fishing line

October 8, 2026

In almost every list of the fastest animals in the sea, one fish sits right at the top: the sailfish. The Swedish, Dutch and Hebrew Wikipedia give 109 km/h, the Portuguese one 110 km/h — citing the Guinness Book —, the Spanish one 119 km/h. Where the figure comes from is told by the Russian Wikipedia: from a series of tests at a fishing camp on Long Key in Florida, in which a sailfish covered 91 metres in 3 seconds. The French Wikipedia says more precisely what was running: 91.4 metres of fishing line in three seconds — and notes that a citation is missing. The English one speaks of tests in the 1920s. So the most famous speed record in the fish world was set by a fishing reel. According to the Russian Wikipedia, newer studies arrive at a third of it. And for the Mediterranean this fish has a second story: according to FishBase, it comes in through two doors. This article is about the sailfish, genus *Istiophorus* — German Fächerfisch (also Segelfisch), French voilier, Spanish pez vela, Italian pesce vela, Portuguese peixe-vela, Japanese バショウカジキ (bashōkajiki).

The record a fishing reel set

The German Wikipedia cautiously calls the old values “allegedly”: 40 to 59 knots, around 75 to 110 km/h. More recent studies, it writes, cast strong doubt on them; according to these, the sailfish does not exceed 36 km/h, and a new study puts the theoretically attainable top speed at 36 to 45 km/h. The English Wikipedia even gives 35 metres per second, around 125 km/h, as an earlier estimate; studies from 2015 and 2016 arrived at no more than 10 to 15 metres per second (35 to 55 km/h). While hunting prey, sprints of 7 metres per second were measured — about 25 km/h —, and none was above 10 metres per second. The Japanese Wikipedia goes furthest: measured at sea, the sailfish swam at an average of around 2 km/h, and fish tracked with transmitters reached at most about 8 km/h — with the honest addition that nobody can say whether a fish was really going flat out at the time. Built for speed it is all the same: at high speed it folds its sail into a groove along the back, as well as the anal fin and the long pelvic fins (the Russian and the German Wikipedia). According to the Russian Wikipedia it has no swim bladder.

How to recognise it

According to the German Wikipedia, the identifying mark can be seen even from the boat when it swims just below the surface: the huge, sail-like first dorsal fin, taller than the body is deep at its deepest point. It starts at the back of the head and reaches almost to the small second dorsal fin; according to the English Wikipedia it is cut off straight at the front and highest in the middle. The body is elongated and strongly compressed laterally (the German Wikipedia). The upper jaw extends into a long, slender bill that is round in cross-section — as in all marlins and unlike the swordfish (the German Wikipedia, FishBase). Jaws and palate carry fine, brush-like teeth; gill rakers are absent (FishBase). The pelvic fins are very long and narrow, reach almost to the anus and can be folded into a groove. The caudal peduncle carries two keels on each side, and the skin small, embedded scales with one or two blunt points (FishBase).

The colour: dark above, below that about 20 bluish stripes, the belly pale silvery (FishBase). The membrane of the sail is blue-black and covered with many dark spots; the base of the anal fins often shines silvery white, and the other fins are blackish brown or dark blue (FishBase). Which way the stripes run is less clear than it sounds — see below. And it can change them: according to the English Wikipedia, some sources report that sailfish change colour to confuse prey, to show their mood or to communicate with each other; according to the Italian Wikipedia, the skin turns lighter or darker depending on its state of mind, and sometimes stripes appear on the back.

Size: for the Indo-Pacific sailfish, *Istiophorus platypterus*, FishBase gives 348 cm (fork length) as the maximum, 270 cm as the common length and 100.2 kg as the heaviest published weight — which matches the sport-fishing record named by the French Wikipedia: 100.24 kg, caught in 1947 off Santa Cruz island in Ecuador. For the Atlantic one, *Istiophorus albicans*, FishBase gives 315 cm, commonly 240 cm, and at most 58.1 kg. Females grow larger; according to the French Wikipedia this is the only visible difference between the sexes, according to the German one very large specimens are always females.

Through two doors into the Mediterranean

Whether there is one sailfish or two is disputed (see below) — FishBase lists two, and for the Mediterranean that is revealing. About the Indo-Pacific one, FishBase writes that it has immigrated into the Mediterranean from the Red Sea through the Suez Canal; the English Wikipedia calls it a Lessepsian migrant, and the German and the Russian one say the same. About the Atlantic one, FishBase writes: it migrates into the Mediterranean — recorded mostly through juveniles. The Italian Wikipedia, too, reports mainly young specimens caught in the Mediterranean. The first door, then, is the Suez Canal in the east, the second the Strait of Gibraltar in the west. And the German Wikipedia says one more thing: apart from the Mediterranean, the two populations touch only off the coast of South Africa and can mix there. That makes the Mediterranean one of only two places where the two sailfishes meet — if there are two at all.

What none of the sources says: how common it is in the Mediterranean. None names a Mediterranean fishery, none a season, no ground. The big sailfish grounds that the sources name lie elsewhere: according to the Russian Wikipedia off Florida, Cuba, California, Hawaii, Tahiti, Peru, New Zealand and Australia and in the Seychelles, according to the Japanese one in the South China Sea around Taiwan, the Philippines and Malaysia, according to the Spanish one off Manzanillo in Mexico. For the Atlantic off Africa, the French Wikipedia names the largest sailfish caught there, 64.6 kg off Lobito in Angola (2014), and spawning all year round over the West African shelf.

Where it lives and what it eats

Distribution: for the Indo-Pacific one, FishBase gives 50° North to 43° South; for the Atlantic one about 40° North in the northwestern, 50° North in the northeastern, 40° South in the southwestern and 32° South in the southeastern Atlantic. In Russia it is rare according to the Russian Wikipedia and occurs off the southern Kurils and in Peter the Great Gulf; in Japan, according to the Japanese Wikipedia, south of Tōhoku, rarely as far as southern Hokkaidō.
Water: it prefers 21 to 28 °C and stays mainly above the thermocline, but can also dive deeper (FishBase, the German Wikipedia). FishBase gives 0 to 200 metres, mostly from 30 metres.
Closeness to land: of all marlins, according to the Japanese Wikipedia, it comes closest to the coast. According to FishBase it is most abundant near coasts and islands; the Atlantic one often moves into inshore waters. The English Wikipedia notes a strong tendency towards coasts, islands and reefs — and, as observed in the Persian Gulf, it can disappear when the coral reefs disappear.
Diet: mainly fish, plus crustaceans and cephalopods (FishBase). The German Wikipedia lists sardines, halfbeaks, mackerels, cutlassfish, jacks, sea breams and gurnards, plus paper nautiluses. According to the French Wikipedia, off Florida it eats among other things the little tunny, off Taiwan mainly the bullet tuna (*Auxis rochei*) — two small tunas to which this series devotes articles of their own. Off Mazatlán in Mexico, remains of large squid were found in 67% of the stomachs examined; in the Indian Ocean, fish in 81%, crabs in 31% and squid in 25% (the French Wikipedia). It also takes animals from the bottom (FishBase), according to the French Wikipedia such as gurnards, cephalopods and snails.
Hunting partners: according to the German Wikipedia it often hunts together with dolphins, sharks, marlins, tunas and dolphinfish.
Enemies: freshly hatched, it is hunted by plankton feeders; adult sailfish, according to the English Wikipedia, are eaten only by large oceanic sharks and orcas.
A lodger: at the Aquamarine Fukushima aquarium, according to the Japanese Wikipedia, a remora was observed cleaning a sailfish of parasites and in return being allowed to live under its gill cover.

The hunt: sail up, bill sideways

According to the English Wikipedia, the sail stays folded down while swimming and goes up only during the attack. It then dampens the sideways oscillations of the head — the bill stays harder to see for the prey, and the sailfish can bring it close to the school or even into it before striking. The German Wikipedia compares the sail to the keel of a boat. There are two ways to strike: a short tap or a wide, horizontal slash (the English Wikipedia). It shoots into the school with its pelvic fins folded, brakes with its fins spread in a sharp turn and eats the fish it has hit head first (the German Wikipedia). On average, each attack injures two prey fish, but only 24% of attacks end in a catch (the English Wikipedia). Because injured fish slow down, every sailfish benefits from the slashes of the others — researchers call this protocooperation. The fish usually attack one at a time, and each has a favourite side: some slash to the left, others to the right, and those with a strong preference catch more. Because both types are about equally common in a group, the school cannot predict where the next slash will come from (the English Wikipedia). Fleeing sardines turn away, so the sailfish usually attacks them from behind — where the injured, slower fish gather.

The sail may have a second job: according to the English and the Hebrew Wikipedia, marine biologists suspect that it serves for heating and cooling — it is laced with many blood vessels, and sailfish often raise it before or after fast sprints at the surface. The Russian Wikipedia describes how they drift slowly at the surface with the sail fully raised above the water. That is also where the names come from: according to FishBase, *Istiophorus* means “sail bearer”, from the Greek istios (sail) and pherein (to carry). The Japanese name バショウ (bashō), according to the Japanese Wikipedia, compares the sail to the leaf of a banana plant with its straight leaf veins.

A metre in the first year — and millions of eggs

Sailfish grow fast: according to the English Wikipedia 1.2 to 1.5 metres in a single year, according to the Russian one even 1.5 to 2 metres. The French Wikipedia gives 100 cm at two years and sexual maturity at two and a half years; for the Atlantic one, FishBase gives a length at first maturity of 133.5 cm. According to FishBase, spawning takes place in the tropics and subtropics of the Pacific all year round, most of all in the local summer — in pairs or with two or three males following one female. Off Florida the fish move into shallow, inshore water to spawn: the females swim sluggishly with their sail raised, accompanied by one or more males (FishBase). A female weighing 33.4 kg released up to 4.8 million eggs there in one season, in three batches (FishBase, the German Wikipedia). The eggs measure 0.85 to 1.3 mm and carry an oil droplet that keeps them afloat (FishBase, the German Wikipedia). For the fish off Japan, the Japanese Wikipedia gives April to August east of the Philippines; in juveniles the first and second dorsal fins are still joined and only separate as they grow. The Russian Wikipedia simply gives August to September.

How it is caught — and what you should know

FishBase lists it as a game fish and as commercial; it is caught mainly on longlines and in gillnets, sometimes by trolling and with the harpoon. According to the English Wikipedia, it mostly ends up as bycatch on the longlines of the tuna fleets, is considered less valuable than marlins and is usually released; sport anglers prize it as a hard-fighting fish. Because of all marlins it is the most likely to turn up near the coast, it is popular for trolling according to the Japanese Wikipedia. The Spanish Wikipedia describes the fight: powerful runs under water and spectacular leaps; it is fished with live and dead bait, with trolling lures and artificial squid. The Russian Wikipedia tells that Ernest Hemingway was among its anglers and that a fishing tournament is held in his memory every year in Havana. The Finnish Wikipedia describes a method from Mexico without any hook at all: a roughly 30 cm long, frayed piece of rope is towed behind the boat, and the sailfish gets its bill tangled in the fibres. The Finnish source explains this with “suction cups” on the bill — FishBase and the German Wikipedia know only fine teeth there. And a warning from the English Wikipedia: a 45 kg sailfish stabbed a woman in the groin when her group tried to catch it.

⚠️ What follows is an inference from its biology, not a sourced statement: a fish that hunts above the thermocline in water of 21 to 28 °C, comes closest to coasts and islands of all marlins and follows schools of small fish is searched for where baitfish hold in warm surface water. A fish that, according to FishBase, reaches just under 60 kg in the Atlantic is lighter than a marlin, but calls for a fast fight full of jumps. In the Mediterranean, by everything the sources say, it is a rare visitor — whoever catches one there has a rarity on the line: take a photo, keep the fight short, release it in the water. And because it is vulnerable and the bill can cause injuries: keep your hands off the tip of the bill, and don’t lift the fish into the boat if it is going back.

For the kitchen: FishBase rates it as harmless; it is used fresh, smoked and frozen, also for sashimi and sushi, grilled or baked. The Japanese Wikipedia describes the flesh as fibrous, lean and red, tasty above all in summer and autumn, but less refined than that of other marlins; how fresh it stays depends heavily on how quickly the fish is killed after the catch — fishermen grab it by the bill for this and stun it with a blow to the head. The Italian Wikipedia calls the flesh tasty and the liver rich in vitamin A.

And the stock? The IUCN lists the sailfish as “Vulnerable” (FishBase: assessed on 1 May 2021) and, according to the English Wikipedia, treats it as one worldwide species. FishBase lists the Atlantic one as “not evaluated”; the Spanish Wikipedia even calls both endangered. According to the German Wikipedia, the stock in the Indian Ocean makes up around 87% of the world stock and is overfished, with a decline of 27 to 33% in 12 years; in 2017 the catch of 34,891 tonnes was far above the limit of 25,000 tonnes. The eastern Atlantic stock, it says, collapsed by around 60% in 12 years; only in the western Atlantic is the trend pointing upwards. Minimum sizes, bag limits and release rules are set by each country — check them locally.

Seven contradictions, left open

One species or two? FishBase contradicts itself: on the page of the Indo-Pacific one it follows Nakamura (1990) and lists two species; on the page of the Atlantic one it says that, according to Eschmeyer’s Catalog of Fishes (following Collette 2006), this one is a synonym — though “several authors” consider it a separate species. GBIF lists both as accepted species, the IUCN only one. The English Wikipedia: no differences were found in the genome (mtDNA), in body measurements or in meristic characters, and most experts see one species. The Russian one: the two have been merged. The German one: increasingly one.
How fast? See above: 109, 110, 111, 119 and 125 km/h in the older figures, 90 km/h in the Italian Wikipedia, 100 km/h in the Russian and the Japanese one — against 36, 35 to 55 and 25 km/h in newer measurements and around 2 km/h on average according to the Japanese Wikipedia. The Spanish one calls it the second-fastest inhabitant of the oceans, behind the black marlin.
Warm or cold water? The English Wikipedia writes that sailfish live in the colder open waters of all oceans. FishBase calls it subtropical and puts the Atlantic one at 21 to 28 °C, as does the German Wikipedia; the Russian one names tropical, subtropical and temperate waters.
Vertical or horizontal stripes? FishBase: about 20 bluish vertical stripes, the French Wikipedia likewise vertical. The German one: about 20 longitudinal stripes of light blue dots. The English page on the Atlantic sailfish: about twenty horizontal stripes.
How big, how heavy? FishBase: 348 cm and 100.2 kg (Indo-Pacific), 315 cm and 58.1 kg (Atlantic) — at 64.6 kg, the Atlantic record from Angola reported by the French Wikipedia lies above that. The German Wikipedia gives 3.80 m as the maximum length, the Japanese one 3.3 m and 20 to 100 kg, the Russian one 3.5 m and around 100 kg, the English one rarely over 90 kg and usually not over 3 m, the Finnish one 45 to 55 kg for adult fish. And the Spanish one writes that in 1963 sailfish caught weighed 120 kg on average — more than any maximum weight at FishBase.
How fast does it grow, how old does it get? In the first year 1.2 to 1.5 m (the English Wikipedia) or 1.5 to 2 m (the Russian one) — or 1 m at two years (the French one). On age: FishBase 13 years for the Indo-Pacific one, but only 4 years for the Atlantic one, as does the Italian Wikipedia. The French one gives 7 years off Florida, 11 (males) and 12 (females) off Taiwan and 13 as life expectancy, the Japanese one 4 to 10, the Russian one 13 to 15 years.
Loner or pack hunter? The Japanese Wikipedia: alone or in small groups of a few fish. FishBase: schools of 3 to 30 individuals or loose aggregations over wide areas. The German one: hunting groups of up to 70 animals — but according to the English Wikipedia, 70 is the result of a mathematical model of the group size up to which hunting together pays off, not a count. And the hunting success: according to the English Wikipedia 24% of attacks, according to the German one one in five.

Five names that lead to the wrong fish

“Espadon voilier”. In French, according to the French Wikipedia and GBIF, it is also called espadon-voilier, “sail swordfish”. But an espadon is the swordfish, *Xiphias gladius* — a different family, with a flat, sharp-edged sword and no pelvic fins at all (the German Wikipedia). This series devotes a separate group to it.
“Marlin”. The Arabic Wikipedia calls it مرلين شراعي, “sail marlin”, the Spanish page on the Atlantic one writes that it is known as a marlin, and the Italian one calls it “a marlin”. It does indeed belong to the marlin family (Istiophoridae); according to the German Wikipedia it is even the sister group of the blue marlin. But the genus is a separate one, *Istiophorus* — and the Spanish Wikipedia itself warns not to confuse the genera *Istiophorus*, *Makaira* and *Tetrapturus*.
The “Pacific” one in the Mediterranean. The Spanish, Italian and Dutch Wikipedia call *I. platypterus* the sailfish of the Pacific (pez vela del Pacífico, pesce vela del Pacifico, Pacifische zeilvis); in Danish, GBIF lists only “Pacifisk sejlfisk”. Yet it is precisely this “Pacific” one that, according to FishBase, enters the Mediterranean via the Suez Canal. And in its very first sentence the Italian Wikipedia also calls it “pesce vela atlantico” — the name of the other species.
“Agulhão”, “Парусник”, “purjemarliini”. In Portuguese, GBIF lists it as Agulhão and Agulhão-bandeira, the Portuguese Wikipedia as agulhão-vela — but agulhão is also used for the blue marlin (GBIF: agulhão-negro); the only unambiguous name is peixe-vela. The Russian Парусник also means sailing ship, which is why the Russian Wikipedia titles its article “Парусник (рыба)”. And the Finnish purjemarliini, “sail marlin”, is given by GBIF not to it but to the blue marlin; in Finnish, the sailfish is purjekala.
Many names in Japan — and several in English. The Japanese Wikipedia lists many local names, among them ビョウブサシ (Toyama, Ishikawa), ミノカジキ (Kanagawa) and アキタロウ, “autumn Tarō”, in Kagoshima — because there it is caught mainly in autumn. And in English? GBIF lists Sailfish, Atlantic sailfish, Indo-Pacific sailfish, Pacific sailfish and Bayonet-fish. In German, GBIF lists only Fächerfisch and Indopazifischer Fächerfisch; the German Wikipedia calls it Fächerfisch, “often also Segelfisch”, and the second species Atlantischer Fächerfisch. The Mediterranean spearfish, the only marlin that spends its whole life in the Mediterranean, and the blue marlin are covered by separate groups in this series.

That leaves the question every article in this series starts with: when. Depth, prey and hunting style are covered above, and they are fixed. What changes every day is everything else — and that is exactly where it is decided whether a day on the water is worth it. That is what StrikeAhead calculates: it takes the conditions on your water and tells you when the trip is worth it. And because you can’t read warm coastal water and the schools in it from day one, StrikeAhead Pathfinder tells you who to go out with: curated guides and skippers, personally vetted before listing — licence and insurance —, with verified catches instead of promo photos, no paid ranking and, for you as an angler, no booking fee.

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