Dictionary:

sailfish

  (sāl'fĭsh')

Any of various large marine fishes of the genus Istiophorus, having a large saillike dorsal fin and an upper jaw that is prolonged into a spearlike bone.

Istiophorus platypterus

FAMILY

Istiophoridae

TAXONOMY

Istiophorus platypterus (Shaw, 1792), Indian Ocean. Some authors, such as Nakamura (1985), differentiate the Atlantic sailfish, I. albicans (Latreille, 1804), as a separate species.

OTHER COMMON NAMES

French: Voilier; Spanish: Pez vela.

PHYSICAL CHARACTERISTICS

Sailfishes reach a maximum size of approximately 11 ft (3.5 m) total length and 220 lb (100 kg). Body fairly compressed. Two dorsal and two anal fins, the first dorsal fin sail-like and remarkably higher than greatest body depth, with 42–49 rays. Second dorsal fin with six or seven rays, slightly posterior to second anal fin which also has six or seven rays. Pectoral fins moderate, 18–20 rays. Pelvic fins extremely long, almost reaching the anus, depressable into a groove, with one spine and several rays tightly fused together. Jaws and palatine bones with small, file-like teeth. Gill rakers absent. Left and right branchiostegal membranes broadly united. Vertebrae, 24. Swim bladder made up of many small bubble-shaped chambers.

DISTRIBUTION

Most researchers consider the sailfish to be a single pantropical species occurring in all three major oceans.

HABITAT

An epipelagic and oceanic species, usually found above the thermocline. Sailfishes have a strong tendency to approach continental coasts, islands, and reefs.

BEHAVIOR

Sailfishes occasionally form schools or smaller groups of 3–30 individuals, but more often occur in loose aggregations over a wide area.

FEEDING ECOLOGY AND DIET

Feeding behavior has been observed by fishermen: One or several sailfish locate a school of prey fish (such as sardines, anchovies, mackerel, or jack mackerel) and pursue the school at half speed with their fins half-folded back into the grooves. They then drive at the prey at full speed with fins completely folded back and make sharp turns with fins expanded to confront part of the school and strike the prey with their bills. They feed on the killed or stunned fish, usually head first as well as on a variety of fishes, crustaceans, and squid.

REPRODUCTIVE BIOLOGY

Spawning occurs with males and females swimming in pairs or with two or three males chasing one female. Sailfishes spawn throughout the year in tropical and subtropical waters with peak spawning in local summer seasons. Ripe ovarian eggs are approximately 0.03 in (0.85 mm) in diameter and have a single oil globule. Eggs shed from a captured female averaged 0.05 in (1.30 mm) in diameter.

CONSERVATION STATUS

Not threatened.

SIGNIFICANCE TO HUMANS

Sailfishes are often taken as bycatch by the commercial surface tuna long liners. United Nations Food and Agriculture Organization (FAO) catch statistics for 1991–2000 show catches of 11.1–23.7 thousand tons (10.1–21.5 thousand metric tons) per year by 42 countries. Sailfishes are primarily important as a sportsfish taken by trolling at the surface. The all-tackle gamefish record is a 221-lb (100.2-kg) fish taken off Santa Cruz Island, Ecuador.

(click to enlarge)
Sailfish (Istiophorus platypterus) (credit: D. Corson — Shostal)

Valued food and game fish in the genus Istiophorus (family Istiophoridae) of warm and temperate waters worldwide. It has a long, rounded spear extending from its snout but is distinguished from marlins and related species by its slimmer form, long pelvic fins, and especially its large, sail-like dorsal fin, which is bright blue and spotted. Deep blue above and silvery below, they grow to about 11 ft (3.4 m) long and 200 lbs (90 kg) or more. They feed mainly on other fishes. Its classification is uncertain, and one (I. platypterus) to several species may be recognized.

For more information on sailfish, visit Britannica.com.

This article is about the fish. For other meanings see Sunfish (dinghy) and USS Sailfish.

Sailfishes
Indo-Pacific sailfish, Istiophorus platypterus
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Actinopterygii Order: Perciformes Family: Istiophoridae Genus: Istiophorus Lacépède, 1801
Species
Istiophorus albicans Istiophorus platypterus

Sailfishes (genus Istiophorus) are fish living in all the oceans of the world. They are blue to gray in color and have a characteristic sail (dorsal fin) on top, which often stretches the entire length of the back. Another notable characteristic is the elongated bill, resembling that of a swordfish.

All sailfish species grow quickly, reaching 1.2 to 1.5 meters in length in a single year, and feed on the surface or at mid-depths on smaller pelagic fishes and squid. Individuals have been clocked at speeds of up to 68.5 mph, making them the fastest fish in the ocean. Generally, sailfish do not grow to more than 10 feet in length and rarely weigh over 200 pounds, although larger specimens have been seen off the shores of Costa Rica.

The sail is normally kept folded down and to the side when swimming, but it may be raised when the sailfish feels threatened or excited, making it appear much larger than it actually is. This tactic has also been observed during feeding, when a group of sailfish use their sails to "herd" a school of fish or squid.

Sailfish are highly prized game fish and are known for their incredible jumps.

Species

• Atlantic sailfish, Istiophorus albicans.
• Indo-Pacific sailfish, Istiophorus platypterus.

External links

• Sailfish Pictures

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