Sailfish are fish in the genus Istiophorus, living in warmer sections of all the oceans of the world. They are predominately blue to gray in colour and have a characteristic erectile dorsal fin known as a sail, which often stretches the entire length of the back. Another notable characteristic is the elongated bill, resembling that of the swordfish and other marlins. They are therefore described as billfish in sport fishing circles.

Species

Two sailfish species have traditionally been recognized.^[2][3] No differences have been found in mtDNA, morphometrics or meristics between the two supposed species and most authorities now only recognized a single species, the sailfish (Istiophorus platypterus), found in warmer oceans around the world.^[3][4][5][6]

• Atlantic sailfish (Istiophorus albicans).
• Indo-Pacific sailfish (Istiophorus platypterus).

Description

An Indo-Pacific sailfish exhibiting sail-raising behavior

Sailfish grow quickly, reaching 1.2–1.5 metres (3 ft 10 in–4 ft 10 in) in length in a single year, and feed on the surface or at mid-depths on smaller pelagic forage fish and squid. Individuals have been clocked at speeds of up to 110 kilometres per hour (68 mph), which is one of the highest speeds reliably reported in any water organism.^[3][7] Generally, sailfish do not grow to more than 3 metres (9.8 ft) in length and rarely weigh over 90 kilograms (200 lb).

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 the fish 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.

Ernest Hemingway in Key West, Florida, USA, in the 1940s, with an Atlantic sailfish he had caught

Sailfish are highly prized game fish and are known for their incredible jumps and great speed.They can swim the 100 meter olympic in 4.8 seconds. They can appear in a startling array of colours, from subdued browns and grays to vibrant purples and even silver. Their body colours are often highlighted by stripes of iridescent blue and silver dots. Sailfish can change their colours almost instantly - a change controlled by their nervous system. The sailfish can rapidly turn its body light blue with yellowish stripes when excited, confusing its prey and making capture easier, while signalling its intentions to fellow sailfish.^[8]

Notes

References

• Schultz, Ken (2003) Ken Schultz's Field Guide to Saltwater Fish pp. 162–163, John Wiley & Sons. ISBN 9780471449959.

The Atlantic sailfish, Istiophorus albicans, is a species of marine fish in the family Istiophoridae of the order Perciformes. It is found in the Atlantic Oceans and the Caribbean Sea, except for large areas of the central North Atlantic and the central South Atlantic, from the surface to depths of 200 m. The Atlantic Sailfish is related to the marlin.

Tests in the 1920s estimated that they were capable of short sprints of up to 111 kilometres per hour; however, more conservative estimates of 37 to 55 kilometres per hour are more widely accepted.^[1]

Atlantic sailfish hunt schooling fish, such as sardines, anchovies and mackerel although they also feed on crustaceans and cephalopods.

Description

Ernest Hemingway in Key West, Florida, USA, in the 1940s, with an Atlantic sailfish he had caught

The Atlantic sailfish is a metallic blue fish with a large sail-like dorsal fin, long and pointed bill. It is darker on the upperparts and lighter on the sides (counter-shading), with bluish vertical bars along the flanks; the underparts are silvery white.^{[citation needed]}

Length is up to 3.15 m and the maximum published weight is 58.1 kg.^[2]

References

1. ^ Burton, M. and Burton, R. (2002) International Wildlife Encyclopedia. Marshall Cavendish, New York.
2. ^ Froese, Rainer, and Daniel Pauly, eds. (2006). "Istiophorus albicans" in FishBase. January 2006 version.

• "Istiophorus albicans". Integrated Taxonomic Information System. http://www.itis.gov/servlet/SingleRpt/SingleRpt?search_topic=TSN&search_value=550888. Retrieved 6 June 2006.