Sailfish, Istiophorus platypterus (Shaw & Nodder, 1792)

Introduction

Most sources believe that the fastest species of fish is the Sailfish, Istiophorus platypterus. It has been clocked in excess of 110 km/h (68 mph) over short periods.

Identification

A fairly compressed body with a long bill and jaws with file-like teeth. It is dark blue above, brownish laterally and silvery below. There are about twenty bars on sides of the body that are made up of bright blue spots.

In the early 1900s it was believed that there were many species of sailfishes. Most authorities now agree that there is a single worldwide species however others believe that there is a different species Istiophorus albicans in the Atlantic.

Habitat

The Sailfish is an epipelagic and oceanic species and shows a strong tendency to approach continental coasts, islands and reefs.

Distribution

The species is widely distributed in the tropical and temperate waters of the Pacific and Indian oceans.

The map below shows the Australian distribution of the species based on public sightings and specimens in Australian Museums. Click on the map for detailed information. Source: Atlas of Living Australia.

Feeding and diet

The Sailfish is an oceanic species that feeds on schooling fishes such as sardines, anchovies and mackerels. Nakamura (1985) states that the feeding behaviour of I. platypterus has been observed by fishermen as follows: "when one or several sailfish found a school of prey fishes, they began to pursue it at about half speed with their fins half-folded back into the grooves. They then drove at the prey at full speed with their fins completely folded back and once they had caught up with it, they suddenly made sharp turns with their fins fully expanded to confront a part of the school and then hit the prey with the bill. Subsequently they ate the killed and stunned fish, usually head first."

Predators

Jeff Johnson from the Queensland Museum stated in March 2010 that: "The only group that I have often heard will actively feed on tetraodontids (pufferfishes and relatives) are sailfish & marlin. I have identified Torquigener spp from gut contents of the latter, especially Torquigener altipinnis. They have often been observed 'balling up' toadfishes at the surface for this purpose and there are reports of them sometimes behaving strangely (eg leaping erratically) following these feeding activities..

References

1. Johnson, G.D. & A.C. Gill in Paxton, J.R. & W.N. Eschmeyer (Eds). 1994. Encyclopedia of Fishes. Sydney: New South Wales University Press; San Diego: Academic Press [1995]. Pp. 240.
2. Nakamura, I. 1985. FAO species catalogue. Vol. 5. Billfishes of the world. An annotated and illustrated catalogue of marlins, sailfishes, spearfishes and swordfishes known to date. FAO Fish. Synop. No. 125 (5): i-iv, 1-65.
3. Pepperell, J. 2010. Fishes of the Open Ocean. A natural history & illustrated guide. University of NSW Press. Pp. 266.
4. Springer, V.G. & J.P. Gold. 1989. Sharks in Question: The Smithsonian Answer Book. Smithsonian Institution. Pp. 187