The Indo-Pacific sailfish (Istiophorus platypterus) is one of the world’s most charismatic fish species.
In my opinion the sailfish is one of the best sport fish to catch as they are not small, not overly huge, powerful, offers spectacular aerial acrobats when hooked, grows quickly, spawns year-round, often hunts in schools, found along coastal waters and they look incredible with that sail.
They can display spectacular coloration when feeding or ‘excited’ which is termed as ‘lit-up’. Their colours can also be dark brown/bronze-black. 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.
There are two main subspecies of sailfish, Atlantic and Indo-Pacific. The larger of the two, the Indo-Pacific sailfish is what we catch at Kuala Rompin.
What is the sail-like dorsal fin for?
The sailfish uses its sail for various purposes. I have observed many sailfish and the sail is folded down when swimming fast and erected when hunting or herding bait fish. The sail also makes the sailfish appear much bigger than they are.
I have also observed sailfish making almost instantaneous stop when they suddenly erect its sail suggesting it helps them manoeuvre better in the water.
Although I personally doubt this, it is theorised that the sail-like dorsal fin may also serve the purpose of a cooling and heating system due to a large number of blood vessels found in the sail and because of “sail-raising” behaviour exhibited by the sailfish at or near the surface waters after or before high-speed bursts.
The fastest fish in the ocean.
Sometime ago someone apparently recorded the burst speed of sailfish clocking speeds of 110 km/h (68 mph). That’s like 100 meters in 5 seconds! Hence the claim of sailfish being among the fastest fish in the ocean. Or anywhere with water. Although more conservative speeds of 40km/h to 55km/h are more commonly accepted.
How big do sailfish get?
Sailfish grows quickly in the first year reaching 1.2-1.5 metres (4-5 feet) in length.
The claimed maximum size and weight of a sailfish are 340cm (11 feet) and 100kg (220 pounds). It is rare to see sailfish more than 3 metres (9 feet) and above 90kg (200 pounds).
Sailfish caught in Kuala Rompin commonly weigh around 20kg and measures around 120cm to 180cm (4 to 6 feet) in length.
A 10 year old fish is considered very matured and the oldest recorded is 13 years old.
The Indo-Pacific sailfish generally feed on the surface or at mid-depths takes a variety of food items, including fish, crustaceans and cephalopods, but its most common source of prey is schooling fishes, such as sardines, anchovies and mackerel.
I have personally witnessed sailfish regurgitate out the above fish species during a fight.
When feeding upon schooling fish, the Indo-Pacific sailfish herds the shoal into a dense group called a ‘bait ball’ before swimming through and making slashing movements with their bill. The resulting impact with the sailfish’s bill kills or stuns large number of fish, which are then picked off as they sink through the water column.
The Indo-Pacific sailfish’s reproductive behaviour involves the male and female swimming in pairs, or several males chasing a single female, prior to spawning taking place. The female produces huge numbers of eggs, which hatch into tiny larvae, and develop the sail-like dorsal fin and elongated bill when only five centimetres long.
Threats to the Rompin sailfish
Although not targeted as food fish, every year hundreds of tons of sailfish gets caught in commercial fishing nets as bycatch resulting in huge amount of loss to the sport fishing industry that contributes to the tourism economy.
Many dead sailfish are dumped back into the ocean and those brought back to shore are sold for peanuts as feeds and to make crackers when every single fish can contribute tens of thousand of dollars to the local economy.
If you have any questions about Rompin sailfish fishing, write to us and we will be happy to help you.
Find out more about conservation of the Indo-Pacific sailfish and other billfish species:
The Billfish Foundation:
IUCN Red List draft assessments (July, 2011)
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 Fisheries Synopsis, 125: 1 – 65.
FishBase (September, 2009)
Burton, M. and Burton, R. (2002) International Wildlife Encyclopedia. Marshall Cavendish, New York.
Australian Museum (September, 2009)
The Billfish Foundation (September, 2009)