There’s something about sailfish that is just really cool. They look so streamlined and well-adapted to life in the sea that I can’t help but like them. Also that nose! So cool.
The Indo-Pacific sailfish lives in the Indian and Pacific oceans, generally staying in tropical regions. They prefer to stay in the higher, sunlit level of the ocean known as the epipelagic zone. In these waters, temperatures tend to be fairly warm, which is nice for the sailfish, as they like temperatures of between 25 to 30 degrees celsius.
The sailfish is built for speed: they are narrow and extremely streamlined. They grow up to 3.4 meters, with some specimens weighing 100 kilograms. Indo-Pacific sailfish have a form of countershading, where they are dark on top but light on the bottom, to camouflage in the ocean. Their top jaw is modified into a spear-like projection, and they have a huge dorsal fin which gives the sailfish its name. As sailfish grow, their scale size decreases until scales are pretty much absent in adults.
All of the sailfish’s adaptations make it a speed demon – it has been measured swimming at 110 km/hr. When they are swimming they can fold down their ‘sail’ to reduce drag. The fish also may use their sail to thermoregulate, as they raise their sail above water before high-speed sprints.
The sailfish’s speed allows it to go after faster prey than most ocean hunters can. Some of the sailfish’s prey include tuna, mackerel, sardines and anchovies. When hunting, the sailfish use their bill to hit their prey, sunning or killing it. I definitely wouldn’t want to be the prey of a 100 kg fish with a pointy nose that can travel over 100 km/hr.
Indo-Pacific sailfish are often caught as bycatch by tuna fishers, and are also a highly prized sport fish. Sailfish is also used in sushi and sashimi in Japan. These fishing pressures likely have had a serious impact on the sailfish population, but data is insufficient to truly assess the state of sailfish fisheries. Hopefully sometime soon we can change this, and protect sailfish before things get out of hand. I would be very sad if sailfish went extinct.
Cover image source: http://fishidentificationblog.blogspot.ca/2012/12/sailfishatlantic-sailfishindo-pacific.html