Sailfish are a genus Istiophorus of billfish living in warmer sections of all the oceans of the world. They are predominantly 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.
- 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 oceansaround the world.
- Individuals have been clocked at speeds up to 110 km/h (68 mph), which is one of the highest speeds reliably reported in any water organism.
- 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.
- They can appear in a startling array of colors, from subdued browns and grays to vibrant purples and even silver.
- Sailfish can change their colors 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 signaling its intentions to fellow sailfish.