Indo-Pacific sailfish

Istiophorus platypterus

The Indo-Pacific sailfish (Istiophorus platypterus) is a billfish reaching up to 3.4 m, famous for its enormous retractable dorsal fin that resembles a sail. The fastest fish in the ocean, it can reach speeds over 110 km/h. Its body is dark blue above fading to silver-white below, with about 20 vertical bars of pale blue spots. The sail is cobalt blue with dark spots. It hunts cooperatively, using its sail to herd schools of baitfish like sardines into tight balls before slashing through them with its bill. Divers occasionally encounter them during organized sailfish encounters off Mexico, Mozambique, and other locations. Witnessing a sailfish hunt is considered one of the ultimate marine wildlife experiences.