Indo-Pacific Sailfish (Istiophorus platypterus)
It is believed that the sailfish’s dorsal fins are used in temperature regulation. Their ‘sails’ have a large network of blood vessels, and are often raised at or near surface waters before or after high speed bursts. Sailfish have been known to travel up to speeds of 109 km/h (68mph).
(via moreanimalia)
Source: ichthyologist












