The shortfin mako is believed to be the fastest-swimming of all shark, thought to be capable of attaining bursts of speed of up to 35 kilometres per hour, and famed for making spectacular leaps of up to six metres out of the water. The species’ high tail produces maximum thrust to propel the shark rapidly forward, both in extreme bursts of speed, and for sustained, long-distance travel. The shortfin mako also has a heat exchange circulatory system that enables the body to be warmer than surrounding water, and thus maintain a high level of activity. This large, stream-lined shark has a distinctively crescent-shaped caudal fin, a long, conical snout, large black eyes and razor-sharp, blade-like teeth. The upper body is a brilliant metallic blue, while the underside is snow-white, with older, larger specimens tending to be darker with reduced white areas. Juveniles are therefore generally paler than adults, and also differ by possessing a clear black mark on the tip of their snout. The shortfin mako can be distinguished from the only other mako shark, the longfin mako (Isurus paucus), not only by having shorter pectoral fins, but also by the white colouration on the underside of the snout and around the mouth, which is darkly pigmented in the longfin mako.