The fastest land animal is the cheetah, which has a recorded speed of between 109.4 km/h (68.0 mph) and 120.7 km/h (75.0 mph). The peregrine falcon is the fastest bird, and the fastest member of the animal kingdom, with a diving speed of 389 km/h (242 mph). The fastest animal in the sea is the black marlin, with a recorded speed of 129 km/h (80 mph).
When drawing comparisons between different classes of animals, an alternative unit is used for organisms: body length per second. The fastest organism on earth, relative to its body length, is the South Californian mite, Paratarsotomus macropalpis, which has a speed of 322 body lengths per second.
The equivalent speed for a human, running as fast as this mite, would be 1,300 mph (2,092 km/h) The speed of the Paratarsotomus macropalpis is far more than the previous record-holder, the Australian tiger beetle, Cicindela eburneola, which is the fastest insect in the world relative to body size, with a recorded speed of 1.86 meters per second (6.7 km/h; 4.2 mph), or 171 body lengths per second. The cheetah, the fastest land mammal, scores at only 16 body lengths per second, while Anna's hummingbird has the highest known length-specific velocity attained by any vertebrate.