The maximum swimming speed of a fish is somewhat determined by the shape of its body and its tail and by its internal temperature. The cosmopolitan sailfish (Istiophorus platypterus) is considered to be the fastest fish species, at least for short distances, swimming at greater than 60 miles (95 kilometers) per hour. However some American fishermen believe that the bluefin tuna (Thunnus thynnus) is the fastest, but the fastest speed recorded so far is 43.4 miles (69.8 kilometers) per hour. Data is extremely difficult to secure because of the practical difficulties in measuring the speeds. The yellowfin tuna (Thnnus albacares) and the wahoe (Acanthocybium solandri) are also fast, timed at 46.35 miles (74.5 kilometers) per hour and 47.88 miles (77 kilometers) per hour during 10- to 20-second sprints. Flying fish swim at 40+ miles (64+ kilometers) per hour, dolphins at 37 miles (60 kilometers) per hour, trout at 15 miles (24 kilometers) per hour, and blenny at 5 miles (8 kilometers) per hour. Humans can swim 5.19 miles (8.3 kilometers) per hour. (The Handy Science Answer Book, compiled by the Science and Technology department of the Carnegie Library of Pittsburgh)
