Tuesday, July 27, 2010
July 27, 2010 : Flying Fish
Exocoetidae, is a family of marine fish in the order Beloniformes of class Actinopterygii. Fishes of this family are known as flying fish. They comprise about 64 species grouped in seven to nine genera.
Flying fish live in all of the oceans, particularly in warm tropical and subtropical waters. Their most striking feature is their pectoral fins, which are unusually large, and enable the fish to hide and escape from predators by leaping out of the water, taking short gliding flights through air just above the water's surface. Their glides are typically around 50 metres (160 ft).
In order to glide upward out of the water, a flying fish moves its tail up to 70 times per second. It then spreads its pectoral fins and tilts them slightly upward to provide lift.
At the end of a glide, it folds its pectoral fins to reenter the sea or drops its tail into the water to push against the water to lift itself for another glide, possibly changing direction.
The curved profile of the "wing" has an aerodynamic shape that is comparable to that of a bird wing. The fish is able to increase its time in the air by flying straight into or at an angle to the direction of updrafts created by a combination of air and ocean currents.
Genus Exocoetus has one pair of fins and a streamlined body to optimize for speed, while Cypselurus has a flattened body and two pairs of fins which maximizes its time in the air.
Flying fish can use updrafts at the leading edge of waves to cover distances of at least 400 m (1,300 ft). They can travel at speeds of more than 70 kilometres per hour (43 mph). Maximum altitude is 6 m (20 ft) above the surface of the sea. Some accounts have them landing on ships' decks.