London, June 21 (ANI): US researchers have partly been successful in solving the mystery behind the speed and agility of dolphins and porpoises.
They believe the secret can be explained by the mammals' ability to deploy flippers in the same "delta wing" pattern as jet fighters.
Boffins have found that the sea mammals use swept-back design to generate lift while minimising drag from the water - a similar mechanism to that used by aircraft.
Tiny twists to the flippers can also generate sharp changes in direction - the key to agility, reports The Times.
The finding may come handy in explaining how they are able to reach extraordinary speeds, such as the 20mph achieved by the striped dolphin.
Theoretically speaking, such speeds in water should produce so much friction that the creature should never be able to sustain them - or so researchers have thought.
However, Frank Fish from West Chester University, Pennsylvania, worked with the US Naval Academy and other researchers to build up exact profiles of the flippers of seven species, from the Amazon river dolphin and pygmy sperm whale to the striped dolphin.
To reach the conclusion, the shapes were analysed with computerised tomography of real flippers, and the researchers built exact scale models for testing in a water tunnel, they told a meeting of the American Physical Society.
"We found that swept-back flippers generate lift like modern delta-wing aircraft," said Fish. (ANI)