J. Exp. Biol. 213, 3269–3279 (2010)

Flying fish are well adapted for gliding through both water and air, staying airborne (pictured) for distances of up to 400 metres. To assess the aerodynamics of these creatures, Hyungmin Park and Haecheon Choi at Seoul National University stuffed five darkedged-wing flying fish (Cypselurus hiraii) that they had caught in the Sea of Japan. They placed the fish in a wind tunnel at different angles and with their fins in different positions, and measured the flow of air around them.

The analysis showed that the arrangement of the fins accelerates the flow towards the tail in the same way as the wings of a jet, providing extra lift and allowing the remarkable fish to fly for more than 30 seconds. Measurements of the lift-to-drag ratio revealed that the fish can fly furthest when close to, and parallel to, the surface of the water.

Credit: T. STACK/PHOTOLIBRARY