Many species of small fish will jump out of the water in an attempt to evade predators, but the fifty or so species of Flying Fish have perfected the art. They all have very large fins, and when airborne they spread them rather like the wings of a bird. They glide rather than fly, but since they flap their ‘wings’ about it looks very much like bird flight. ‘Flights’ can last as much as 45 seconds (see video of a record flight) and cover significant distances.
Changing Medium to Escape Predators
If a bird is being hunted by a flying predator it will often try to reach the ground – if hunted on the ground it will fly away. Some land animals jump into water when they are attacked, and this might explain why the ancestors of the whales originally took to the water). All Flying Fish feed on plankton near the surface, and their predators (Swordfish and Tuna in the main) come at them from below. Simply leaping up into the air would not be much use since they would be gobbled up as soon as they fell back in, but the ability to glide many metres away is obviously very useful.
Flying Fish Eyes and Vision
All Flying Fish have large eyes, which is not surprising since they find their food by looking for it in the very clear water. But their eyes are also rather less spherical than those of most fish, and this probably allows them to see quite well when they are airborne. As they fall back towards the surface they are able to orientate themselves so that the back end dips in first, and a few powerful strokes with the tail and hind fins kicks them back up into the air. Clear vision is obviously needed to get each ‘landing’ right, since the surface of the water is rarely static and being able to choose a suitable ‘landing’ site is essential.
Feeding on Plankton
Planktonic animals such as copepods feed directly on highly nutritious plant plankton. Fish that can feed directly on the small animal plankton will themselves be highly nutritious, and Flying Fish are supposed to taste very good indeed! Not only is feeding directly on plankton very healthy, it is also extremely efficient (as is demonstrated by the way that Krill feed Huge Whales).
Hieronymus Bosch
There are many beautiful paintings of different Flying Fish, and one of the amusing ones precedes this article. Hieronymus Bosch (Jeroen Anthonissen van Aken) had heard of flying fish, but he either imagined they were much larger than they are – or simply indulged his imagination!
