Flying Fish are interesting creatures. And unless you have a really big house you shouldn't have them in your fish tank at home. A flying fish has thin wings BUT it does not actually fly, it just looks that way. It is actually just gliding. However their glides have been recorded at some crazily long distances.
How far can they fly?
Distances of 400m have been recorded. Thats the length of a running track if it was laid out in a straight line. Take a look at the Discovery Channel episode on these amazing creatures - http://dsc.discovery.com/videos/life-flying-fish-fly.html . They mainly feed on plankton and snack occasionally on some of the smaller crustaceans, so the reason they fly is not so they can eat seagulls!