a family of marine fishes, Exocoetidae, with about 52 species in tropical to warm-temperate oceans. They do not fly but glide for long distances out of the water using greatly expanded pectoral, pelvic and caudal fins, the expansion varying between species (fish with enlarged pectoral fins are called monoplane or two-winged, those with enlarged pelvics also are called biplane or four-winged; the former are more erratic fliers). The flight occurs after a build up of speed under water, aided by the enlarged lower lobe of the caudal fin, when the fish breaks out of the water or a wave front, sometimes gliding high enough to land on ships. Free flights last 13 seconds or more and touch-and-go flights 42 seconds or more. Air speeds reach 55 km/h and cover up to 200 m
Dictionary of ichthyology. 2009.