Flyingfish

"Flyingfish" is the common name for about 70 species in the family Exocoetidae, part of the order Beloniformes. This entry uses the Flyingfish (Exocoetus volitans) as a representative species, one of the most widely distributed members of the family. Flyingfish are best known for their ability to glide above the ocean surface using greatly enlarged pectoral fins, sometimes aided by enlarged pelvic fins in "four-winged" species. They inhabit warm, open surface waters of the Atlantic, Indian, and Pacific Oceans, generally far from shore over deep water. Flyingfish are an important prey species for tuna, dolphinfish, billfish, and seabirds, and their gliding flight is a defining evolutionary adaptation for escaping fast underwater predators.

• Streamlined, torpedo-shaped body, generally 20-30 cm long as adults for common species
• Greatly enlarged, wing-like pectoral fins, reaching past the dorsal fin origin and used for gliding
• Deeply forked tail with a much longer lower lobe, used to build speed before takeoff
• Dark blue-black to iridescent back, sharply demarcated from a silvery-white belly
• Some species ("four-winged" flyingfish) also have enlarged pelvic fins forming a second pair of "wings"
• Distinguished from needlefish and halfbeaks, which lack enlarged pectoral fins and cannot glide, by the size and shape of the pectoral fins alone

Flyingfish live at the very surface of warm, open tropical and subtropical seas across the Atlantic, Indian, and Pacific Oceans, typically far from shore over deep offshore water. They favor sea surface temperatures generally above about 20°C and are strongly associated with major warm currents, which influence their seasonal distribution. Most species remain within the top few meters of the water column throughout their lives, since both their gliding escape behavior and their feeding on surface plankton depend on staying at the air-water interface. Some species occur closer to coasts and continental shelves, while others range widely across open ocean basins, but nearly all avoid cold or deep water.

Flyingfish are schooling, surface-dwelling fish whose signature behavior is gliding flight: an individual builds speed underwater with rapid beats of the elongated lower tail lobe, breaks the surface, and spreads its enlarged pectoral fins (and, in four-winged species, pelvic fins as well) to soar passively over the waves for distances that can exceed one hundred meters. This gliding is primarily an escape response to fast predatory fish such as tuna, dolphinfish, and billfish hunting from below. Flyingfish feed mainly on planktonic organisms near the surface. Spawning occurs in open water, and eggs typically bear sticky filaments that attach to floating sargassum weed or debris, since the family provides no parental care after spawning.