Flying fish are remarkable marine animals with an extraordinary ability to launch themselves from the water and glide through the air. This aerial behavior is a unique adaptation in the marine world. This article explores their characteristics, glide mechanics, and evolutionary reasons for aerial movements.
What Are Flying Fish?
Flying fish belong to the family Exocoetidae, a group of ray-finned fish comprising around 40 to 60 species. They are characterized by their streamlined, torpedo-shaped bodies, which reduce drag both in water and air. A distinctive feature is their unusually large, wing-like pectoral fins, and some species also possess enlarged pelvic fins, giving them a “four-winged” appearance.
These fish are found globally in warm tropical and subtropical ocean waters, including the Atlantic, Pacific, and Indian Oceans. While their name suggests flight, they do not flap their fins like birds. Instead, their aerial movement is a powerful, sustained glide above the water’s surface. They typically range in length from about 6 to 18 inches.
How Flying Fish “Fly”
The process of a flying fish’s glide begins underwater, where the fish builds considerable speed. They propel themselves rapidly toward the surface, often reaching speeds exceeding 35 miles per hour. As they break the water’s surface, they extend their large pectoral fins, which act as airfoils.
The lower lobe of their deeply forked caudal (tail) fin remains submerged, rapidly sculling against the water for additional thrust and lift, much like a propeller. This action allows the fish to become fully airborne. Once completely out of the water, the tail is lifted, and the fish glides on its rigid fins. Glides typically cover distances of up to 650 feet, but some can extend over 1,300 feet, particularly when aided by updrafts from ocean waves. They can reach heights of up to 20 feet above the surface.
The Purpose of Their Aerial Escapades
The primary reason flying fish launch themselves into the air is to evade predators. This aerial escape allows them to quickly flee from fast-swimming underwater threats such as dolphins, tuna, marlin, and swordfish. By breaching the surface and gliding, they can momentarily disappear from the sight of aquatic pursuers, potentially confusing them.
While effective against underwater predators, this strategy introduces a different risk: exposure to avian predators. Birds like frigatebirds and gulls can prey on flying fish during their time above the water. This trade-off highlights an evolutionary adaptation for survival in a complex marine ecosystem.