Sailfin Flyingfish

The Sailfin Flyingfish (Parexocoetus brachypterus) belongs to the flyingfish family Exocoetidae and is one of the smaller, more coastally distributed members of the group. Unlike many of its relatives, it is a "two-winged" flyingfish, possessing only enlarged pectoral fins rather than both pectoral and pelvic "wings." Its most distinctive feature is a tall, dark, sail-like dorsal fin, which gives the species its common name. Sailfin Flyingfish occur in subtropical and tropical coastal and sub-coastal waters across the Atlantic, Indian, and Pacific Oceans, from roughly 37°N to 35°S. It is a common surface species around continental shelves and islands, gliding above waves to avoid fast predatory fish, and reaches lengths of about 16-20 cm as an adult.

• Small, blunt-snouted flyingfish reaching about 12-20 cm in length
• Distinctive tall, dark, sail-like dorsal fin, taller than in most other flyingfish species
• Only the pectoral fins are enlarged into "wings"; pelvic fins remain short, unlike four-winged flyingfish
• Blue-grey back grading to silvery sides and belly
• Grey pectoral fins, generally unmarked or faintly banded, shorter than those of many open-ocean flyingfish species
• Deeply forked tail with an elongated lower lobe used to build speed before gliding
• Best distinguished from other flyingfish by the combination of a blunt snout and oversized dorsal sail

Sailfin Flyingfish live at the ocean surface in warm coastal and sub-coastal waters rather than the deep open ocean favored by some relatives. Its range spans subtropical and tropical latitudes roughly between 37°N and 35°S across the Atlantic, Indian, and Pacific Oceans, including the Caribbean Sea, Lesser Antilles, and waters off West Africa and the Indo-Pacific. It is commonly encountered over continental shelves, around islands, and in waters influenced by warm currents, staying within the upper few meters where light and temperature support its planktonic food supply. It generally avoids cooler upwelling zones and the deeper offshore waters used by some other flyingfish species.

Sailfin Flyingfish form loose surface schools and use the same gliding escape strategy as other Exocoetidae: rapid sculling of the elongated lower tail lobe propels the fish to speeds sufficient to break the surface, after which the pectoral "wings" and tall dorsal sail stabilize a long glide over the waves. Glides of roughly 50 to 400 meters have been recorded, with the fish reaching estimated speeds up to 70 km/h before launch. This behavior primarily evades predatory fish hunting from below. The species feeds on small planktonic organisms near the surface and spawns in open water, releasing eggs with adhesive filaments that catch on floating weed or debris rather than settling on the seafloor.