Marine Species: Flying Gurnard

The flying gurnard is big-eyed, bottom-dwelling fish. What surprising feature makes divers seek them out (and explains their name)?

One peculiarity of diving that never gets old — indeed, it’s addicting — is that we can fulfill childhood dreams of flying. Underwater we can soar across deep canyons, buzz over sandy bottoms, or zoom in and out of swim-throughs. For most fish, of course, this power is common, mundane, unremarkable. For most, that is, except bottom-dwelling species which, like their emu and penguin brethren on land, cannot “fly.”

This evolutionary con is particularly stark in the case of the flying gurnard. To include the word “flying” in the name of a fish that, at best, can sort of skip-glide, seems irredeemably mean-spirited, if not cruel.

What is a flying gurnard?

At first glance of a flying gurnard, the word also seems inapt. It is long and teardrop-shaped, sometimes with a long dorsal fin that sticks on its head like a unicorn’s horn. It uses leg-like ventral fins to skate along the bottom, powered by its tail fin. In other words, it does not look at all like a creature that could fly.

When it feels threatened, however — for example, when a colossal, bubble-blowing animal like a scuba diver approaches — it unfurls large, wing-like pectoral fins. These translucent wings extend the lovely, dappled sand-and-white patterns of the fish’s body, morphing to sand-and-electric-blue, similar in color to its eyes, at the edges.

To predators, the flying gurnard suddenly seems triple its size and the confusing coloration and false “eyes” on its outspread fins hide the location of its head. To people, it suddenly looks a lot like an underwater bird in flight.

The “gurnard” part of the name comes from the old French word for “grunt,” the sound made by muscles beating the fish’s swim bladder (essentially, a fish-BCD) when removed from water.

Types of gurnards

The seven species of flying gurnards belong to the family Dactylopteridae, which comes from the Greek “dactyl,” or finger, and “pterygion,” or fin. This name reveals another quirk about the flying gurnard. The front portions of its magnificent pectoral fins are split off and able to move independently. The flying gurnard uses these like hands to sweep away sediment that might be hiding crustaceans and other small fishy treats that form its diet.

If the name Dactylopteridae sounds vaguely familiar, try flipping the two words: Pterodactyl, which uses “ptero,” which is Greek for wing. While having a Latin name similar to a screeching, terrifying avian carnivore’s might make you wary of seeking out a flying gurnard, fear not. Its huge, anime eyes and somehow cuddly demeanor will dispel any apprehension.

Where and how to find them

Flying gurnards live in coastal tropical and temperate waters in almost all recreational marine dive areas. To find one you needn’t go deep. As larvae, they float around in the ocean. As juveniles, they return to the coasts to hide in seagrass and among piles of coral rubble. Adults prefer relatively flat, sandy, rubbly or muddy bottoms in depths starting at 3 feet (1 m).

Size-wise, they range anywhere from 1.5 to 20 inches (4 to 50 cm) long, and up to a few inches wide, not counting outstretched dorsal fins. Luckily for photographers, they’re relatively slow-moving, and tend to stay around the same area for days or longer.

For fish that rely on camouflage as protection, they move around a lot. Thusly, calm, keen-eyed divers will spot them fairly easily. Look for big, bulging eyes and a hornlike dorsal fin that resembles an upside-down rudder.

Flying gurnards live all the way from Nova Scotia to Blue Heron Bridge in Florida along the U.S. eastern seaboard. Divers will also find them along the eastern islands of the Caribbean, all the way south to Argentina. On the eastern side of the Atlantic, they inhabit the coasts from the Channel Islands to Angola, including the Mediterranean Sea. Similar species live throughout the Indo-Pacific region.

Next time you’re on a flat, rubbly dive site, watch for the flying gurnard, doomed to spend its life with wings that don’t fly.