Article Flying Hatchets

FLYING HATCHETS

The aerodynamic shape of hatchetfish, with the deep, boatlike keel, means that these fish are sufficiently streamlined to be able to leap out of the water without difficulty.

Their flat topline reflects the fact that hatchetfish normally lurk just below the surface, grabbing surface-swimming invertebrates and others that touch down momentarily on the water.

The upturned mouth is another adaptation to surface feeding.

When hatchetfish are viewed from above, their flat body shape makes them difficult to spot, even near the surface, because so little of the body is visible.

They have sharp eyesight to help them catch prey and avoid predators.

On occasion, usually to escape would-be predators approaching them in the water, these fish will take to air.

The flapping movements of their pectoral fins are powerful enough to keep them airborne, enabling them to cover distances of up to 4' before reentering the water.

While in the air, they use their caudal fin to provide them with some directional guidance.

It is essential that an aquarium housing hatchetfish is kept covered, even when it is being serviced, because otherwise they are likely to leap out into the room.