Hatchetfish
Sternoptyx obscura
- Not on exhibit
- Animal type
- Fishes
- Ecosystem
- Deep sea
- Relatives
- Silver hatchetfish; bottlelight fish
- Diet
- Tiny crustaceans, animal plankton
- Range
- Temperate and tropical seas worldwide, at depths of 1,310 to 4130 feet (399–1,259 meters)
- Size
- Up to 3 inches (8 cm)
Meet the hatchetfish
Hatchetfish are well camouflaged. Like many deep sea fishes, they have light-producing organs in rows along their bellies. These organs shine a pale blue light that matches daylight filtering down from above, and hides them from predators below.
Did you know?
Hatchetfish can regulate the intensity and color of light from these organs to match the light filtering down. Each species of hatchetfish has its own particular pattern of lights.
This use of bioluminescent light is called "counterillumination," a common adaptation in midwater fishes and cephalopods. Some midwater predators hunt by looking up for the silhouettes of animals. Counterillumination makes hatchetfish almost invisible from below.
Conservation
Anything that finds its way into the ocean, whether it's tossed away as trash, washes off a beach or falls off a boat, may eventually make its way to the deep sea. It's important to realize that the deep sea is not so far away that it's beyond the reach of human activities. Living creatures in the deep are affected by what we do at the surface.
Cool fact
- A hatchetfish's eyes can focus close up or far away.
Want to see amazing deep-sea creatures up close?
Visit our exhibition, Into the Deep: Exploring Our Undiscovered Ocean (En lo Profundo: Explorando Nuestro Océano Desconocido).
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