Marine Hatchetfish

deep sea · bioluminescence · tiny fish

Razor-thin body. Marine hatchetfishes are so flat and narrow that they look like swimming blades or tiny hatchets, which is exactly how they got their name.

Eyes point upward. Their big eyes face straight up toward the surface so they can spot prey and predators above them in the dark ocean.

Glowing belly lights. These fish have rows of light-producing organs called photophores running along their sides and belly that they use to talk to other fish and hide from bigger predators.

Super deep home. Marine hatchetfish live in the mesopelagic zone, the twilight area of the ocean between 200 and 1,000 meters down where almost no sunlight reaches.

Teeny tiny fish. Most marine hatchetfish are only about 2 to 6 inches long, making them some of the smallest fish in the entire ocean.