Overview
The black dragonfish is a slim, ribbon-like predator with dark skin that soaks up light. It has a long body, a fang-filled mouth, and a glowing barbel, a whisker-like lure, hanging from its chin. In the deep sea it looks every bit like a tiny dragon.
Male and female dragonfish are so different that it is hard to believe they are the same animal. The females are long, toothy hunters with light-making organs, while the males are much smaller, have no working stomach, and live only long enough to help make the next generation.
| Where it lives | Cold, dark open water of the deep sea |
| Range | Southern deep oceans worldwide, in mild and cold zones |
| Adult size | Females about 16 in (40 cm) long, males much smaller |
| Diet | Small fish and crustaceans |
| Lifespan | Not well known |
| Depth or habitat | Deep by day, rising toward shallower water at night, down to about 6,600 ft (2,000 m) |
| Keep at home? | No, it lives in the deep sea |
Its weirdest feature
The black dragonfish can produce red light from organs near its eyes. Almost no other deep-sea animal can see red, so this works like a secret searchlight, letting the dragonfish spot prey without being noticed.
Surviving the dark deep
Its skin is ultra-black, soaking up nearly all the light that hits it, so even its own glow will not give it away to enemies. It also makes its own blue-green light along its body, a form of bioluminescence, to blend in and to signal.
How it hunts
A glowing lure dangles from the female dragonfish's chin like a fishing rod with a light on the end. She waves it to draw curious prey close, then snaps up the meal with her long, sharp, transparent teeth.
Life in the deep sea
Like many deep-sea fish, the dragonfish rises toward shallower water at night to feed, then sinks back down during the day. Its young are strange too, with eyes on long stalks that later shrink back into the head as they grow up.
An amazing fact
The dragonfish's teeth are transparent, which helps hide them from prey, and its skin is so black it reflects less than one percent of light, making it one of the darkest animals ever measured.
Fun facts
- It can make red light that most deep-sea animals cannot see.
- Its skin is ultra-black and soaks up almost all light.
- Females have a glowing lure on their chin to attract prey.
- Its teeth are see-through to help hide them from prey.
- Young dragonfish have eyes on long stalks.
Frequently asked questions
Why can the dragonfish make red light?
Most deep-sea animals cannot see red, so the dragonfish uses red light like a private searchlight to find prey without being spotted.
Why is it so black?
Its ultra-black skin soaks up light so predators cannot see it, and so its own glow does not reflect and give it away.
Are males and females really that different?
Yes. Females are long, toothy hunters, while males are tiny, have no working stomach, and do not hunt.
Can it live in an aquarium?
No. It lives in the deep sea and cannot survive in a home tank.
