Deep-sea Dragonfish Use a Bioluminescent Lure to Entice Prey

The dragonfish is a small but terrifying predator, growing up to 15 inches (38 cm) in length. Its body is long and slender, with dark, almost black coloration to help it blend into the inky darkness of the deep sea. They also have large heads and sharp, fang-like teeth that can easily pierce through their prey.

One of the most striking features of the dragonfish is its bioluminescent organs, known as photophores, which are scattered along its body. Bioluminescence refers to an animal's ability to produce its own light.

When you combine that with a dragonfish jaw full of knife-like teeth, you'd be hard-pressed to hold your own as its prey.

They have a glowing lure beneath their chin, which they use to attract prey. Needless to say, the ability to produce light to lure and detect prey is one of the most advanced adaptations in the animal kingdom.

There are two prominent dragonfish species, each with unique traits. The most famous is the black dragonfish (Idiacanthus atlanticus), which emits red light from its pitch dark body. It's the same aesthetic you'd see behind the Terminator's sunglasses when he's angry.

The scaleless dragonfish (Bathophilus flemingi) are even stranger-looking; without scales, they start to look less like fish and even more like monsters. All species come from the family Stomiidae, which contains many species of undersea swimmers beyond the dragonfish.

These species of dragonfish are distributed across the world's oceans, with some species found in the Atlantic, Pacific and Indian Oceans. Despite their differences, all dragonfish share the same predatory lifestyle and incredible adaptations for the deep sea.

Dragonfish are solitary hunters, spending most of their lives alone in the vastness of the ocean. They are ambush predators, using their blue bioluminescence to attract prey. When their prey gets close enough, they strike with lightning speed, swallowing it whole.

Because dragonfish are so spread out in the deep sea, interactions between individuals are rare. During the breeding season, however, males and females may come together to spawn, ensuring the continuation of their species.

The life cycle of a dragonfish begins as a larva floating all the way near the surface of the ocean. As a larva, the fish looks very different from its adult form, with a transparent body and long, trailing fins.

Over time, the larva descends miles and miles down into the deep sea, undergoing metamorphosis to become an adult.

As adults, dragonfish continue to grow and develop their bioluminescent organs. Females are typically larger than males, and in some species, males lose the ability to feed after reaching maturity, surviving only long enough to reproduce.

Dragonfish are carnivores, feeding on smaller fish, crustaceans and other deep-sea creatures.

Their prey is often drawn to the glowing lure beneath the dragonfish's chin, which acts as a beacon in the dark. Once their prey is close, the dragonfish uses its sharp teeth to capture and consume it.

Dragonfish are opportunistic feeders, meaning they will eat whatever they can find. This feeding strategy is essential in the deep oceans, where food can be scarce.

Dragonfish are found in the midnight zone, a region of the ocean that lies between 3,300 and 13,000 feet (1,000 and 4,000 meters) below the surface. This part of the ocean is pitch black, cold and under immense pressure, making it one of the most extreme environments on Earth.

But none of that is a problem for these ferocious fish! Their dark coloration helps them avoid detection, and their bioluminescence paves the way for them to navigate and hunt.

Some species can even migrate vertically, rising closer to the surface at night to find food and returning to the depths during the day.

Dragonfish are not currently considered endangered, but their deep-sea habitats face increasing threats from human activity.

Deep-sea mining, pollution and climate change could disrupt the delicate ecosystems where these fish live. Despite their resilience, dragonfish populations could be affected if their environment becomes less stable.

Scientists continue to study dragonfish and other deep-sea species to understand their role in the ocean's ecosystem. Protecting the midnight zone is critical to ensuring the survival of these extraordinary creatures and the balance of life in the ocean.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.