The Fish With Lethal Weapons for Teeth

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What has needle-like teeth so large they don’t fit inside its mouth, a huge gaping jaw that completely engulfs its prey, and lives in the ocean zone where sunlight can’t reach? That would be the mysterious and utterly fascinating Pacific viperfish. This menacing predator uses its long, sharp teeth as a cage to keep small fish and shrimp trapped once they’re inside its mouth.

The video above, filmed by the Monterey Bay Aquarium Research Institute (MBARI), provides an amazingly close view of this odd-looking fish as it swims deep in the ocean. Its range is anywhere from 655 to 5,000 feet deep, which includes the twilight and midnight ocean zones. In these deep zones, the water is cold and the sunlight is very faint to nonexistent. It’s here where some of the strangest creatures on Earth make their home.

Where Does the Pacific Viperfish Live?

With a depth range of 655 to 5,000 feet, the Pacific viperfish (Chauliodus macouni) can be found living in the deep waters of the Pacific Ocean. The ocean is separated into layers with the surface layer (or sunlight zone) reaching down to 660 feet. Beyond the sunlight zone lives the Pacific Viperfish. This is known as the twilight zone, which ranges from 660 feet to 3,300 feet. However, the Pacific viperfish is known to migrate to greater depths of up to 5,000 feet. This is considered the midnight zone, and it spans from 3,300 to 13,100 feet. The only light in the midnight zone comes from the bioluminescent glowing from the creatures themselves.

About the Pacific Viperfish

The Pacific viperfish is one of nine species of viperfish. All of the species have long, needle-like teeth. There is much we don’t know about the viperfish due to the great depths in which they live. Spending their entire lives in the twilight and midnight zones of the ocean means they have had little interference from humans. We aren’t even sure how they reproduce, but scientists believe they spawn externally. This is when the females release eggs which the males fertilize.

How Does the Pacific Viperfish Use Its Teeth to Hunt?

The Pacific viperfish is only 12 inches long. But it’s a great threat to small fish and crustaceans. The viperfish is a swift swimmer, easily catching up to its prey. Once it reaches a small shrimp or fish, it unhinges its enormous jaw to impale the creature and trap it inside its mouth. When it has caught its prey, it shuts its mouth and the little fish stays trapped inside a cage made of teeth. The viperfish then swallows the unfortunate creature whole. The viperfish have special shock-absorbing vertebrae behind their head. The viperfish can collide with their prey at high speeds without taking any damage.

The Viperfish’s Teeth Are Larger Than Its Mouth

These formidable teeth cause the viperfish’s lower jaw to protrude forward. The teeth sit outside of the mouth, interlocking, with two large lower fangs that curl upward reaching past the fish’s eyes. Because its jaw can unhinge, the viperfish can eat large prey for its size.

Pacific Viperfish Use Bioluminescence

Like many of the sea creatures that live at these depths, the Pacific viperfish relies on bioluminescence for camouflage. The fish has a line of glowing spots called photophores along its belly. The glowing stops shadows from forming when predators are looking down from above. This camouflage trick lets it blend into the ocean waters undetected by predators. The glow may also attract prey. Once the prey comes close, the Pacific viperfish can attack with its needle-like teeth.

A Mid-Level Predator

In the deep ocean, many creatures are both predators and prey. The viperfish is a mid-level predator, eating small fish and crustaceans. It’s also prey for some types of dolphins and sharks. The Pacific viperfish travels between the midnight and twilight zone from day to night. During the day, it hunts for food at depths around 5,000 feet, where sunlight can’t penetrate. At night, it swims upward, in search of richer food sources in the twilight zone.

Is the Pacific Viperfish Endangered?

We don’t know much about the Pacific viperfish. They are hard to study because they live in such great depths. They can’t live in captivity because they need to live where the pressure is great. The video from MBARI gives a rare look at a viperfish swimming around in its habitat.

The IUCN Redlist of Threatened Species lists all species of viperfish as that of least concern. However, very little is known of their population trend. Scientists are currently working to find out the effects deep sea mining may have on the creatures living in the deep ocean.