The ocean is a vast place with many unusual creatures, but none quite so striking as the viperfish. For instance, the sunfish can grow up to 14 feet vertically and weigh 5,000 pounds. The pointed sawfish actually looks like a saw. Even the seahorse, with its genderbending parenting, is a funny little sea-dwelling creature. One of the strangest and scariest looking fish, however, is the “viper fish.”

If you were asked to draw the scariest fish imaginable, your drawing would probably resemble this fish. Not only is it one of the ugliest and most terrifying looking fish, but it is also one of the most recognizable. You may not have known its name, but you have no doubt seen photos of the relatively small fish at some point.

As frightening as the viperfish is, though, it is truly one of the most fascinating creatures of the sea.

What Is a Viper Fish (Genus Chauliodus)?

viperfish against black background, white eyes, translucent teeth and gold-toned body

Image CC by A-SA 3.0 Unported, by Edd48, via Wikimedia Commons

The viperfish is one of the most ferocious hunters of the sea. The fish is classified in the genus Chauliodus and is recognized by its big mouth and sharp teeth. In fact, its teeth are so large that they do not fit inside of its mouth.

Although scientists do not know a whole lot about the fish, they believe it can travel two body lengths per second. In addition to its speed, the viperfish’s protruding lower jaw, fangs, and illuminating body make the fish a capable hunter despite its size which is between 12 to 24 inches.

According to the Environmental Literacy Council, the viperfish is a “scary-looking creature, but is no threat to humans.” They explain, one of the reasons the fish never bothers humans is because we almost never even see them. Actually, there are not even any photos of the viperfish in its habitat, the group says.

This isn’t surprising when you consider the viperfish lives thousands of miles under the sea in temperate to tropical waters. Also, it’s important to note that these are fish that do not ever live in captivity. When the viperfish is caught and brought to the surface of the ocean, it only lives for a few hours. This fact that it lives so far under the sea and its quick death upon being captured is the reason scientists do not have as much information as they’d like about the fish.

Reproductive habits

As a result, information about its reproductive habits has remained elusive. Scientists believe, however, that the fish are external spawners. This means that the female fish releases eggs in the water to be fertilized by males.

It’s important to note that there is more than one type of viperfish and they occupy almost all of the areas of the ocean.

Facts about the Pacific Viperfish

Pacific Viperfish photo

Image: CC by 2.0, by David Csepp, via Wikimedia Commons

The Pacific viperfish, known scientifically as Chauliodus macouni, is one of nine different “viper fish” currently recognized by marine biologists. This viperfish’s coloring can vary from black, silver, green. Like other viperfish, the Pacific species sports an unknown, thick, transparent substance that looks like scales. It is no longer than two feet and can live between 30 to 40 years in the wild, scientists estimate.

The fish is in the Northwest Pacific Ocean, from the Navarin Canyon in the Bering Sea to Japan. It is also found in the Eastern Pacific Oceans from Baja, California all the way up to the Gulf of Alaska.

Daytime habits of the viperfish

During the day, the Chauliodus macouni stays deep in the ocean, but at night it travels upward to water less than 1,900 feet deep where food is most plentiful. Because of this behavior, the Pacific viperfish is known as a “vertical migrator.” The fish mainly stays in the zone of the ocean known as the “Twilight Zone.” Only filtered sunlight reaches this zone, and many of the creatures that live on the sea floor hang out here.

When the Pacific species gets hungry, they capture their prey by luring it towards them with an illuminated dorsal fin (more on that later). Scientists do not believe the fish has a favorite food and eats a variety of little fish, including shrimp, anchovies, and crabs. It punctures the prey with its sharp fangs and swallows it whole. It has a large stomach, however, and can store a large quantity of food and go days without eating. Sometimes, though, the fish will catch prey that is more than half of its size, and it is forced to swallow by rotating its hinged skull.

Facts about Sloane’s Viperfish


Image: CC by 2.0, by OpenCage, via Chauliodus macouni

The Sloane’s Viperfish, Chauliodus sloani (cover image), is the most popular viperfish found in the sea and the silver-blue or green fish lives all over the place. Discovered by German scientists Marcus Elieser Bloch and Johann Gottlob Schneider the first description of the fish is in a book they co-authored in 1801.

According to Fish Base, Sloane’s viperfish is found in the south-central Atlantic, north of the equator in the eastern Pacific, western Mediterranean, northern Indian Ocean, South and East China Seas. Unlike some of the other viperfish, this one tends to stay in the same range of water depth day and night.

Interestingly, Sloane’s viperfish has the largest teeth of any fish even though it is relatively small as well. Its fangs are so large that it has to open its mouth vertically to swallow its prey. They are half the size of its head. Like the other viperfish, it has small lights along its body that attract smaller fish to it. When they get close, it uses its big teeth to capture and swallow them.

Another the way the fish differs from the Pacific viperfish is its diet. While the Pacific fish eats a wide variety of crustaceans and small fish, Sloane’s loves munching on lanternfish, eggs, and algae.

Viperfish dorsal fin: its secret weapon

Throughout this article, we have told you about the viperfish’s ability to lure its prey with its illuminated body. This is because it has light-producing organs called photophores.

The viperfish has three different kinds of photophores on its body. There are microscopic spheres that have no pigment in various places along the dorsal side. On the dorsal surface, bell-shaped organs with a pigment coat, lens, and reflectors are grouped together in rows. Finally, there are large spheres with reflectors, a pigment coats, and lens. The lateral and ventral surfaces have photophores as well.

The most important photophores on the dorsal fin at the top of the fish’s head. Scientists believe the viperfish float around for hours, waving the photophore on its dorsal fin to attract prey. When the prey gets close to the light, the viperfish goes in for the kill.

Watch this video about the viperfish:

Viperfish: We Still so Much to Learn

Hopefully, scientists will be able to tell us more about these fascinating fish soon. It has been more than 200 years since Sloane’s viperfish was discovered. Yet, we still have so much to learn about it and the other viperfish species. As research continues, it will be great to get photos of the fish in its natural habitat, while it hunts and more information about how the glowing creature reproduces.

It is reassuring to know that as nightmarish as it looks, scientists have assured us that the viperfish is not going to attack while your family is enjoying a nice day at the beach.


Featured Image: CC by A-SA 3.0 Unported, by Edd48, via Wikimedia Commons