This is one of my favorite predator fish of the deep, Viperfish, they are found anywhere between 250-5,000 feet below the water’s surface. They are found anywhere in the world and are also known as Sloan’s Viperfish or Sloan’s fangfish. The scientific name for this fish is Chauliodus sloani.

You may have recently seen a similar fish in an animated series, “Tell me, Dory, do you see anything?  …Yeah, I see a light… A light….  Yeah. I see a light. … Yeah, I see it too….. Hey, Conscience, am I dead?…. No, no. I see it, too….. It’s so… *pretty*. …I’m feeling… happy, and that’s a big deal… for me…. I want to touch it… Oh!..  Hey, come back. Come on back here. I’m gonna get you….  Come here…. I’m gonna swim with you… I’m gonna get you. I’m gonna get you…. I’m gonna be your best friend.. …Good feeling’s gone” Does this quote ring any bells? Yes, a similar fish to our viperfish, the anglerfish, made an appearance as a antagonist on Finding Nemo and lured Marlin and Dory in as it’s prey.

One of the most unique factors about this fish is that it has a long dorsal spine that has been tipped with a photophore, which is a  light-producing organ. Using this light organ, in a way somewhat similar to a fishing lure, is how it attracts its prey, like Marlin and Dory in the above example. This is done through a process that is called bioluminescence. The primary light organ is at the end of the lengthened dorsal fin ray, even so, there are plenty more photophores located throughout the side of the viperfish. These may help to camouflage the fish from predators lurking below. The lights, which show a purple hue with red dots, help to make blend the viperfishes lower half with a very faint light that is filtered from above.

Normally, the viperfish will flash this light to attract its prey. It is still uncertain how this fish kills its prey, but it is assumed that it uses its sharp teeth to impale victims, these same teeth that are too large to fit in the fish’s mouth and reach up close to the fish’s eyes in length. A big reason that this is assumed is due to the shock absorbing vertebrae found behind this fish’s head. The viperfish also has the ability to enlarge the size of its stomach to be able to digest its prey, if  the prey is larger than itself. Oddly enough, viperfish do not chew on their prey, despite their menacing teeth.

This fish may seem to be ferocious by definition of looks and its predatory nature, but they are not very large, oddly enough. These fish typically are around 11 to 12 inches, so pull out your ruler and there is the average length for this fish. Often, this fish is a dark silvery blue in color, but there have been sightings of green, silver, and black for this fish as well.

The migration of viper fish is believed to be vertical diurnal, which means that Viperfish are found to stay in the lower depths during the day and in the more shallow regions of it’s territory at night. The territory of these fish is known as the bathypelagic region, or the midnight zone, I prefer midnight zone because it’s simpler to say. This zone is one of the five zones the water is divided into and this zone is anywhere from 330-13,200 feet below the surface. In case you are unaware of the regions of the water here they are in order of closest to furthest from the surface: Epipelagic zone (Or Sunlight zone), Mesopelagic zone (the Twilight Zone), Bathypelagic zone (Or Midnight zone),  the Abyssopelagic zone (Or the Abyss), and lastly is the Hadal zone (or the Trenches). There is virtually no sunlight in the midnight zone, which explains why the viperfish are bioluminescent.

It is  very difficult to study these fish, due to they are only able to live a few hours in captivity. Although not very much is known presently about the life span of these fish, researchers have concluded that they probably live between 15 and 30 years. When it comes to mating for these creatures, it is believed that they are external spawners, which simply means that the female releases eggs into the water to be fertilized. It is assumed that this happens throughout the year. The numbers of the young larvae of viperfish, have been noted that the highest amount are born between January and March. Viperfish larvae are around a quarter of an inch long when hatched, and are similar in looks to that of a eel. The babies are left to fend for themselves until maturity.

These creatures are fascinating and I hope we can discover more about them in the near future. I hope you enjoyed this look into the deep sea!