Dispatches From the Deep Pacific

By: Sophie R. Sanchez, Christine A. Parisek, Andrew L. Rypel

Background photo by Jeremy Bishop on Unsplash. Phylopics by Christopher Kenaley (Sternoptyx pseudobscura; CC0 1.0), Yan Wong (Malacosteus niger; CC0 1.0), C. Camilo Julián-Caballero (Chauliodus danae; CC BY 3.0), Erika Schumacher (Anoplogaster cornuta; CC BY-NC 3.0). Font by Charlie Samways (CC0 1.0). Text inspired by Game of Thrones, “Winter is Coming”.

Monsters are lurking…

Off the coast of California, down in the chilly depths of the Pacific Ocean, there lie the most unsettling denizens that appear summoned from the nightmares of Mira Grant. Here in the inky blackness, where nature spawned these most otherworldly configurations, inhabitants reign in pure darkness. Even the bravest of brave souls may not be able to suppress a shudder after reading this post. Prepare to endure a frightful encounter with some of nature’s most sinister and vile entities…

Fangtooth (Anoplogaster cornuta). Image credit: David Wrobel.

Fangtooth (Anoplogaster cornuta) – Adorned with malevolent fangs that provide its namesake, the fangtooth has a Dracula-esque bite and haunting charm which commands pure respect in “the midnight zone” of their oceanic abyss. The fangtooth’s ultra-black pigmented skin also absorbs light with 99.5% efficiency, practically providing this fish with a natural cloak of invisibility. As if that weren’t enough to give you the heebie-jeebies, these carnivores also have powerful musculature, enlarged heads, bulging eyes, and enormous gnashing jaws to help ambush and snatch unsuspecting prey. Indeed these primordial hunters are the quintessential model of predatory elegance, with a bioluminescent lure allowing them to play games, waiting patiently to execute the lethal strike. There are just two known species of fangtooth lurking in the world: common fangtooth (Anoplogaster cornuta) and, as if they could be any more formidable, shorthorn fangtooth (Anoplogaster brachycera). Great, just what it needed, an extra weapon.

Pacific viperfish (Chauliodus macouni). Image Credit: David Wrobel.

Viperfish (Chauliodus macouni) – Not to be confused with the Bulgarian punk rock band, the viperfish is one of the primary predators of the mesopelagic zone of the Pacific. Viperfish are quickly recognized by their massive fangs, resembling in many ways, a fishy vampire. These ghoulish creatures possess one of the largest teeth-to-head size ratios known on Earth. Amazingly, they can also unhinge their jaw to at least a 90° angle to take even bigger bites. Ultimately, these adaptations help ensure any prey captured by viperfish are most definitely consumed with no chance of escape. Meals are hard to come by in the deep sea, and viperfish therefore strike fear into the hearts of any planktivore also occupying our deep California coasts. Planktivorous and zooplanktivorous fishes make massive diel and crepuscular migrations up and down the water column, but viperfish lie and wait. Waiting for their chance to jump and kill. Its face and unsightly visage alone are enough to make one’s skin crawl, but imagine the heart-pounding reality of being confronted face-to-face with such a deadly creature.

Hatchetfish (Sternoptyx obscura). Image credit: Paul Caiger / Woods Hole Oceanographic Institution.

Hatchetfish (Sternoptyx obscura) – Shaped like the terrifying tool of choice by countless thriller antagonists (“heeeeeere’s Johnny”, anyone?), the hatchetfish lives up to its namesake. Cutting through a wide range of depths with its razor-thin body, this deep-sea fish bears a constant ghastly expression for all to shudder at. That is, if you ever see it at all. In a mystical feat of counterillumination, hatchetfish use light-producing organs called photophores along their underside to conjure up light nearly identical to the ambient environment. Now invisible to creatures viewing them from below, they eerily glide through the waters as phantoms of the sea. While you can’t see them, hatchetfish can definitely see you – bad news for us all. Their bulging eyes grasp even the slightest twinkle of light, and can focus on unassuming prey both near and afar. Protruding from the abyss, their nightmarish eyes are the last sights of luckless prey before they meet their fate…

Blackdragon (Idiacanthus antrostomus) – Blackdragon fish don’t just skulk in the dark; they are the dark. Female blackdragon are unnervingly ultra-black, absorbing 99.5% of light around them like their horrifying counterpart, the fangtooth. Their teeth, jagged and sharp, are similarly anti-reflective to prevent detection by prey. While the prospect of encountering this eel-like predator is enough to make anyone fear the dark, the light can’t be trusted either. Adorned with a long, wispy barbel dangling from their chin, blackdragon fishes use a light-producing organ found at the end of this barbel (chin) to attract unexpecting victims. The snap of their fangs proves an unpleasant surprise for countless crustaceans and fishes.

Even scarier? The fate of male blackdragon. Doomed to a life stunted in a larval-like phase, males completely lack a mouth and stomach. They live just long enough to mate before succumbing to their physiology. This sexual dimorphism, while an incredible adaptation to resource limitations and the need for genetic diversity, is terrifyingly polar: a mouth of violent teeth versus well, no mouth at all. We don’t know which is scarier.

Pacific Blackdragon (Idiacanthus antrostomus). Image Credit: K. Osbourn / Smithsonian National Museum of Natural History.


Lurking in the dark with their needle-like teeth, these deep-sea creatures seem like perfect candidates for the next JAWS film…but we won’t quite be needing a bigger boat.

Did we mention that all these fishes are actually super tiny and can fit in the palm of your hand? BOO!

Upper left: The common fangtooth (Anoplogaster cornuta) is actually only up to 6 inches (15.2 cm) in length. Their teeth are among the largest (in proportion to body size) of any fish in the ocean. Image Credit: NOAA Photo Library. Upper right: The Pacific viperfish (Chauliodus macouni) is actually only up to 12 inches (30 cm) in length and remains an excellent band name. Image credit: iNaturalist/hfb, Lower left: The Hatchetfish (Sternoptyx obscura) is actually only up to 3 inches (8 cm) in length. It remains a fearsome predator, but only to small crustaceans and plankton. Image credit: martychums / Instagram. Lower right: While female Pacific Blackdragon (Idiacanthus antrostomus) may reach 24 inches (61 cm), males reaching a whooping maximum of… 3 inches (8 cm). What they lack in stature they make up for in horror! Image credit: iNaturalist/stercorariidae.

Sophie R. Sanchez is a Junior Specialist at the Center for Watershed Sciences at the University of California, Davis. Christine A. Parisek is a Ph.D. Candidate in the Graduate Group in Ecology at UC Davis and a Science Communications Fellow at the Center for Watershed Sciences. Andrew L. Rypel is a professor of Wildlife, Fish, & Conservation Biology and Director of the Center for Watershed Sciences at the University of California, Davis.

Further Reading:

Fangtooth (Anoplogaster cornuta) –
-Monterey Bay Aquarium: Fangtooth, https://www.montereybayaquarium.org/animals/animals-a-to-z/fangtooth
-iNaturalist: Fangtooth, https://www.inaturalist.org/taxa/86493-Anoplogaster

Pacific Viperfish (Chauliodus macouni) –
-Monterey Bay Aquarium: Viperfish, https://www.montereybayaquarium.org/animals/animals-a-to-z/pacific-viperfish

Hatchetfish (Sternoptyx obscura) –
-Monterey Bay Aquarium: Hatchetfish, https://www.montereybayaquarium.org/animals/animals-a-to-z/hatchetfish
-Woods Hole Oceanographic Institution: Creature Feature: Hatchetfish https://twilightzone.whoi.edu/explore-the-otz/creature-features/hatchetfish/

Pacific Blackdragon (Idiacanthus antrostomus) –
-Monterey Bay Aquarium: Pacific Blackdragon, https://www.montereybayaquarium.org/animals/animals-a-to-z/pacific-blackdragon
-Oceana: Pacific Blackdragon, https://oceana.org/marine-life/pacific-blackdragon/

New York Times: How Ultra-Black Fish Disappear in the Deepest Seas – https://www.nytimes.com/2020/07/16/science/ultra-black-fish.html

Davis, A.L., Thomas, K.N., Goetz, F.E., Robison, B.H., Johnsen, S. and Osborn, K.J., 2020. Ultra-black camouflage in deep-sea fishes. Current Biology, 30(17), pp.3470-3476.

Monterey Bay Aquarium: Deep Sea Fishes, Habitat, Adaptations – https://www.montereybayaquarium.org/animals/habitats/deep-sea

Freer, J.J. and Hobbs, L., 2020. DVM: the world’s biggest game of hide-and-seek. Frontiers for Young Minds, 8.

Learn about the Bulgarian progressive punk rock band, Viperfish: https://en.wikipedia.org/wiki/Viperfish_(band)

About Andrew Rypel

Andrew L. Rypel is a Professor and the Peter B. Moyle and California Trout Chair of coldwater fish ecology at the University of California, Davis. He is a faculty member in the Department of Wildlife, Fish & Conservation Biology and Director of the Center for Watershed Sciences.
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1 Response to Dispatches From the Deep Pacific

  1. Jaun says:

    When you see photos of just these cuties with no size reference we all conjure up a 7 ft 200 lb image

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