Deep Sea Exploration. NOAA. Attribution: By NOAA (courtesy of NOAA for caliornia Academy of science) [Public domain], via Wikimedia Commons Public Domain.

Deep Sea Exploration. NOAA. Attribution: By NOAA (courtesy of NOAA for caliornia Academy of science) [Public domain], via Wikimedia Commons
Public Domain.

Deep ocean animals get a reputation for being creepy and grotesque. Razor sharp teeth, the ability to produce their own light, and to live under even the most extreme conditions make them perfectly suited for the term ‘sea monsters.’ Even so, these infamous deep sea creatures have amazing attributes that you won’t be able to find anywhere else. Let’s take a look some of the ocean’s most interesting deep sea monsters!

Life below the light

Ocean creatures that live below 1000 meters have some unique adaptations to help them live in a part of the planet that most would consider uninhabitable. These animals live in the aphotic zone, the part of the ocean where there is no light. The deep parts of the ocean are also under very high amounts of pressure, are extremely cold and have areas of low oxygen.

Despite having no access to natural light, some deep ocean animals produce their own light, called bioluminescence. Bioluminescence has many purposes, but the most obvious is to help illuminate their surroundings (1). Another interesting adaptation deep sea animals have to deal with, in terms of no light source, has to do with the basis of their food web. Most areas of the world rely on sunlight to power photosynthesis, which is the basis for all energy within a food web. Since there is no light to allow for photosynthesis in this area of the ocean, these animals have to rely on detritus (decaying organic matter) and dead organisms that sink to the bottom of the ocean for energy, while others rely on chemosynthesis (1,3).

Ever wondered how creatures of the deep are able to live under such immense pressure while humans cannot? The answer, in part, is due to their cell membranes. Deep ocean creatures have cell membranes that are made out of an extremely fluid material, and this helps in more ways than one (1,4). The problem with pressure occurs when the pressure of the inside of a cavity (such as lungs or deep sea submersibles), is lower than that of its surroundings. For a pair of lungs, the pressure of the deep sea would be crushing. However, for the fluid and lipid filled ocean creatures this is not a problem. Most deep ocean animals do not have much gaseous space in their body cavities, which allows for them to equalize pressure between the insides of their bodies and the surroundings (4). The fluid- like lipid membranes allow for the animals to withstand the extra force of the increasing pressure without collapsing. This capability also allows for the animals in the deep sea to withstand frigid temperatures. The unique lipid structure of their cell membranes will not freeze or become rigid with a decrease in temperature (1).

Areas low in oxygen are generally hard to come by in the deep ocean, because colder waters hold more dissolved oxygen. However, there are a few oxygen depleted zones where there are no oxygen enriched currents to supply it or photosynthesis occurring. Even still, there are animals able to survive under such conditions. Scientists studying one such zone in the Mediterranean Sea found metazoans that could live their entire lives without oxygen, even reproducing in these environments (2). These sea creatures opted out of using mitochondria in their cells in favor of different cell organs that allow them to live anaerobically (2). With much of the sea floor left to be explored, this finding has large implications for scientist’s understanding of sea life below 1000 meters.


Deep Sea Animals

Vampire Squid

Vampire Squid Attribution:Vampire squid by Carl Chun, 1903. Image from the NOAA Photo Library (Public Domain) {{PD-USGov-NOAA}} Category:Vampyroteuthidae Contributor:  Dbenhuser Public Domain.

Vampire Squid
Attribution: Vampire squid by Carl Chun, 1903. Image from the NOAA Photo Library (Public Domain) {{PD-USGov-NOAA}} Category:Vampyroteuthidae
Contributor: Dbenhuser
Public Domain.

Despite their ominous name, Vampire Squid are relatively harmless. The name ‘vampire’ was attributed to this type of squid because of its large, sometimes red eyes and webbed tentacles, which appear to look like a cloak. With a body size toping six inches and lacking the ability to produce ink, their main form of protection is their bioluminescence (to distract or scare predators) and their webbing, which they can pull above their head to protect vital organs. The Vampire Squid is able to move quickly through the water by using its fins, located at the top of its head like ears, to propel them forward (5). They eat prawn and other small invertebrate and are prey to seals, whales and other large deep sea fish. Vampire Squid are unique in that they can go for long periods of time without eating and can survive in the oxygen minimum zone (approximately 600 meters below sea surface.) They can do this by slowing down their metabolic rate, which means they require far less food and oxygen to survive (5).

Pacific Blackdragon

Looking like a dragon out of a fairy tale, the Pacific Blackdragon only has two things on its mind: where its next meal is coming from and finding a mate. While both male and females share the common traits of rare occurrence and a dark black appearance on the outside and inside of their bodies (to hide any bioluminescence of a recently eaten meal), it is the female that really steals the show. She has several rows of bioluminescent bulbs along her body to attract a mate, a well-lit bulb on the end of a lure attached to her chin to catch prey, and several large teeth. Males only live long enough to mate and die shortly after, so they do not need all of the special adaptations that females do to get by (6).

Deep Sea Fish

Atlantic Wolffish

Atlantic Wolffish Attribution:By Kamil Porembiński (Flickr: Seawolf) [CC BY-SA 2.0 (], via Wikimedia Commons License:

Atlantic Wolffish
Attribution:By Kamil Porembiński (Flickr: Seawolf) [CC BY-SA 2.0 (], via Wikimedia Commons

Don’t let the large canine-like teeth and five foot frame fool you, the Atlantic Wolffish is more of a gentle giant, and an important one at that. The Atlantic Wolffish prefers more intermediate depths than truly deep waters (greater than 1000 meters) and is considered a key stone species, controlling populations of urchin(6). While they may not be considered aggressive, the Wolffish uses his hard teeth to crush his prey (mainly hard bodied invertebrate.) Over time this wears down their teeth, requiring them to be replaced, during which time they fast (7). Scientists have found over recent decades that numbers of Atlantic Wolffish are on the decline, placing them on the list of Species of Concern in the United States (6). Drops in Atlantic Wolffish could have large impacts on the population of urchin and shellfish throughout their natural range.

Snaggletooth Fish (Stareater)

While there is not much known about the Snaggletooth Fish, for this guy a picture can be worth a thousand words. Generally only growing to be about 21 cm in length, the Snaggletooth is known to be a predatory fish preferring the mid-range to deep waters between New Zealand and Australia. It has long curved, needle-like teeth, and a barbel attached to its chin that glows red, enticing its prey (8).


At only about a foot long, it may be surprising to know just how terrifying a Viperfish is. Viperfish have fang-like teeth that are so long that they cannot fit them in their mouths. They use this to their advantage though, darting after prey using their teeth to impale them (5). Viperfish possess a long spine attached to their back with a bioluminescent bulb to attract prey, and can be found motionless in the water waiting for a small fish to approach. They prefer temperate and tropical waters and can be found at depths of 1500 meters, coming up closer to the surface to find food at night (5).

Deep Sea Sharks

Goblin Shark

Goblin Shark. Attribution:By Waite, Edgar R. (1866–1928) ([1] Scan by Marine Image Bank.) [Public domain], via Wikimedia Commons Public Domain.

Goblin Shark.
Attribution:By Waite, Edgar R. (1866–1928) ([1] Scan by Marine Image Bank.) [Public domain], via Wikimedia Commons
Public Domain.

At first glance, a Goblin Shark looks more like a ghost with its pale coloring and graceful stature. But a closer look reveals a long snout with the hidden ability to locate prey in the dark, long and jagged teeth so numerous they can’t all fit in its mouth, and an unhinging jaw suitable to grasping any prey (6). Goblin Sharks live at or below 1300 meters and without bioluminescence it would be reasonable to think that these sharks would have a difficult time finding food in the complete darkness of the deep ocean. The Goblin Sharks have found a clever way around this though. Their snouts are coated with a special lining allowing it to detect the electric field of approaching fish (6). Once a fish has been sensed, the Goblin Shark unhinges its jaw and makes it a meal!


This prehistoric giant may not be a part of the ocean ecosystem anymore but its amazing size and the misconceptions surrounding it make it noteworthy for this article. The Megalodon topped more than 50 feet and is thought to have eaten whales and other large marine animals. More recent studies suggested that the jaws of this massive ocean creature were so strong, they could have crushed cars (9). Despite reported sightings in different parts of the world, the commonly purported ‘meglodon’ has been extinct for millions of years. It is hypothesized that as the Pacific and Atlantic Oceans were separated by landmasses, it prevented mixing of water and ultimately cooled the Megalodon’s natural range. This, combined with the rise of animals that preferred to hunt in groups which out competed the solitary animal for food made for a scenario in which the Megalodon could not adapt (9).

Frilled Shark

Yet another eel-like deep ocean animals, the Frilled Shark looks like it belonged during the Megalodon’s life time. The shark lives so deep in the water that very little is known about it, as its usually only seen when it is accidently caught in deep waters (6). Coming in at 7 feet long, the Frilled Shark moves quickly, being able to lunge at its prey and swallow it whole. It is rarely seen alive, giving scientists the notion that it is likely naturally a rare animal. This makes it especially susceptible to extinction as it tends to be caught and killed by deep sea fishing expeditions (6).


Sea animals are beautiful and absolutely necessary to the ecosystem, even the ones that prefer to inhabit the deep ocean. In many ways, they help keep the ocean clean and healthy by adapting to eat decaying organic matter and thus maintaining a healthy ecosystem. Even if you can’t see them, deep sea animals are there, making the ocean a better, more interesting place.


  1. “The Deep Sea Ocean biology, Marine life, Sea creatures, Marine conservation…”. MarineBio Conservation Society. Web. Dr. Paul Yancey/MarineBio. Updated 29 December 2011. Accessed 12:15 PM 6/23/2015.
  2. Fang, Janet. ‘Animals Thrive Without Oxygen At Sea Bottom’ Nature International Weekly Journal of Science. Apr. 6 2010. Accessed June 23, 2015.
  3. Svitil, Kathy. ‘Survival Beneath the Surface.’ Savage Seas, PBS Online. Accessed June 24, 2015.
  4. Kunzig, Robert. ‘The Physics of…Deep Sea Animals.’ Discover Online. Aug. 1, 2001. Accessed June 23, 2015.
  5. ‘Creatures of the Deep Sea Deep Sea Creature Database.’ Sea and Sky Presents the Sea. Accessed June 23, 2015.
  6. ‘Ocean Animal Encyclopedia.’ Oceana. Accessed June 25, 2015.
  7. ‘Species of Concern Atlantic Wolffish Anarhichas lupus’ NOAA National Marine Fisheries Service. May 17, 2007. Accessed June 25,
  8. Stewart, Andrew. ‘Science Report. Denizens of the Deep: daggertooth and stareater.’ Museum of New Zealand, Te Papa Tongarewa. 2008. Accessed June 25, 2015.
  9. Than, Ker. ‘The Real Megalodon: Prehistoric Shark Behind Doc Uproar.’ National Geographic. Aug. 7, 2013. Accessed June 25, 2015.