Deep Sea Creatures

Human curiosity has always been fascinated by the weird creatures of the deep. Hundreds and hundreds of metres beneath the ocean, lie many unknown and elusive creatures that have never been studied or seen before.  In the most hostile, bizarre and strangest environment on Earth, its fishy inhabitants are exposed to extremely low levels of light and oxygen, extremely high levels of pressure, and water temperatures that range from -1.8°C  to 3°C (28F - 37F), unless you are swimming by a thermal ecosystem provided by an underwater volcano, where the temperature is a balmy 350°C (662F) or higher. Toasty.  It is no wonder that we have such a fascination of weird and strange deep sea creatures who appear more like aliens than animals.

Features and Characteristics

Because of the stark contrast between our environment and the conditions of the deep sea, most fish that inhabit this harsh environment don’t survive in laboratory conditions, and attempts to keep them in captivity have also led to their deaths.  Because of the pressure at those depths of the ocean, deep sea creatures have evolved to have gas-filled spaces, or sacs, known as vacuoles, because gas is compressed under high pressure and expands under low pressure. Because of these vacuoles, these deep sea organisms have been known to blow up if they come to the surface. The creatures can also suffer from decompression sickness, which also causes them to die. It is because of the difficult nature of transporting and providing a pressurized environment that little is known about the creatures of the deep.

These creatures of the deep have also evolved to combat the lack of light at such great depths. Most deep sea creatures are blind, and rely on other senses to find and catch their prey, as well as avoid their predators. Some creatures that aren’t blind rely on their bioluminescent eyes, which are as much as 100 times more sensitive to light than the human eye. Many deep sea creatures also rely on camouflage, and are therefore clear or dark in colour.

The Blobfish


Found in the deep waters of the coast of mainland Australia and Tasmania, this miserable looking fish is known as the Blobfish. The Blobfish is rarely seen by humans, as it lives at depths ranging from 600-1200 metres (2000-3900 feet).

Instead of using gas bladders for movement and buoyancy, the Blobfish’s flesh is predominately gelatinous in nature, with a density slightly less than water, which allows it to float above the sea floor without wasting energy on moving or swimming. Its lack of muscles doesn’t hinder its hunting abilities, as it just swallows whatever invertebrates that float in front of it, like crabs and sea pens.

The Blobfish probably looks so sad because they are currently facing extinction, as they continually being, caught, dragged up and killed in deep sea nets from fishing trawlers.



With its scientific name ‘Anoplogastridae’ meaning ‘unarmed stomach’, the Fangtooth fish is another mysterious creature of the deep. The Fangtooth fish is named after its large, disproportioned fang-like teeth, so big that it has the largest teeth of any fish in the ocean, proportionate to body size.

Fangtooth fish have been found as far as 5000 metres (16400 feet), but are more commonly seen between 200-2000 metres (660-6560 feet). Even with their natural habitat being so deep beneath the surface of the ocean, Fangtooth fish have shown to be more resilient than other deep sea creatures, as they have been kept alive in aquariums for months, despite not having the same deep sea pressure conditions.


Sloane's Viperfish

While there are multiple types of Viper and Dragon fish, Sloane’s Viperfish holds the world record for the largest teeth proportionate to head size in a fish. When its mouth is closed the teeth protrude out over the jaws, and to swallow its prey, it has to open its mouth wide enough to make its jaws vertical. To eat larger prey, Sloane’s Viperfish will lower its internal gills, which allows for the food to pass through the throat and into the stomach without any blockage occurring. Sloane’s Viperfish can also swim at its prey and impale them on its teeth, using the first vertebra behind its head as a shock absorber

Found at depths around 2500 metres (8200 feet), Sloane’s Viperfish ranges in length between 20-35 centimetres (7-1 3 inches).

Sloane's Viperfish

Want More?

Interested in reading more on the wacky world of the deep sea? Read another article about the most mysterious and elusive creature of the deep, the Giant Squid!