Which Creature Lives at the Greatest Depth below Sea Level?

It takes around four hours to get to the lower reaches of the Mariana Trench, located near Guam in the Pacific Ocean. In a series of deep-sea dives conducted in 2014 and 2017, British and American researchers left traps equipped with cameras to find out what lifeforms survive in the deepest parts of the world's oceans. What they discovered was a new species of snailfish living at a record depth of 26,200 feet (7,986 meters). The small, slimy, and translucent fish is now known as the Mariana snailfish, and currently holds the title of Earth’s deepest fish.

Deep, deeper, deepest:

• The researchers explained that Mariana snailfish “are free of predators, and the funnel shape of the trench means there’s much more food. They are active and look very well-fed.”
• Earlier this year, Japanese researchers filmed snailfish swimming as deep as 26,830 feet (8,178 m) below sea level, but they didn’t recover any samples.
• The scientists say they are unlikely to discover other fish that can live even deeper than this new species. Below a certain threshold, the crushing pressure becomes so powerful that it destabilizes proteins.

Frequently Asked Questions

Which creature holds the record for living at the greatest depth below sea level?

The Mariana snailfish (Pseudoliparis swirei) holds the record for the deepest living fish, observed at depths of about 8,178 meters (26,831 feet) in the Mariana Trench. This small, translucent fish has adapted to the extreme pressure and cold of the deep-sea environment.

How do creatures adapt to the extreme conditions found in the deepest parts of the ocean?

Deep-sea creatures have evolved unique adaptations to survive the crushing pressure, darkness, and cold. They often have flexible, soft bodies to withstand pressure, slow metabolisms to conserve energy, and specialized feeding mechanisms to exploit scarce resources. Bioluminescence is also common for communication and attracting prey.

What is the Mariana Trench and why is it significant for deep-sea life?

The Mariana Trench is the deepest part of the world's oceans, reaching depths of over 36,000 feet (nearly 11,000 meters). It's significant for deep-sea life because it hosts unique ecosystems with organisms that have adapted to the extreme pressures, which can be over 1,000 times the atmospheric pressure at sea level.

Are there any microorganisms that can live deeper than the Mariana snailfish?

Yes, microorganisms known as extremophiles can live at even greater depths. For example, single-celled organisms have been found in the Challenger Deep, the deepest known point in the Mariana Trench, at depths exceeding 36,000 feet (10,994 meters). These organisms can survive in conditions that would be lethal to most other life forms.

What technological advancements have allowed us to explore the deepest parts of the ocean?

Advancements in deep-sea submersibles and remote-operated vehicles (ROVs) have enabled exploration of the ocean's deepest parts. Innovations in materials science have led to the development of pressure-resistant hulls, while improvements in cameras and lighting systems allow us to capture images and data from these previously inaccessible environments.

How does the pressure at the deepest part of the ocean compare to that at sea level?

The pressure at the deepest part of the ocean, such as the Challenger Deep in the Mariana Trench, can exceed 1,086 bars (15,750 psi), which is over 1,000 times the atmospheric pressure at sea level. This extreme pressure is equivalent to having about 50 jumbo jets piled on top of a person.