Snailfish sink to new lows to extend their record as the world’s deepest fish (2023)

Scientists recently exploring some of the world’s deepest oceanic trenches in the North Pacific have redefined the known limits that fish can survive.

On 15 August 2022, a juvenile Pseudoliparis snailfish (species yet to be determined) was captured on film investigating a baited camera 8,336 m (27,349 ft) below the surface in the Izu-Ogasawara Trench off Japan. It claims the undisputed record as the world’s deepest fish.

@guinnessworldrecords Deepest fish - Pseudoliparis snailfish at 8,336 metres (27,349 ft) 🐠 #guinnessworldrecords#worldrecord#fishtok♬ original sound - Guinness World Records

The unprecedented depth – more than double the vertical extent of Mount Fuji – is approaching what is thought to be the biological bottom line for fish.

Snailfish sink to new lows to extend their record as the world’s deepest fish (1)Snailfish sink to new lows to extend their record as the world’s deepest fish (2)

Just days later, during the same expedition, two P. belyaevi snailfish were successfully retrieved from a depth of 8,022 m (26,319 ft) in the nearby Japan Trench. A watershed moment, this is the first time that any fish have been caught categorically from below 8,000 m (26,247 ft).

Snailfish sink to new lows to extend their record as the world’s deepest fish (3)

The snailfish were documented by marine biologists from the University of Western Australia (UWA) and the Tokyo University of Marine Science and Technology (TUMSAT), during a two-month survey on the research vessel DSSV Pressure Drop (since renamed Dagon). The expedition was supported by Caladan Oceanic and Inkfish, with filmmakers from the Japanese broadcaster NHK also on board.

Snailfish sink to new lows to extend their record as the world’s deepest fish (4)

The chief scientist conducting this field study was UWA Professor Alan Jamieson, founding director of the Minderoo-UWA Deep-Sea Research Centre. A consultant for GWR on deep-sea marine life, Professor Jamieson is arguably the world’s leading authority on hadal organisms – i.e., those that live deeper than 6,000 m (19,685 ft) – and has made numerous record-setting discoveries over his career.

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Snailfish sink to new lows to extend their record as the world’s deepest fish (5)

These include the deepest squid(6,212 m; 20,381 ft), the deepest octopus(6,957 m; 22,825 ft), the deepest decapod(7,703 m; 25,272 ft) and the deepest hydrozoan(10,063 m; 33,015 ft), to name just a few.

Snailfish sink to new lows to extend their record as the world’s deepest fish (6)Snailfish sink to new lows to extend their record as the world’s deepest fish (7)

Given his fathomless expertise in this area, was he surprised to find a snailfish so far down, when he himself has proposed that the absolute maximum for fish lies not much beyond this point? “The limit of 8,200 m [26,903 ft] came with the caveat of it being in the region of 8,200–8,400 m [26,903–27,559 ft] as temperature likely plays a part here,” Professor Jamieson told GWR.

“Temperature and pressure have similar perturbing effects on cells, therefore warmer waters should allow fish to go deeper.” He continued: “Two years ago, we published a paper on all ultra-deep-sea fish and concluded that the deepest is likely off Japan as the trenches there are both deep enough and slightly warmer than the previous record in the Mariana Trench. And hey presto, there it was!”

"The 8,200–8,400-m limit is pretty solid. Fish use an osmolyte in their cells that balances pressure, essentially stopping the cells imploding at depth! It is called Trimethylamine-n oxide (TMAO for short). Concentrations of TMAO increase in cells with depth and the region where it reaches isosmosis – i.e., saturation point, when they can’t put any more in – is 8,200–8,400 m" - Professor Alan Jamieson

As Professor Jamieson alludes to, this isn’t the first time that snailfish have hit the headlines for plunging to record lows in the ocean.

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Prior to this, the deepest fish on record was a Mariana snailfish (P. swirei) observed at 8,178 m (26,831 ft) in the Mariana Trench in the western Pacific on 18 May 2017. This was reported by the Japan Agency for Marine-Earth Science and Technology (JAMSTEC) and NHK in August 2017.

This sighting came in the wake of another yet-identified snailfish species at 8,145 m (26,716 ft) – for now dubbed the “ethereal snailfish” – also in the Mariana Trench, filmed by Professor Jamieson in 2014.

Situated around 320 km (200 mi) south-west of Guam, the Mariana Trench is home to the oceans’ deepest point: the 10,935-m (35,872-ft) Challenger Deep.

It begs the question could another snailfish – or indeed a different fish species – be found even deeper still? Either in the 9,780-m (32,087-ft) Izu-Ogasawara Trench, the Mariana Trench or in another ocean trench entirely?

Snailfish sink to new lows to extend their record as the world’s deepest fish (8)

Professor Jamieson believes we are close to hitting a baseline. “Since we first started finding these snailfish around 2007–10, and the TMAO hypothesis was established (in 2014), we have done an exponentially increasing number of visits with baited cameras.

“We have now done 500 deployments of deep-sea cameras all over the world, and so our understanding of where these fish are has progressed a lot.

“Pretty much every film up to 8,336 m has fish in it, and then they simply disappear after that. We have honed into this limit in such a way that if a deeper fish is found it is likely no more than a few tens of metres, and probably then, falling within the error bars of the depth sensors. I think this might be the last significant increase in their maximum depth.”

"[After snailfish] the next deepest fish are the grenadiers (Macrouridae) and cusk eels (Ophididae), which occupy most of planet Earth, but despite such huge horizontal distributions, they pretty much drop off at a depth of around 7,200 m (23,622 ft), and usually shallower. After then, it appears to be snailfish all the way" - Professor Alan Jamieson

Certain snailfish have been able to push beyond the depth barrier of all their other kin owing to a number of special adaptations that enable them to withstand the extreme conditions. These evolutionary attributes include a largely cartilaginous skeleton and also gaps in their skulls to allow for the immense pressure, which beyond 8,000 m can exceed more than 800 times that at the surface.

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Snailfish sink to new lows to extend their record as the world’s deepest fish (9)Snailfish sink to new lows to extend their record as the world’s deepest fish (10)

However, these traits are not shared across the whole family, as Professor Jamieson explains: “There are 300 species of snailfish and most of them are shallow, even estuarine. They have percolated down into the depths during their radiating evolution and now we have a multitude of ultra-deep snailfish that live 1,000 m [3,280 ft] deeper than any quintessentially ‘deep-sea’ fish.

“It is perhaps their lack of swim-bladder, gelatinous body and efficiency in consuming small crustaceans that happen to be in the trenches, that have made them so successful.”

While the 8,336-m snailfish is garnering much of the media spotlight in terms of it fundamentally being the deepest recorded fish in history, Professor Jamieson is eager to emphasize the significance of the two P. belyaevi specimens that were collected five days later, slightly higher at 8,022 m in the Japan Trench.

Snailfish sink to new lows to extend their record as the world’s deepest fish (11)Snailfish sink to new lows to extend their record as the world’s deepest fish (12)

So how do you go about fishing at depths akin to 90% the height of Mount Everest? “We use standard fish traps from the local fishing shop, pop a bit of bait in it and tie to a $200,000 deep-sea camera,” Professor Jamieson revealed. “A lovely mix of hi-tech meets low-tech!”

He continued: “We film a significantly larger number of snailfish than we ever catch, and I am happy with that. I don’t really want to catch them; I’d rather learn as much from videoing them than having to bring them up.

“But, to know what it is, how genetically related they are to other populations, how they survive, what they eat and things like the TMAO-driven limit, we must bring up what we call ‘voucher specimens’. Normally one or two fish is enough for this type of work.”

As you might suspect given their native pitch-black habitat several kilometres below the waves, which until relatively recently has been out of reach to humans, the record for the deepest fish has had a complex and at times controversial history. A few past contenders have been thrown into doubt as more light is cast on the hadal world thanks to advances in technology and the dedicated research of explorer-scientists like Professor Jamieson.

One such of these was the so-called “Trieste flatfish”. It was reported on the ocean floor in the Mariana Trench by the Swiss oceanographer Jacques Piccard, who along with pilot Don Walsh (USA) performed the first crewed dive to the Challenger Deep in the Trieste bathyscaphe on 23 January 1960.

This account of a “flatfish” (never published scientifically) was widely questioned at the time as being a misidentification, and it’s now generally believed that the creature Piccard observed was more likely to have been a holothurian (sea cucumber).

(Video) Mariana Trench | In Pursuit of the Abyss

Another more recent contender has proven more debated. In the scientific literature, it was long thought that the deepest fish was a cusk eel of the species Abyssobrotula galatheae. A specimen was reportedly collected from 8,370 m (27,460 ft) in the Puerto Rico Trench – the deepest point in the Atlantic Ocean – by the RV John Elliott Pillsbury in 1970. This is, of course, even deeper than the newly documented snailfish at 8,336 m.

Snailfish sink to new lows to extend their record as the world’s deepest fish (13)

However, the key bone of contention here is that the cusk eel was trawled and so not observed or filmed in situ at that depth. Therefore, there’s every chance it was ensnared when the net was being lowered or lifted at some point between the sea floor and the surface.

This explanation is bolstered by the fact that there have been no other sightings of these cusk eels at such extreme depths in the 50-plus years since. Furthermore, this species is reasonably well documented, and known to be more common in the ocean’s abyssal zone – i.e., 3,000–6,000 m (9,843–19,685 ft) – and typically seen swimming thousands of metres above the seafloor.

By comparison, the deepest cusk eel to have been recorded in situ are examples of Bassozetus recorded at 7,176 m (24,543 ft) in the Indian Ocean's Java Trench. This discovery too was made by Professor Jamieson, as reported in Deep Sea Research Part I in Dec 2021.

All images courtesy of: Alan Jamieson / Minderoo-UWA Deep-Sea Research Centre / Caladan Oceanic / Inkfish

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Snailfish sink to new lows to extend their record as the world’s deepest fish? ›

On 15 August 2022, a juvenile Pseudoliparis snailfish (species yet to be determined) was captured on film investigating a baited camera 8,336 m (27,349 ft) below the surface in the Izu-Ogasawara Trench off Japan. It claims the undisputed record as the world's deepest fish.

What is the deepest snailfish ever found? ›

In 2017, the Mariana snailfish was found at 8,178 metres while another undescribed species was discovered at 8,145 metres.

What is the deepest fish ever recorded? ›

Scientists exploring a marine trench near Japan were astonished to find a fish in one of the deepest parts of the ocean, at 8,336 meters (about five miles) below the surface. The tadpole-shaped, translucent creature is a type of snailfish, and it's probably the deepest fish anyone will ever find.

How do snailfish survive so deep? ›

Creatures such as giant amphipod crustaceans and the Mariana snailfish have high concentrations of organic molecules called piezolytes (the name comes from the Greek word "piezin" which means pressure), which stop their cellular membranes and proteins from being crushed under extremely high pressure.

How deep can a snailfish go? ›

Snailfish habitats vary widely. They are found in oceans worldwide, ranging from shallow intertidal zones to depths of slightly more than 8,330 m (27,330 ft). This is a wider depth range than any other family of fish. It has been found that they travel from the abyssal to the hadal zone over their lifetime.

What is the deepest creature found in the ocean? ›

It has two sets of jaws. In a hostile realm of the ocean, where the pressure is over 830 times greater than on Earth's surface, scientists spotted a fish casually swimming around. No big deal. It's a curious-looking snailfish, and at 27,349 feet (8,336 meters) down, it's the deepest fish ever observed.

What is the deepest life found in the ocean? ›

The organisms discovered in the Mariana Trench include bacteria, crustaceans, sea cucumbers, octopuses and fishes.

What fish live 1000 feet deep? ›

This species of dragonfish can grow to just under 7 inches long and can be often found 1,000 feet or more below the ocean's surface. Researchers in California recently came across an incredibly elusive type of deep-sea dragonfish nearly 1,000 feet below the ocean surface.

What fish was found at 8000 feet? ›

The two fish were later identified as the species Pseudoliparis belyaevi and are the first fish ever caught at a depth greater than 8000 metres. Some mariners may also know snailfish by their more common names -- 'sea snails' or 'lumpsuckers.

What is the biggest fish ever recorded? ›

What Was the Largest Fish Ever Caught? According to IGFA records, the largest fish ever caught was a great white shark that weighed an unbelievable 2,664 pounds (1,208.389 kg.). Caught off the coast of Ceduna, Australia, in 1959, it took angler Alfred Dean just 50 minutes to win the fight against this one-ton shark.

How do deep sea fish not get crushed? ›

Many sea creatures are made of mostly water. Water cannot be compressed, or squeezed, by pressure like air can. This means that animals in the sea can stay safe when in the depths of the sea, as their body is balanced with the pressure around them, whereas we have air in our bodies that would be crushed.

Can anything survive in the deepest part of the ocean? ›

The Mariana Trench is deeper than Mount Everest is tall and anything living there has to survive the cold water and extremely high pressure. Some animals, including the deep-sea crustaceans Hirondellea gigas , do live there —and they have recently had a human visitor.

How big can snailfish get? ›

Snailfish are tadpole-like and can only grow to about 12 inches long. They are found in oceans across the world, with some species inhabiting relatively shallow waters. The snailfish discovered 8,300 meters down — which is more than 27,000 feet, or five miles, deep — belongs to an unknown species, scientists said.

What is the biggest fish in the deep? ›

The biggest fish in the ocean is the Rhincodon typus or whale shark. Despite their tremendous size and intimidating appearance, whale sharks are commonly docile and approachable.

How deep can humans go in the ocean? ›

The maximum depth reached by anyone in a single breath is 702 feet (213.9 metres) and this record was set in 2007 by Herbert Nitsch. He also holds the record for the deepest dive without oxygen – reaching a depth of 831 feet (253.2 metres) but he sustained a brain injury as he was ascending.

What eats a snailfish? ›

Because of its deep-sea marine habitat, the snailfish does not have predators.

Is there a giant creature in the ocean? ›

The blue whale is the largest sea creature.

Is there a life Below the Ocean floor? ›

The deep-ocean floor is teeming with undiscovered life-forms that help to regulate Earth's climate, a new study finds. Researchers sequenced DNA from deep-sea sediments around the world and found that there is at least three times more life on the seafloor than there is higher up in the ocean.

How deep can life exist? ›

Life has been found at depths of 5 km in continents and 10.5 km below the ocean surface.

What is beneath the ocean floor? ›

Features of the ocean include the continental shelf, slope, and rise. The ocean floor is called the abyssal plain. Below the ocean floor, there are a few small deeper areas called ocean trenches. Features rising up from the ocean floor include seamounts, volcanic islands and the mid-oceanic ridges and rises.

What fish can walk on land? ›

Snakehead fish have evolved to “walk” on land! They propel themselves forward by moving their head and back fin in opposite directions.

What fish has no gills? ›

Unlike other fish with gills alone, lungfish can surface, take a breath and survive when other fish might be lacking air. In fact, much like many sea mammals, lungfish are obligate air breathers—they have to breathe air above water periodically to survive. A missing link?

What fish bury themselves in the sand? ›

weever, any of four species of small marine fishes of the family Trachinidae (order Perciformes). Weevers are long-bodied fishes that habitually bury themselves in the sand.

What fish was found 420 million years old? ›

Coelacanths: 'Extinct fossil fish' thought to have lived 420 million years ago found alive in Madagascar.

What fish lived 370 million years ago? ›

Ichthyostega lived between 370 to 362 million years ago. Their extinction was due to a large-scale fish extinction about 360 million years ago. This extinction event caused a reset to the evolution of life on earth.

What fish lived 400 million years ago? ›

Coelacanths, which have been around for 400 million years, were thought extinct until they were found alive in 1938 off South Africa. Scientists long believed coelacanths live about 20 years.

What is the biggest fish caught not sharks? ›

The heaviest specimen on record is a bump-head sunfish (M. alexandrini) caught off Kamogawa, Chiba, Japan, in 1996; it weighed 2,300 kg (5,070 lb) and measured 2.72 m (8 ft 11 in) in total length.

What is the biggest fish ever hooked? ›

The largest fish ever caught which is verified and listed by the IGFA is a 2,664lb (1,208kg) great white shark. It was caught by Australian angler Alfred Dean in April 1959 off the coast of Ceduna, in South Australia.

What is the strongest fish in the world? ›

It's not a shark or a killer whale... it's the Atlantic bluefin tuna— the largest and longest-lived of the 15 tuna species. Its unique set of adaptations make it one of the most dominant predators in the ocean. Grantly Galland and Raiana McKinney detail how these fish go from tiny hatchling to ocean giant.

What is the deepest fish caught on camera? ›

Check out the deepest-swimming fish ever caught on camera The unknown snailfish species, of the genus Pseudoliparis, was recorded swimming in the Izu-Ogasawara Trench near Japan at a depth of 8,336 meters — or more than 27,000 feet down.

How do whales not get crushed? ›

Whales have unique adaptations that allow them to go on long dives. They are capable of collapsing their lungs during dives to prevent damage from the increasing pressure. To further protect their collapsing lung, they have a jointed rib cage that allows their thoracic cavity to collapse with their lungs.

Can the ocean pressure crush you? ›

Too much pressure would collapse those spaces, crushing us. Animals adapted to deep-ocean life don't have air pockets in their bodies. Some marine animals travel between deep ocean and the surface.

How deep can a human go in the ocean without dying? ›

While the recommended maximum depth for conventional scuba diving is 130 feet, technical divers may work in the range of 170 feet to 350 feet, sometimes even deeper.

Can a human survive the ocean floor? ›

You can't breath at the bottom of the ocean. If you can't breath, your body won't stay alive for more than about 30 minutes. (Although you'd lose consciousness after about 5.) (3) The water pressure is very high.

Has anyone ever touched the ocean floor? ›

Thousands have climbed Mount Everest, and a handful of people have walked on the moon. But reaching the lowest part of the ocean? Only three people have ever done that, and one was a U.S. Navy submariner.

What is the largest predator fish ever? ›

The range of estimates of the maximum length for megalodon are from 17 to 20.3 m (56 to 67 ft), with a mass ranging from 65 to 114 short tons (59 to 103 t). It is also regarded as the largest macro-predatory fish ever.

What is the rarest fish in the deep? ›

Summary of the 10 Rarest and Scariest Deep Sea Creatures
1Barreleye Fish
3Sea Spider
4Pacific Footballfish
6 more rows
Apr 20, 2023

What is the biggest fish ever caught in a lake? ›

Almost 100 years ago, George Perry hooked an astonishing Largemouth Bass in Lake Montgomery, Georgia. The fish was 22 pounds and 4 ounces, good enough for a world record which still stands today.

What is the darkest deep sea fish? ›

Researchers have discovered 16 species of “Vantablack” fish. These deep-sea fish have ultra-black skin that absorbs over 99.95% of light, making them invisible to predators.

Can you dive down to see the Titanic? ›

That's right – you can dive to the depths of the ocean and see for yourself the Titanic. OceanGate Expeditions, a company made up of undersea explorers, scientists, and filmmakers offers the once-in-a-lifetime opportunity.

What depth do submarines cruise at? ›

Now, the operating depth of most modern submarines is 300 to 450 meters. For a submarine to surface from that depth, it first uses its hydroplanes to reduce its depth upto 3 to 4 meters below waterline.

Can you survive 47 meters in the ocean? ›

According to the US Navy dive decompression tables a diver may spend up to five minutes at 160' (47 meters) without needing to decompress during their ascent. The longer a diver stays underwater the greater their exposure to “the bends” becomes.

What is a fact about snail fish? ›

The Mariana snailfish, as they've dubbed the species, has a translucent body reaching a length of over four inches, and looks somewhat like a overgrown tadpole. The Mariana snailfish feed on crustaceans, which are plentiful in the deep sea; many snailfish specimens brought back to the surface had a full stomach.

What eats dead fish at the bottom of the ocean? ›

Time-lapse footage shows how fast sea stars move onto a dead fish to eat it.

What do most animals who live deep in the ocean eat? ›

Deep sea creatures have evolved some fascinating feeding mechanisms because food is scarce in these zones. In the absence of photosynthesis, most food consists of detritus — the decaying remains of microbes, algae, plants and animals from the upper zones of the ocean — and other organisms in the deep.

How deep is the hadal snailfish found? ›

We wanted to find this elusive winged snailfish again to learn more about it and observe it in its natural habitat. These hadal snailfish tend to live at depths between 7,000 and 8,200 metres (“hadal” simply means anywhere below 6,000 metres), but their apparent rarity is perhaps misunderstood.

Has anyone been to the hadal zone? ›

Only three people in history have seen them in person. Marine biologists hope to save these depths from destruction before it is too late.

What is the deepest fish scientists land ever? ›

The snailfish, of the Pseudoliparis belyaevi species, are the first to be caught below 8,000 metres. Fish have been caught more than 5 miles (8 kilometres) under the surface of the ocean for the first time ever - and filmed even deeper - by a joint Japanese-Australian scientific expedition.

What are the scary looking fish at the bottom of the ocean? ›

Commonly known as “Sea Devils,” Anglerfish are the archetypal horror of the deep. They lurk on the bottom, waiting for unsuspecting prey to come their way. Their mouths are so big they can eat fish almost as big as they are. Anglerfish inhale their meals whole.


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