The world’s largest invertebrate remained hidden from humans until it was first seen 100 years ago. However, it took us decades to see this giant squid with our own eyes.
Beneath the dark light of a mausoleum in New Zealand’s Te Papa Tongarewa museum, a monster lies in state. Its massive body lies in a large glass coffin, thick tentacles extending from beneath a strange, spotted body that once contained two large, staring eyes.
Among the animals that inhabit New Zealand waters, it seems like a creature from another world – reminiscent of the first awe-inspiring description of a Martian, given by the unnamed narrator in H.G. Wells’s War of the Worlds . Clusters of tentacles beneath a bear-like bulk and a nightmarish beak.
But this was no interplanetary visitor, but something from the pitch-black cosmos within us: a giant squid . It is the largest invertebrate on Earth, and the rare specimen on display at Te Papa , the Maori name by which the museum is better known, is the first of its kind. This hidden creature has been found alive – for only a brief time – in human history.
For an animal of its enormous size, the giant squid has an extraordinary ability to hide from human sight. Its discovery was a gradual process, with signs of its existence persisting for decades. And then – almost exactly 100 years ago – we first saw these almost mythical creatures.
To date, there have been no recorded sightings of a giant squid in its natural habitat, although there have been a few unconfirmed sightings. In June 2024, scientists on an Antarctic expedition announced that they may have captured one using a camera mounted on a polar cruise ship in 2023. Brief footage suggests it may be a juvenile giant squid in the cold waters near Antarctica , but the footage is still being closely studied by other scientists. The fact that they can’t be sure highlights just how lonely and mysterious this giant squid is.
Because this animal lives at such depths in the ocean that modern humans have only recently visited, the first clues to its existence are the remains sometimes found in the stomachs of whales. hunting them. The half-digested fragments hint at a giant, bizarre squid whose limbs end in clubs with sharp hooks capable of grabbing and causing terrifying battle scenes to survive on the ocean floor while battling whales.
Unknown giants of the deep
The giant squid’s elusiveness highlights how little we know about the ocean’s depths. And there may be other large sea creatures waiting to be discovered in some of the least explored depths.
There are thought to be up to two million species in the oceans, with some estimates putting the number even higher. According to the World Register of Marine Species, fewer than 250,000 species are currently known.
For more information on the giant creatures that are likely waiting to be discovered on the ocean floor, read this article by Marta Enriquez .
Then, in 1981, the Soviet fishing vessel Eureka caught a giant squid in its nets while fishing in the Ross Sea off Antarctica. The discovery went largely unnoticed until the end of the Cold War a decade later. In 2000, Soviet scientist Alexander Remeslo wrote about the incident on The Octopus News Magazine Online forum , giving a first-hand account of how the animal was caught.
“Early in the morning of February 3, 1981, I was working in the Lazarev Sea near Queen Maud Island in Antarctica,” he wrote. “A fellow scientist burst into my cabin and poked me in the ribs, shouting, ‘Wake up, we’ve caught a giant squid!’ With a camera around my neck, I ran up to the deck. There lay a giant reddish-brown squid. None of the crew, some of whom were vagrants who had gone over the seven seas, had seen anything like it before.”
Craft’s story paints a dramatic picture: heavy snow was falling on the deck, and the light was so weak that he had difficulty getting a properly exposed photograph of the squid, which had been pulled from the net and was lying motionless in front of him.
“Eager to see the results of my photography, I decided to develop the film on board rather than store it for development in a professional lab at home,” said Remeslo, now a research fellow at the Atlantic Oceanography and Marine Fisheries Research Institute in Kaliningrad, Russia, in his report. “The quality of the photographs taken that day was not as good as expected. But the most important thing was still achieved — what was probably the world’s first large specimen of a giant squid ( Mesonychoteuthis hamiltoni ) recovered from the deck of a ship, rather than taken from the stomach of a sperm whale!”
I was so eager to see the results of my photography that I decided to develop the film on the train – Alexander Remeslo
A black-and-white photograph taken by Remeslo and included with his article shows two crew members from the Soviet ship crouched next to the dead squid. The creature’s two long arms, clenched like fists, are visible in front. According to Remeslo, the squid was 5.1 m (16.7 ft) long, with the shell alone exceeding 2 m (6.6 ft). The squid is described as a young female, not yet fully grown.
It took more than 20 years for another juvenile giant squid to be found. This time, in 2003, it captured the world’s attention. ” Super squid found in Antarctica ,” BBC News reported at the time. The dead squid was found floating on the surface of the Ross Sea off the coast of Antarctica and hauled onto a fishing vessel.
The animal’s body was flown to Wellington, New Zealand, where two scientists, Steve O’Shea and Kat Bolstad of the Auckland University of Technology , reassembled the creature and examined it. This made O’Shea an internationally recognized expert on giant squid.
“We were sitting in Te Papa, and I had this huge thing sitting on a slab of rock,” said O’Shea, who now lives in Paris. “It had completely defrosted. I called a couple of people and said, ‘Listen, I’ve got a giant squid sitting on a rock in my office. Do you want to come and see it?’
O’Shea was so excited he didn’t notice the date: April 1, 2003. Everyone took it for an elaborate joke. “Nobody takes me seriously,” he said. “It wasn’t until we sent them a photo of what we were working on on the stove that the press started paying attention… my phone didn’t stop ringing for a month.”
Even for someone like O’Shea, who is familiar with large cephalopods, the giant squid was an impressive sight. “I’d never seen anything like it before,” he said. “I’d worked a lot with a guy called Malcolm Clarke on a couple of my documentaries before, and he’d spent his life studying the stomach contents of sperm whales, and he’d reported seeing beaks in sperm whale stomachs on numerous occasions. I knew the giant squid existed. I couldn’t imagine it looking anything like what we were seeing in front of us.”
The giant squid kind of bored me because it was just a big, boring squid – Steve O’Shea
O’Shea had previously studied another large squid species , the giant squid Architeuthis dux , which can grow up to 13 m (43 ft) long . In 2003, he encountered a completely different species.
“The giant squid seemed kind of boring to me because it was just a big, boring squid,” he said. “It didn’t have any really attractive features other than its size. And here I was dealing with something that had rotating hooks on its arms and a beak… much bigger and much stronger.”
The giant squid is thought to weigh over half a ton (500 kg). Although the giant squid’s tentacles are much longer than those of the giant squid, the giant squid’s shell is larger and heavier.
But this giant squid is more than just a squid that can transform into a larger-than-normal size. Its eyes, which can reach 11 inches (27.5 cm) in diameter , are the largest ever found in an animal . Its beak, made of protein similar to that found in human hair and fingernails, is a sharp, clawed mouth that can tear apart prey. Another organ called the radula, which has many sharp teeth, can tear chunks of meat into smaller pieces.
The squid has hooks protruding from its arms. Other squid, including the giant squid, have teeth inside their suckers. The giant squid has something even more amazing – the curved hooks that the squid uses to cling to its prey. Incredibly, the hooks on its sucker-like tentacles can rotate 360 degrees . Scientists don’t yet know whether the squid can rotate these hooks at will or if they move on their own once they are attached to prey.
O’Shea used the discovery of the squid and the subsequent media coverage as a platform to attack New Zealand’s fishing industry and what he called some of its destructive activities. That industry is in the Southern Ocean . He says there was some resistance to his involvement when an even larger squid (the one on display at Te Papa) was found a few years later. However, amid all the noise, O’Shea eventually gave Mesonychoteuthis hamiltoni its accepted name: the giant squid.
Two years after O’Shea landed a giant squid on his rock, a fisherman almost landed a live specimen. In 2005, a Patagonian toothfish fishing boat near South Georgia Island in the South Atlantic caught a giant squid on one of its lines . Five fishermen struggled to get the squid onto their boat, but were unsuccessful. The footage of its movements in the water is believed to be the first ever recorded of a live giant squid.
While editing this article, I was reminded of another article we published in 2023 about how deep-sea creatures can survive the terrifying depths they inhabit. They have a variety of anatomical and cellular adaptations that help them withstand the intense pressure the water exerts on their bodies. You can read more about this in Isabel Gerretsen’s article .
The author of this paper, my colleague Stephen Dowling, has also previously conducted extensive research on several newly discovered species of deep-sea sharks .
In February 2007, the New Zealand fishing vessel San Aspiring , also fishing for Patagonian cod in the Ross Sea near Antarctica, pulled in a line. Between them was a giant squid, fully grown and still alive .
The squid’s decision to try and grab a quick bite backfired. “It decided to eat a toothfish off a long line, got caught on the spine and part of the line and was dragged to the surface,” Andrew Stewart, Te Papa’s fish curator and one of the world’s most respected fish scientists, said. The animal is estimated to have weighed up to 450 kilograms (990 pounds) and was about 10 meters (30 feet) long . Some of the vessel’s fishing gear had left deep cuts in the squid’s body, and it was seriously injured and would likely die if returned to the ocean.
Ships like the San Aspiring carry New Zealand fisheries scientists on expeditions, partly in case they come across new or rare species. “They looked at this thing right on the surface, right at the edge of the boat, and they realised that because it had a damaged spine on the rail, no, it wasn’t going to be able to get out on its own,” Stewart said. “It was very difficult to get on board because you’re dealing with this very soft specimen. How do you get it from the side of the ship to the deck, and then what do you do with it?”
A giant squid of this size, relatively intact and still alive when it surfaces, certainly meets the scientists’ criteria for something worth preserving. But then they face the problem of how to keep it cold and whole while they go fishing.
They just put this half-tonne thing in a cubic metre and freeze it, turning it into a giant squid ice cream cone – Andrew Stewart
“They took it below deck and froze it in what’s called a pelican box,” said Stewart, who was the first to receive the call from the fisheries watch program that a giant squid had been caught. He was arrested. “These are one-cubic-meter (35-cubic-foot) tanks of fuel and stuff like that. And when they reach the edge of the Southern Ocean, they take them below deck. They dump them and clean them. The top part is cut off. They’re used to store scientific specimens and organs. So they just put this half-ton thing in this cubic meter and freeze it into a giant squid ice cream cone. giant
When the San Aspiring finally returned to Wellington, unloading was relatively easy, Stewart said. “All you have to do is back the forklift up to the trolley and move it,” he said. Once it arrived, it was taken straight to the Te Papa freezer station.
“We were scratching our heads, wondering, ‘How do we fix this?'” Stewart said.
Even thawing a frozen specimen of this size is a challenge, let alone preserving it. “The way these things are made and the chemical composition of them means they can rot on the outside and the inside stays frozen,” explains Stewart. “So they built a huge wooden tank, lined with three layers of rubber cement, then three layers of heavy-duty polyethylene.
“Stephen [O’Shea] and his colleagues came up with the idea that if we make the brine very cold, it will slow down the rate of thawing.” This gives the scientists much better control over the thawing process.
“If you freeze something, the ice expands and breaks down the connective tissue, causing it to become more gelatinous,” O’Shea adds. “When we thaw this thing, of course, the ice crystals expand and everything explodes. Then, when the ice melts, everything shrinks. When it’s on the stove, thawing, we can see it lose mass.”
According to O’Shea, to preserve the body, its tissues need to be treated with a formalin solution, but it’s crucial to do it correctly. “As I recall, it was 4% formalin. After I fixed it inside and out, we submerged it in a vat of formaldehyde/seawater. And then we had to monitor the thing for 48 hours. For the next 72 hours, monitor the pH, because once the pH goes above 7, the calcium hooks line up into tentacles and the suckers start to dissolve.”
When the pH of the solution becomes too acidic, the tank is drained and more formalin solution is added. “It retains the color,” O’Shea said. “It’s a beautiful specimen.”
How do we store it, how do we display it, and how can we extract it for further use? – Andrew Stewart
Te Papa knew the squid could be the star attraction. But the giant thawed body created a whole new problem, Stewart said. “First, how are we going to display it? And second, how are we going to transport this big, soft thing?”
The giant squid is adapted to life under the enormous pressures of the deep ocean, meaning its soft body is supported by the surrounding water. Outside, it would collapse.
“If you’re not careful, it can all fall apart,” Stewart said.
Te Papa’s solution was to turn to a glass company in nearby Palmerston North, which made a specially curved squid box using technology that did not create bubbles during the manufacturing process.
The box was assembled right next to where the defrosted squid was stored in central Wellington, about 900 metres (984 yards) from the museum. Museum experts then had to decide how to preserve and transport it. “What do we store it in, what do we display it in and how do we get it out of here and out on the street?” said Stewart. “We can’t display it in alcohol or formalin because of health and safety issues, fire risk management and all that stuff.” Another member of the team suggested soaking the squid in polypropylene glycol. While Stewart says it’s non-toxic, “they have to put a fairly toxic biocide in there to stop any bacterial and fungal activity.”
As the team struggled to figure out how to move their giant carcass, something elemental came to their aid: gravity. Wellington is a hilly city, and the squid was at the top of a slope. They came up with a plan: the squid would be delivered to the museum late at night on a flatbed truck in a container, but to reduce the weight, all the liquid would have to be removed. “It only glides down late at night when there’s no traffic and the traffic lights can be set [to let it through].” The squid would then be safely unloaded and taken up residence in Te Papa, a messenger from the abyss that only a few people ever get to see.
“Some people say, ‘Oh, it looks a bit rough and brittle, but it’s no worse than when it came out of the formaldehyde,'” says Stewart. “The poor thing was pretty damaged when they hauled it on board the boat.
“It’s going to slowly decompose, you can’t stop it. It’s going to be affected by light, temperature fluctuations… it’s going to decompose. It’s a bit like Frankenstein’s monster, with the stitches holding it all together,” Stewart said. “Peter Jackson [the film’s director] made some notes.”
Specimens like the one found at Te Papa provide important clues about the biology and behaviour of this enigmatic deep-sea mollusk. Giant squid recovered so far almost always come from deep waters. They either become entangled in cables or attack fish caught in nets, lured by the prospect of an easy meal. Their interactions with humans are involuntary, often aggressive and extremely brief.
Scientists have been able to piece together the life cycle and habits of the giant squid. However, many mysteries remain. It’s like trying to create a coherent story about someone’s life using a few vacation snapshots, most of which are out of frame.
Giant squid are remarkably well-adapted to surviving in cold, dark conditions, and live at the top of the food chain in the frigid waters they call home. They prey on large sub-Antarctic fish such as the Patagonian toothfish (also known as the Chilean grouper) – dozens of which were caught by fishing vessels between 2011 and 2014 all had distinctive tail injuries. The squid have a hook, like the squid of the Centre for Environment, Fisheries and Aquaculture Science in the UK , according to Vladimir Laptikhovsky . “Given the size of the adult squid, toothfish are probably its most common prey species, as there are no other deep-sea fish of similar size in Antarctica,” he told New Scientist in 2015. However, there are some reports of juvenile giant squid, which live closer to the surface, being eaten by penguins and other seabirds .
A 2010 study by the University of South Florida found that the giant squid only needs to eat 30 grams (1 ounce) of food per day.
Few animals are thought to prey on giant squid, with the exception of sperm whales and southern sleeper sharks, slow but powerful deep-sea sharks that can grow up to 4.2 m (14 ft) long. The giant squid’s size is a defensive adaptation: the bigger you are, the less likely you are to be eaten by another species.
And this development is happening rapidly. Like the giant squid, colossal squid are not thought to live longer than five years , although their exact lifespan—like that of many other such creatures— remains largely a mystery . They appear to live longer than smaller squid species (most live just over a year ), but significantly shorter lives for their large size. This type of growth is called abyssal gigantism, and it is seen in many other cold-water, deep-sea species, including spider crabs.
This gigantism, surprisingly, does not require a huge amount of energy. A 2010 study at the University of South Florida found that a giant squid can survive for about 160 days on just one 5 kg (11 lb) toothfish, equivalent to just 30 g (1 oz) of food per day , or just 45 calories. Temperatures in the deep Southern Ocean where they live typically hover around 1.5 °C (34.7 °F), and research shows that the larger the animals in these conditions, the lower their metabolism, making them more efficient . Studies of giant squid metabolism show that they have a slow pace of life, spending much of their time passively drifting, waiting to ambush prey.
The giant squid’s large eyes are thought to have evolved to detect large predators such as sperm whales, rather than to spot prey from a distance.
Juveniles are thought to live closer to the surface, at depths of over 500 m (1,640 ft), but as they grow they descend to depths of up to 2,000 m (6,560 ft).
Much of the squid’s life cycle remains hidden. One of Te Papa’s staff has attempted to fill in the gaps in the squid’s life and written a book about it. Wheetie: Giant Squid of the Deep , a children’s book written by Victoria Clayle and released in 2020, tells the life story of the giant squid, from hatching from a tiny egg to becoming the world’s largest invertebrate (illustrations by Isobel Joy Te Aho-White)
Clal said she was chosen to write the book because of her experience writing labels for children’s exhibits, which helps keep them as friendly and informal as possible. “They know that kids have a strong desire to learn about giant squid, whether it’s in books, on exhibit labels, or in videos,” she said. “It’s a constant draw. Everyone who comes to the museum wants to see a giant squid.
“There are kids now who have seen this movie from the beginning and are watching it again as adults… and I love the idea that one day they will be able to take their kids to see it again.”
Despite the efforts made to display the squid, the years had taken their toll. “This squid is no longer beautiful,” said Clayle. “The eyes and other body parts had been removed, there were a lot of stitches. I wanted to mention this squid in the book, just to make a connection between the book and Te Papa. But this squid had a very unhappy end because it got tangled in a rope and died.”
By telling the story of another species of squid that still roams the cold-water world off the coast of Antarctica, Cleel can imagine its entire life cycle, even if much remains unknown.
I just think it’s great for kids to be advocates for science as a career, to realize that there’s so much out there to explore – Victoria Cleel
With the help of ink experts like Kat Bolstad, Cleel set to work. It’s impossible to include a male squid in the story, since none have ever been seen. “But there are things we can imagine, like what it’s like to be 2,000 metres (6,561 feet) down, even if no one has ever been down there, in the Ross Sea.” It’s all about keeping whiti (a Maori word meaning change or remake) within reach, she says.
Kleil said the squid’s enormous size and intimidating appearance are part of the appeal to younger audiences, but ultimately the underwater “monster” is relatively harmless. Many descriptions of giant squid evoke the mythical sea monster Kraken that terrorized ancient mariners, but in reality, the creatures live so deep and so far from shore that people are unlikely to encounter one in the water. But the fact that we know so little about giant squid and the world they inhabit makes them all the more intriguing, Kleil said. “It’s a mysterious world, I think, that captures people’s imaginations. We don’t know what’s going on out there.”
Clal said the idea for the giant squid story came partly from a desire to encourage children to imagine what other creatures might live in the cold, dark depths that squid call home. “I just think it’s great for kids to be an advocate for science as a career, to think that there are things out there to be discovered. What hasn’t been discovered yet? And why wouldn’t you? Why not try to be a marine biologist?
James Eric Hamilton was a marine biologist, naturalist and oceanographer who spent much of his life on the Falkland Islands and nearby islands. He arrived in 1919 to conduct a survey of the fur seal population. A few years later, he became the Falkland Islands administrator and spent much of the 1920s working on whaling ships or at stations supporting them on the South Atlantic islands.
Hamilton regularly examined the stomach contents of whales as part of his work, and in the winter of 1924/25 he discovered something in the stomach of a sperm whale that he had never seen before: the tentacles of a large, mysterious squid with sharp pincers.
Hamilton believed that this was a new species to science. He preserved them and then sent them to the Zoological Department of the British Museum in London.
Soon after, a report appeared in Natural History magazine that the creature’s limbs were “equipped with a group of four to nine large hooks” and that its hands were “made up of hooks only, capable of rotation in any direction.” Hamilton’s specimens are the first scientifically documented remains of a giant squid. The species, first described by Guy Coburn Robson in 1925, would be named in his honor. Hamilton died in 1957, decades before a complete giant squid was discovered.
There, in a jar labeled “Mesonychoteuthis Hamilton, 1925,” lay the remains of the squid that had so fascinated Hamilton a century earlier.
When I spoke to O’Shea, I mentioned the tentacles that Hamilton had discovered a century earlier. His response was immediate: “Have you seen them?” It turns out that the original tentacles that identified the species still sit, suspended in a jar, on the shelves of the mollusc department at the Natural History Museum in London . A few days later, O’Shea received an email from his friend John Ablett, the museum’s senior curator of molluscs, inviting him to come and see them.
A few weeks later, he took me through the museum’s seemingly endless corridors. The proverb is like finding a needle in a haystack. “We have eight million objects in the shellfish department alone,” Ablett says happily.
These vaults contain dozens of jars, each containing a species of animal (or part of a species of animal) that was once new to science. Ablett found the right door and opened it. There, in a jar labeled “Mesonychoteuthis Hamilton, 1925 ,” were the remains of the squid that had so intrigued Hamilton a century earlier. The first scientific evidence of giants lurking beneath the deep seas.
“The weird thing is, we don’t really know much about how the specimens were found and recovered,” says Ablett. “The way the specimens were collected at the time was hardly considered important. And of course, you don’t know what’s important until you realise it’s important.”
The whale is thought to have been taken from the Falkland Islands and the tentacles sent to what was then the British Museum. Robson examined them on arrival.
“The way animals are preserved hasn’t really changed in the last 200 years,” says Ablett, noting that alcohol is still sometimes used. “With many invertebrates, particularly deep-sea creatures, preservation techniques can actually distort features and often reduce them.” The century-old tentacles look lumpy and oddly coloured, but the spinning pincers that so fascinated Hamilton are still there.
“You know, it’s a half-chewed part of the stomach… basically a ring of flesh around the mouth, most of the arm, and that’s it,” Ablett said. “But he [Hamilton] was able to work out that they were so different from all other known squid that they needed to be classified as a new species. And I think sperm whales are really good at catching things in the ocean at depth, much better than we were then, and maybe even now.”
The giant squid remains predate molecular classification, and further study of this centuries-old squid could reveal more about its life. Ablett said scientists know for sure that the giant squid and the colossal squid are completely different animals . “They are not closely related,” he said.
The giant squid raises some interesting questions about why some squid species grow so big while others remain relatively small, Ablett says. “What’s always fascinated me is that a lot of the giant squid’s relatives – the crank squids, or glass squids – are really, really small, you know, a few inches long. But this is the only one that’s that big. So.”
One of the advantages of being big, of course, is that no one can eat you – John Ablett
Ablett says a century after the first giant squid was discovered, we still know very little about them. In 20 years of studying the elusive giant squid, he says, “they haven’t turned up in large enough numbers.” “They have yet to be observed in the wild, in their natural state.”
Ablett says there are clues in biology about how squid might survive in the deep, cold waters of the Southern Ocean. “Look at the giant squid, it’s very ungainly. It doesn’t look very sleek.” He thinks this may have underlined its status as an ambush predator. “Is it lurking in these dark oceans, waiting for this to pass?” he asks.
Ablett said scientists had found that where giant squid live, there are no giant squid. The corresponding large mammals of the cephalopod world seem to have drawn some invisible line in the world’s oceans that none of them have crossed. And very cold oceans are a favourite habitat for very large creatures, he said. “There seems to be a tendency for creatures, particularly in the polar regions, to get very, very big. I mean, one of the advantages of getting bigger is, of course, that there’s nothing to eat you?”
The centuries-old tentacles preserved in the museum’s jars aren’t the only giant squid relics in the museum. Hidden away in the basement is a room filled with jars and tanks containing all sorts of strange creatures (you’ll see this if you’ve seen the Tom Cruise version of The Mummy). A pristine Komodo dragon, a deceased former resident of London Zoo, floats in a large tank. The heads of deep-sea sharks have bared their fangs from inside large jars.
Other jars contained larger remains of giant squid. Ablett even released some of them from the tank for photographs, the preserved flesh glistening under the light as he held them up to the camera.
In another tank—a very, very large one—the remains of another giant squid are preserved in a solution. The entire giant squid takes up most of the tank, its long tentacles extending far beyond the spotted surface. One can imagine a long line of tourists waiting to pass through, but this room is not open to the public. The tank would have to be made by professionals who often do installation art. If the museum is lucky enough to get a whole giant squid, they might have to build another one. At least the two squids can meet in death.
In the meantime, scientists will continue to gather all the information they can about the world’s largest invertebrate. But it also raises the question of what else might be lurking in the depths, still waiting to be discovered.
“Most species discoveries tend to be minor because these are the things we miss,” says Ablett. “But I’d be lying if I said I wasn’t hopeful that there’s something even bigger than the giant squid. I mean, what would we call it?”
