Animal
Colossal squid
The colossal squid is a huge, heavy squid that lives in the cold, deep sea around Antarctica. It has hooks on its arms and enormous eyes.
The colossal squid lives deep in the icy Southern Ocean around Antarctica. It is thought to be the heaviest animal without a backbone: one caught in 2007 weighed about 470 kilograms. Its arms and tentacles carry sharp, turning hooks, and in 2025 scientists filmed a living one in the wild for the first time.
Mesonychoteuthis hamiltoni, described in 1925 from arm crowns found in a sperm whale's stomach, is known from very few specimens: Te Papa counts nine above juvenile size. The most complete large specimen, caught in 2007, has a 2.5-meter mantle and weighed about 470 kilograms. Its first footage alive in its habitat, a 30-centimeter juvenile, was recorded in 2025.
Photo: Scotted400, CC BY-SA 4.0, via Wikimedia Commons
Meet the colossal squid
The colossal squid is a very big, heavy squid.
It lives in the cold, dark sea near Antarctica. Its arms have hooks that can turn, and it has huge eyes.
The colossal squid is a deep-sea squid from the Southern Ocean around Antarctica. Its arms are shorter than a giant squid's, but its body is wide and heavy. It is thought to be the heaviest invertebrate, or animal without a backbone, on Earth.
Scientists have found very few of them. The colossal squid was first named in 1925 from pieces found inside a sperm whale's stomach. Since then, only a handful of large ones have been found, some in sperm whale stomachs and some brought up by fishing boats.
Mesonychoteuthis hamiltoni (family Cranchiidae) was described in 1925 from two arm crowns recovered from a sperm whale stomach at the Falkland Islands. Its biology remains poorly known: Te Papa reports that only nine specimens above juvenile size have been recorded since then.
It belongs to a different family from the giant squid. Te Papa describes it as reputed to grow heavier than Architeuthis, with the largest beaks known of any squid, and the 2025 Ocean Census release calls it the heaviest invertebrate on the planet. Size estimates for the biggest individuals rest on beaks from sperm whale stomachs rather than on whole animals, so they remain estimates.
Quick facts
- Group
- Invertebrate
- Length
- up to 2.5 m
- Weight
- 470 to 495 kg
Where it lives
Colossal squids live in the icy sea around Antarctica.
The water there is very cold, and the grown-ups live very deep.
Colossal squids live in the Southern Ocean, the cold sea that surrounds Antarctica. The water where adults live is close to freezing, more than 1,000 meters down.
Young colossal squids live higher up, from near the surface down to about 1,000 meters. In 2025, a young one was filmed 600 meters deep near the South Sandwich Islands in the South Atlantic.
Te Papa describes the species as cosmopolitan in sub-Antarctic to Antarctic waters, with adults living at depths beyond 1,000 meters in near-freezing water and juveniles not uncommon from surface waters to about 1,000 meters. The IUCN assessment lists Antarctica, Argentina, Australia, Chile, the Falkland Islands, South Africa and South Georgia and the South Sandwich Islands, at depths of 20 to 2,000 meters.
Records outside Antarctic waters need caution. Te Papa notes beaks from sperm whales off California and from wandering albatross chicks, but both predators travel long distances, so such beaks do not prove the squid lives where they were found.
Its habitats
Where can you find this animal?
- Lives here naturally · Countries and seas named by a scientific source
- Sightings recorded · Records of wild sightings (GBIF)
Lives here naturally · Countries and seas named by a scientific source
Deep sub-Antarctic and Antarctic waters of the Southern Ocean; adults mostly below 1,000 meters, young higher up. The IUCN also lists waters off southern South America, South Africa and Australia. Beaks found farther north in sperm whales and albatrosses do not prove the squid lives there.
Places: Southern Ocean.
Source: https://collections.tepapa.govt.nz/topic/588 · checked October 2026
Sightings recorded · Records of wild sightings (GBIF)
Counts of GBIF records of wild observations (human and machine) and preserved specimens. Records include introduced populations, vagrants, escaped or released animals and misidentifications, so a country with records is not necessarily part of the native range.
Wild sightings have been recorded in Antarctica, Australia, Fr. Southern Lands, United States, Argentina, DR Congo, Chile, Indonesia and 8 more places.
Source: gbif · checked October 2026
Range maps show where scientists say an animal lives, often country by country. An animal may live in only part of a country shown, and sightings records can include animals that wandered far from home.
What it eats
Colossal squids eat fish in the deep sea.
Fishing crews have seen them grab big fish called toothfish.
Scientists have never watched a colossal squid hunt in the wild, so they know little about what it eats. But fishing crews in the Antarctic have caught colossal squids holding on to toothfish, large fish that the boats catch on long lines.
In 2007, a colossal squid grabbed a toothfish on a fishing line 1,500 meters down and would not let go as the line was pulled up. That is how the most complete colossal squid ever found came to the surface.
Te Papa's collection notes state that its life history, diet and behavior are essentially unknown because its environment has been so poorly sampled. What is known comes from fisheries: Kat Bolstad of Auckland University of Technology describes the species as encountered mainly as prey remains in whale and seabird stomachs and as a predator of harvested toothfish.
The 2007 specimen attacked an Antarctic toothfish (Dissostichus mawsoni) on a longline at 1,500 meters and held on as the line was hauled up.
Did you know?
A squid in a museum tank can shrink!
The 2007 colossal squid was first thought to be 8 to 10 meters long, but it measured only 4.2 meters once it was thawed, because its tentacles had shrunk.
In Te Papa tests on arrow squid, fresh specimens shrank by up to 22 percent when dehydrated in alcohol; the chitin beak does not shrink, so its lower rostral length is used to estimate size.
Hooks, beaks and big eyes
The colossal squid has hooks on its arms and tentacles.
The hooks can turn, like little swivels. Its eyes are some of the biggest of any animal.
What makes the colossal squid special is its hooks. The ends of its two tentacles carry two rows of sharp hooks that can swivel, and its eight shorter arms have both hooks and suckers. Its beak, a hard mouthpart, is the largest of any squid.
Its eyes are among the largest in the animal kingdom. The photo shows the colossal squid on display at Te Papa, the national museum of New Zealand. It is preserved in a long tank, and preserving it has changed its shape and size.
Te Papa lists its unique characters: the tentacle club bears two rows of swiveling hooks, the relatively short arms carry both hooks and suckers, and the beaks are the largest known of any squid, larger and more robust than those of Architeuthis. Nilsson and colleagues (2012) note that giant and colossal squid have the largest eyes in the animal kingdom and suggest these huge eyes may have evolved to detect very large predators such as sperm whales.
Measurements change after death. The 2007 specimen was estimated at 8 to 10 meters before thawing but measured 4.2 meters total, its tentacles having shrunk. In tests on arrow squid, Te Papa staff found that fresh squid can shrink by up to 22 percent when dried out in alcohol, while the hard beak does not shrink.
Growing up
Baby colossal squids are see-through, like glass.
They live higher up in the sea. As they grow bigger, they lose their see-through look.
Very little is known about how colossal squids grow up. In 2025, scientists using a deep-sea robot filmed a young one about 30 centimeters long. It was see-through, almost like glass. Colossal squids lose that see-through look as they grow.
A grown-up female can make thousands of eggs, each only about 3 millimeters across. No one has yet seen a colossal squid lay its eggs.
Ocean Census reports that little is known of the life cycle, but that juveniles are translucent and lose this appearance as they grow; the 2025 juvenile, filmed by the ROV SuBastian from R/V Falkor (too) at 600 meters near the South Sandwich Islands, was about 30 centimeters long. Te Papa's collection notes give 6,000 to 8,000 eggs, up to 3 millimeters across, in mature females, and large nidamental glands that suggest eggs are released in gelatinous masses.
Mating is not well understood. The species lacks a hectocotylus, and Te Papa suggests males may implant spermatophores directly, as proposed for a related cranchiid squid.
Seen alive at last
For a hundred years, nobody saw a colossal squid alive in the deep sea.
Then, in 2025, a robot camera filmed a baby one swimming. Hello, little squid!
For about a hundred years after it was named, scientists knew the colossal squid only from dead or dying animals, mostly from fishing boats and whale stomachs. Then, in 2025, a team exploring the deep sea near the South Sandwich Islands filmed a young colossal squid gliding through the water 600 meters down, using a remote-controlled robot.
It was the first time anyone had filmed one alive in its natural home. Experts checked the video carefully before announcing it.
The 2025 sighting came during the Ocean Census GoSouth expedition, a collaboration of The Nippon Foundation-Nekton Ocean Census, Schmidt Ocean Institute and partners, on the hundredth anniversary of the species' description. Independent experts, including Kat Bolstad, verified the footage. Dying adults had previously been filmed by fishers, but none had been seen alive at depth.
Sperm whales are a known predator, and scientists consider the colossal squid a major prey of sperm whales in the Southern Ocean. Te Papa reports that colossal squid beaks make up about 14 percent of beaks found in sperm whale stomachs from the Antarctic and, because of the squid's size, an estimated 77 percent of the biomass consumed.
Did you know?
Scientists first learned about colossal squids from pieces found inside a whale.
The colossal squid was first named in 1925 from two sets of arms found in a sperm whale's stomach.
The species was described in 1925 from two arm crowns recovered from a sperm whale at the Falkland Islands; they are held at the Natural History Museum in London.
Learning about a deep-sea giant
Colossal squids are not known to be in danger.
They live so far away and so deep that scientists are still learning about them.
The IUCN Red List lists the colossal squid as Least Concern. But the check was done in 2010, it needs updating, and nobody knows how many colossal squids there are.
Some colossal squids are caught by accident by boats fishing for toothfish. When that happens, crews in New Zealand have handed the squids to scientists, and Te Papa now has three large specimens to study.
The IUCN assessed Mesonychoteuthis hamiltoni as Least Concern (assessed 2010, published 2014, flagged as needing an update), with an unknown population trend and no listed threats. Nearly everything known comes from toothfish longline catches and from remains in sperm whale and seabird stomachs (Kat Bolstad, quoted by Ocean Census).
Te Papa holds three large specimens, caught in 2003, 2007 and 2014 by New Zealand longline vessels in Antarctic waters. The 2014 examination was webcast to more than 800,000 viewers from over 180 countries. Scientists at Auckland University of Technology have been redescribing the species' anatomy across its lifespan from these specimens.
IUCN Red List
How is the colossal squid doing in the wild?
- Least Concern (this animal)
- Near Threatened
- Vulnerable
- Endangered
- Critically Endangered
- Extinct in the Wild
- Extinct
Least Concern
Not at risk of disappearing from the wild right now.
Amazing facts
-
The colossal squid's hooks can turn around, like swivels.
The tips of a colossal squid's tentacles carry two rows of hooks that can swivel.
Swiveling hooks on the tentacle clubs, and hooks plus suckers on the arms, are diagnostic characters (Te Papa).
-
Scientists first learned about colossal squids from pieces found inside a whale.
The colossal squid was first named in 1925 from two sets of arms found in a sperm whale's stomach.
The species was described in 1925 from two arm crowns recovered from a sperm whale at the Falkland Islands; they are held at the Natural History Museum in London.
-
Baby colossal squids are see-through, like glass.
The young colossal squid filmed in 2025 was see-through and about 30 centimeters long.
Juveniles are translucent and lose this appearance with growth; the 2025 individual was about 30 centimeters long.
-
A squid in a museum tank can shrink!
The 2007 colossal squid was first thought to be 8 to 10 meters long, but it measured only 4.2 meters once it was thawed, because its tentacles had shrunk.
In Te Papa tests on arrow squid, fresh specimens shrank by up to 22 percent when dehydrated in alcohol; the chitin beak does not shrink, so its lower rostral length is used to estimate size.
Words to know
- invertebrate
- an animal without a backbone
- mantle
- the main part of a squid's body
- beak
- the hard, sharp mouthpart of a squid or octopus
- specimen
- an animal or part of one collected for scientists to study
- translucent
- letting light through, so you can partly see through it
- Southern Ocean
- the ocean that surrounds Antarctica
Discovery challenge
-
What does the colossal squid have on its arms?
What is special about the colossal squid's arms and tentacles?
Which character distinguishes the colossal squid's tentacle clubs?
- Feathers
- Hooks
- Shells
Show the answer
Hooks
It has hooks! Some of them can swivel.
Its arms have hooks and suckers, and its tentacle tips have two rows of swiveling hooks.
Two rows of swiveling hooks on the tentacle club; the arms bear hooks and suckers.
-
Where does the colossal squid live?
Which ocean is the colossal squid's home?
What is the core range of Mesonychoteuthis hamiltoni?
- A warm coral reef
- The cold sea around Antarctica
- A river
Show the answer
The cold sea around Antarctica
It lives in the icy sea near Antarctica.
The Southern Ocean around Antarctica.
Sub-Antarctic and Antarctic waters of the Southern Ocean, adults below about 1,000 meters.
-
What did scientists film for the first time in 2025?
What happened for the first time in 2025?
What was recorded in 2025 during the Ocean Census expedition?
- A colossal squid laying eggs
- A young colossal squid alive in the deep sea
- A colossal squid on a beach
Show the answer
A young colossal squid alive in the deep sea
A baby colossal squid swimming in the deep sea!
Scientists filmed a young colossal squid alive, 600 meters deep, with a robot camera.
The first confirmed in situ footage: a 30-centimeter translucent juvenile at 600 meters near the South Sandwich Islands.
-
Which big animal eats colossal squids?
Which animal is known to eat colossal squids?
Which evidence shows the colossal squid is important prey for sperm whales?
- Sperm whales
- Penguins
- Seals
Show the answer
Sperm whales
Sperm whales eat colossal squids.
Sperm whales; colossal squid beaks are often found in their stomachs.
Beaks are about 14 percent of those in Antarctic sperm whale stomachs, an estimated 77 percent of the squid biomass eaten.
Places where you might see it
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For parents & teachers
What children will learn
- Describe the colossal squid's hooks, beak, eyes and where it lives.
- Explain how scientists learn about an animal they rarely see, using specimens, beaks and video.
- Understand why measurements of dead specimens can be misleading.
- Compare the colossal squid with the giant squid.
Recommended ages: 3 to 17 · About 15 minutes
Talk about it
- Why might a squid that lives in deep, cold water be so hard to find?
- How can a beak found inside a whale tell scientists how big a squid was?
- Why do you think it took 100 years to film a colossal squid alive?
Try at home or in class
- Measure 2.5 meters on the floor and lie down next to it: that is the length of the colossal squid's body without its arms.
- Leave a slice of apple out for a day and measure it before and after to see how drying can make something shrink, like a preserved squid.
Key vocabulary: invertebrate, mantle, beak, specimen, translucent, Southern Ocean
Where these facts come from
- The IUCN Red List of Threatened Species , International Union for Conservation of Nature (IUCN terms of use (no redistribution of Red List data or range maps))
- GBIF Backbone Taxonomy and GBIF Occurrence Search , Global Biodiversity Information Facility (CC0 1.0 (backbone); occurrence counts are facts derived from records under CC0, CC BY and CC BY-NC)
- Mesonychoteuthis hamiltoni (Barratt & Allcock 2014) , IUCN Red List of Threatened Species
- Colossal squid at Te Papa , Museum of New Zealand Te Papa Tongarewa
- How big is the colossal squid on display? , Museum of New Zealand Te Papa Tongarewa
- Colossal squid Mesonychoteuthis hamiltoni , Museum of New Zealand Te Papa Tongarewa, Collections Online
- First footage of live juvenile colossal squid filmed on the Ocean Census expedition (2025) , Nekton / The Nippon Foundation-Nekton Ocean Census
- A unique advantage for giant eyes in giant squid (Nilsson et al. 2012, Current Biology 22: 683–688), abstract , PubMed, US National Library of Medicine
- Wikidata , Wikimedia Foundation (CC0 1.0)
- Wikimedia Commons , Wikimedia Foundation (Per file: Public domain, CC0, CC BY or CC BY-SA only (credited on each page))
Checked, not yet human-reviewed. Last updated October 27, 2026. Spotted a mistake? Tell us.