sciencebriefs
13:00in productionCh. 1 · A creature known only from carcasses/ 13:00 · ceiling 15 min
Ecology · Life sciences

Giant squid

It took following sperm whales to a spot 970 kilometres south of Tokyo and a four-hour struggle on a baited line before anyone photographed a living giant squid, and it showed an aggressive hunter, not a passive drifter.

Giant squid, whose bodies reach roughly 5 metres with feeding tentacles extending to about 10 metres and eyes up to 27 centimetres across, the largest of any living animal apart from possibly the colossal squid, had never been photographed alive in the wild before 30 September 2004, when zoologist Tsunemi Kubodera and colleague Kyoichi Mori achieved it off Japan's Bonin Islands. Working from clues in sperm whale behaviour, since sperm whales are known predators of giant squid, they located a specimen roughly 970 kilometres south of Tokyo and set a baited line at 900 metres depth; an eight-metre squid attacked the lure and struggled against it for more than four hours, captured in over 500 images, before escaping and leaving a 5.5-metre tentacle behind. Kubodera went on to film a live adult giant squid on camera for the first time in December 2006, and in July 2012, working with Edith Widder and Steve O'Shea and using a bioluminescent lure designed to mimic a panicked jellyfish, captured the first video of a giant squid behaving naturally in its own deep-sea habitat from a submersible, footage that showed the animal actively hunting rather than the passive, drifting behaviour scientists had previously assumed.

Chapters & takeaways6
  1. 0:08
    A creature known only from carcasses

    Before 2004, everything known about giant squid behaviour came from dead or dying specimens, never a living animal observed in its own habitat.

  2. 2:10
    Following the whales to find the squid

    Kubodera's team used sperm whale behaviour as a guide to locate a likely giant squid location roughly 970 kilometres south of Tokyo.

  3. 4:20
    A four-hour struggle on a baited line

    The first photographed giant squid attacked a baited line at 900 metres depth and fought it for over four hours before escaping.

  4. 6:30
    Video of an adult, then video in its own world

    Kubodera filmed a live adult giant squid in 2006, then captured it behaving naturally from a submersible in 2012.

  5. 8:40
    A lure built to mimic panic

    The 2012 footage used a bioluminescent lure designed to imitate a distressed jellyfish, a signal known to attract predators in the deep sea.

  6. 10:50
    An active hunter, not a passive drifter

    The resulting footage overturned the prior assumption that giant squid were largely inactive, showing genuinely aggressive hunting behaviour instead.

Worth your time?

Yes. Study the whole thing.

4.5/ 5
What works
  • the specific numbers, the 970 kilometre search distance, the four-hour struggle, the 5.5-metre severed tentacle, ground an easily sensationalised story in checkable detail
  • distinguishing the 2004 photographs, the 2006 video of an adult, and the 2012 natural-habitat footage keeps three genuinely different achievements from blurring together
  • the shift from assumed passive drifter to observed active hunter is presented as a real behavioural finding rather than a vague update
What does not
  • it does not explain in detail why sperm whale behaviour specifically indicated the likely presence of giant squid at that location
  • the biology behind why a lure mimicking jellyfish distress attracts giant squid specifically is asserted rather than explained
Study it if
  • anyone who assumed giant squid had already been well studied alive, when in fact they had not until 2004
  • readers who enjoy a research story built on indirect clues, like following whale behaviour to find prey
  • people interested in how a lure designed around another species' distress signal became the key to filming a giant squid naturally
Skip it if
  • readers wanting a comprehensive natural history of giant squid biology and reproduction
  • anyone looking for dramatic narrative embellishment beyond the documented sequence of expeditions
The written brief4 min read

A creature known only from carcasses

For most of scientific history, everything known about giant squid came from specimens that were already dead or dying, carcasses washed ashore, remains found in sperm whale stomachs, or animals caught accidentally and hauled to the surface, none of which could reveal how the animal actually behaved in its own environment. Giant squid themselves are substantial creatures, with bodies reaching roughly 5 metres in length and feeding tentacles extending to about 10 metres, and they possess the largest eyes of any living animal apart from possibly the colossal squid, up to 27 centimetres across, an adaptation suited to detecting the scarce available light at the depths between 300 and 1,000 metres where they typically live. Despite this size and their wide distribution near continental slopes worldwide, no one had ever photographed one alive in its natural habitat before 2004.

Following the whales to find the squid

The breakthrough came from Tsunemi Kubodera, a zoologist at Japan’s National Museum of Nature and Science, working with Kyoichi Mori. Rather than searching randomly across the vast area giant squid might inhabit, the team used the behaviour of sperm whales, known predators of giant squid, as an indirect guide to a promising search location, ultimately positioning themselves roughly 970 kilometres south of Tokyo, off Japan’s Bonin Islands. On 30 September 2004, they deployed a baited line at a depth of 900 metres, and an eight-metre giant squid attacked it, remaining hooked and struggling against the line for more than four hours, during which time the camera captured over 500 images, the first photographs ever taken of a living giant squid in the wild, before the animal eventually escaped, leaving a severed 5.5-metre tentacle still attached to the line.

A four-hour struggle on a baited line

Kubodera continued pursuing further documentation in the years that followed, and on 4 December 2006 he achieved the first video footage of a live adult giant squid, extending the 2004 photographic breakthrough into moving images for the first time. That achievement held up as a genuine advance in its own right, since capturing motion revealed information about the animal’s movement and physical behaviour that still photographs alone could not, even though the 2006 footage still involved an animal that had been drawn toward the surface by researchers’ equipment rather than one observed entirely undisturbed in its natural deep-sea setting.

Video of an adult, then video in its own world

The most significant remaining gap, footage of a giant squid behaving naturally, unprovoked and undisturbed, in its own deep-sea habitat, was closed in July 2012, when Kubodera worked with Edith Widder and Steve O’Shea to capture the first such video from a submersible. Their approach relied on a bioluminescent lure engineered by Widder to mimic the light pattern of a distressed jellyfish, a signal known to attract predators looking for an easy meal in the deep sea, rather than any conventional bait. The resulting footage showed the giant squid actively hunting, a genuinely aggressive predator rather than the largely passive, drifting animal that prior indirect evidence and assumptions about its low metabolic needs had led many researchers to expect.

A lure built to mimic panic

The behavioural finding mattered beyond simply confirming that giant squid could be filmed at all. Prior assumptions about giant squid as slow, low-energy drifters had been based almost entirely on indirect evidence, stomach contents of predators, the condition of recovered carcasses, and general theoretical expectations about the energy costs of life at depth, none of which could actually settle how the animal hunted or moved when undisturbed. Direct observation of active, aggressive hunting behaviour overturned that picture with a specificity indirect evidence never could have provided, illustrating how much basic natural history about even large, striking animals can remain genuinely unknown simply because no one had yet managed to observe the creature alive in its own setting.

An active hunter, not a passive drifter

This is a satisfying and worthwhile story precisely because it shows how much patient, indirect reasoning, following whale behaviour to find a likely search area, engineering a lure around another species’ distress signal, went into achieving something as seemingly simple as photographing a large animal. Each of the three milestones, the 2004 photographs, the 2006 video, and the 2012 natural-habitat footage from a submersible, represents a distinct and separately hard-won achievement rather than one continuous discovery, and together they replaced decades of inference about giant squid behaviour with direct observation. Anyone curious how much of even prominent, well-known animal behaviour remains genuinely unobserved until someone works out how to actually look will find this well worth the time.

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