In the far south, where darkness and ice rule the sea, a sudden break in the frozen landscape has exposed a hidden frontier.
At the start of 2025, a massive iceberg calved from Antarctica, forcing a research vessel to alter course and revealing a pristine stretch of ocean that had never been seen by human eyes. That detour led to the first confirmed footage of an extraordinarily elusive glass squid, followed by the surprise sighting of a juvenile colossal squid weeks later.
A wandering iceberg opens a secret Antarctic seascape
The story begins with iceberg A-84, a vast slab of ice that detached from the Antarctic ice sheet in January 2025. Icebergs break away from the continent regularly, but their movement can radically reshape access to the seas below and around them.
This particular iceberg drifted into the planned path of the R/V Falkor, the research vessel operated by the US-based Schmidt Ocean Institute. The team had to redesign their route through the frigid waters of the Southern Ocean, a region already notorious for fierce storms and treacherous sea ice.
That change of plan led them to a patch of ocean that had been shielded for decades by thick sea ice. Once the ice moved off, light, currents and nutrients began to flow differently, revealing a freshly accessible ecosystem that had effectively been walled off from the surface.
The iceberg’s unexpected drift turned a logistical headache into a rare window on a deep, untouched Antarctic habitat.
First-ever video of an Antarctic glass squid
While surveying this newly accessible area in late January, scientists deployed a remotely operated vehicle (ROV) to depths nearing 700 metres. Cameras on the ROV captured what researchers later confirmed as the first visual record of Galiteuthis glacialis, an Antarctic “glass squid”.
The species was first described in 1906 from dead specimens recovered in nets. Since then, it had become a sort of ghost of the Southern Ocean: known from fragments and preserved bodies, never alive in its natural environment.
Glass squids are named for their almost see-through bodies. Their transparency helps them blend into the dim, blue-green light of the midwater zone, making them difficult for predators — and cameras — to detect.
Seeing Galiteuthis glacialis alive, hovering in the dark water column, turns a vague drawing from an old taxonomy book into a real, breathing creature.
➡️ The ingredient you need to add to your mop bucket for floors that stay clean longer
➡️ Mystery of the Virgin Mary’s bloody tears: DNA analyses reveal surprising conclusions
➡️ Lidl to launch Martin Lewis-approved gadget next week – just in time for winter
➡️ A study reveals that “fecal transplantation” could help fight diabetes and heart disease
➡️ Add salt to your washing-up liquid to fix your biggest kitchen problem
➡️ Feeling emotionally overloaded without clear cause is more common than you think, psychology says
➡️ “After 65, my sleep became lighter”: the phase of sleep that quietly disappears
Endemic to Antarctic waters, the squid observed by the R/V Falkor team appeared small and delicate, with long fins and a gelatinous mantle, drifting just above the deeper abyss. Researchers noted its careful, energy-efficient movements, consistent with life in a cold, nutrient-stretched environment.
Why no one had seen it alive before
There are several reasons this squid has remained unseen for more than a century:
- It lives far from coasts, in remote Antarctic waters rarely visited by ships.
- Its main depth range sits between surface and seabed, where standard trawls often miss animals.
- Its transparent body makes it hard to detect with traditional lights and cameras.
- Harsh Antarctic conditions limit the time and equipment scientists can use at sea.
Only recently have high-resolution cameras, low-light sensors and more agile ROVs made it realistic to film such animals in place rather than drag them up in nets.
A second surprise: a juvenile colossal squid on camera
The first squid sighting might have been enough to define the expedition. Yet on 9 March, the same team recorded something arguably even more striking: a juvenile colossal squid, another glassy-bodied animal, gliding through the dark.
Colossal squids (Mesonychoteuthis hamiltoni) are among the heaviest invertebrates known. They are deep-sea hunters with muscular bodies and arms lined with sharp hooks, adapted for ambushing prey in near-total darkness. Until now, most of what scientists knew about them came from damaged adults pulled up by fishing vessels, or from remains found in the stomachs of sperm whales.
The juvenile filmed by the expedition was far smaller than the legendary adults, yet clearly showed the species’ typical traits: large eyes, a bulky mantle relative to its length and hook-bearing tentacles.
Colossal squid can reach about 7 metres in length, while the Antarctic glass squid stays much smaller, even at maturity.
Seeing both species within weeks, on successive dives, stunned the team. As Schmidt Ocean Institute director Dr Jyotika Virmani noted, the twin sightings underline how little direct contact humans have had with the residents of the deep Southern Ocean.
Side-by-side: two rare squids from the Antarctic depths
| Feature | Antarctic glass squid (Galiteuthis glacialis) | Colossal squid (Mesonychoteuthis hamiltoni) |
|---|---|---|
| Typical adult size | Relatively small, modest mantle length | Up to ~7 metres total length |
| Body appearance | Highly transparent, delicate | More robust, semi-transparent in younger stages |
| Arms and tentacles | Slim arms, simple suckers | Powerful arms with sharp hooks used for gripping prey |
| Habitat | Midwater Antarctic zone, several hundred metres deep | Deep Antarctic waters, often at greater depths |
| Scientific status | Known since 1906, first live video in 2025 | Known from carcasses; juvenile filmed alive in 2025 |
What this reveals about Antarctic deep-sea life
The pair of sightings came during a wider Schmidt Ocean Institute mission focused on mapping deep habitats and cataloguing species around Antarctica. Alongside the two squids, the team logged other little-known organisms from the twilight zone and beyond, including bioluminescent jellyfish and strange crustaceans adapted to crushing pressure.
These findings hint at a rich food web sustained not by sunlight but by sinking organic material — dead plankton, faecal pellets and occasional larger carcasses that drift down from surface waters. Squids sit near the middle of this system, both hunting smaller animals and serving as prey for larger predators such as whales, seals and large fish.
For climate scientists, the region matters for another reason. As sea ice retreats and icebergs shift, the structure of Southern Ocean ecosystems may change. Species specialised for cold, dark, stable conditions could find their habitats altered on timescales they cannot easily match.
Why chance still shapes big scientific breakthroughs
The Antarctic squid story is a reminder that much of ocean science still hinges on serendipity. The team on the R/V Falkor did not set out expecting to photograph two rare squids in quick succession. They were pushed into that position by an iceberg, then ready with the right tools when the opportunities appeared.
In practical terms, this means research programmes that can adapt on the fly often generate the most surprising results. Ships with flexible schedules, modular instruments and real-time analysis on board can follow promising leads instead of sticking rigidly to a script.
Chance events at sea only become breakthroughs when crews have the freedom and tools to turn “that looks odd” into “we just documented a species for the first time”.
Key terms and what they actually mean
Several technical phrases appear around this story that are worth unpacking:
- Calving: The process where chunks of ice break off from the edge of a glacier or ice shelf to form icebergs.
- Endemic: A species found naturally in one geographic area and nowhere else on Earth.
- Midwater or mesopelagic zone: The ocean layer roughly 200–1000 metres down, where there is still some light but not enough for photosynthesis.
- Remotely operated vehicle (ROV): An uncrewed, tethered underwater robot controlled from a ship, carrying cameras and scientific sensors.
Understanding these terms helps frame why sightings of live deep-sea animals are so rare. Most live in places humans cannot safely visit without specialised machines, in darkness that needs sensitive equipment to penetrate.
What might come next in Antarctic deep-sea research
These squid encounters are likely to spur more Southern Ocean expeditions over the next decade. Future missions may combine ROVs with autonomous underwater vehicles that roam without tethers, increasing the area scientists can cover beneath shifting ice and around newly calved icebergs.
Researchers are also starting to use environmental DNA, or eDNA, sampling in these waters. By filtering seawater and analysing genetic traces left by organisms, teams can detect species that never pass in front of a camera. In an ecosystem where many animals remain unseen, this method could reveal patterns of presence and migration long before every creature is filmed.
For now, though, the sight of a fragile glass squid hanging motionless at 700 metres, and a young colossal squid bristling with hooks in the gloom, offers something rare: a direct glimpse of life in a part of the planet that still resists easy storytelling, even as the ice above begins to shift and crack.