Rare Squids Filmed Near Antarctic Iceberg A-84

Rerouted by a freshly calved mass of ice on Antarctica’s fringe, a US-led expedition captured footage of two exceptionally elusive deep-sea squids, uncovering an ecosystem concealed beneath ice for centuries.

A drifting iceberg reveals an unseen frontier

Early in 2025, a huge iceberg designated A-84 separated from the Antarctic ice sheet and began moving into the Southern Ocean. Although calving is a normal element of Antarctica’s natural cycle, these events can bring striking and unforeseen consequences for wildlife and nearby research ships.

In January, the US-based Schmidt Ocean Institute’s research vessel Falkor had to alter its route as A-84 travelled through the area. That diversion carried the crew above a section of seabed which, until very recently, had been buried beneath substantial ice.

The freshly uncovered site gave scientists an unusual opportunity to examine a cold, deep ecosystem shaped with minimal interference from conditions at the surface.

By shifting their route around iceberg A-84, researchers unintentionally sailed straight into one of the most surprising deep-sea encounters of the decade.

A glass squid observed alive in its Antarctic habitat

On a remotely operated vehicle (ROV) dive approaching 700 metres, the expedition obtained the first confirmed video of Galiteuthis glacialis, a glass squid species almost never witnessed in the wild.

The species was first formally described in 1906 using preserved specimens brought up in nets. It has remained largely unknown ever since, with no living specimen previously filmed in its natural Antarctic environment.

Why glass squids are so distinctive

Glass squids take their name from their almost transparent bodies. In the deep sea, this translucency provides camouflage, as a solid outline can reveal an animal to both predators and potential prey.

• The majority of their bodies is transparent, limiting shadows in low light.
• Their organs are compactly positioned to reduce visual contrast.
• Certain species contain light-producing organs that match faint ambient light.

Galiteuthis glacialis is believed to occur only in Antarctic waters, which makes it a Southern Ocean endemic. The ROV recording depicts a small, fragile squid suspended in frigid darkness, with its slender mantle and fins only faintly distinguishable from the surrounding water.

The confirmed sighting of Galiteuthis glacialis turns a century-old name on a specimen jar into a living, swimming animal at nearly 700 metres depth.

A juvenile colossal squid is filmed next

The discoveries extended beyond a single uncommon squid. On 9 March, a further Schmidt Ocean Institute expedition within the same research programme recorded what is thought to be a juvenile colossal squid, another member of a glassy deep-sea lineage.

The colossal squid, Mesonychoteuthis hamiltoni, has acquired an almost mythical reputation. Just a small number of adults have been retrieved, generally dead or dying after becoming caught in fishing equipment or being discovered in sperm whale stomachs.

A hunter equipped with hooks

Even in its juvenile stage, the colossal squid displays the characteristics that make the adults such imposing predators. As with many deep-sea squid species, it has sharp hooks on its arms and tentacles. Functioning much like grappling tools, they enable the squid to seize and retain prey struggling in the darkness.

According to the Schmidt Ocean Institute, the colossal squid can grow to around 7 metres long, making it one of Earth’s largest invertebrates. Galiteuthis glacialis, by comparison, is much smaller and more delicate in form, despite both species looking glassy and ghost-like in footage.

Two different rare squids, filmed on back-to-back expeditions, show just how little of the Southern Ocean’s deep life has actually been seen by human eyes.

Why Antarctic iceberg calving matters to ocean science

An iceberg calving does not simply redraw maps. It unveils fresh stretches of seafloor, alters currents and light conditions, and affects the circulation of nutrients through the water column. Together, these changes can temporarily influence the species that flourish locally.

For scientists, mobile ice represents both an opportunity and a danger. Vessels need to monitor iceberg movements closely to prevent collisions, but altered routes may also cross places that were formerly inaccessible or appeared unremarkable on maps.

The sightings of these two squid species near A-84 demonstrate clearly how moving Antarctic ice can change the direction of research and expose phenomena previously known only in theory or from preserved specimens.

What the sightings reveal about deep-sea life

The Southern Ocean ranks among the world’s least researched marine environments. Its isolated location, severe weather and dense ice cover make sustained observation particularly challenging. For many species listed by scientists, the name still relates to a preserved animal caught in a net rather than a living creature recorded in its habitat.

Observing Galiteuthis glacialis and a juvenile colossal squid alive offers fresh evidence about their movement, hunting and predator avoidance. Features including the position of their fins, the way they arrange their arms and their response to ROV lighting can all contribute to models of deep-sea behaviour.

The observations further emphasise the extent to which Antarctic deep-sea food webs depend on animals that seldom, if ever, come near the surface. Squids such as these may provide important prey for major predators, including sperm whales and deep-diving seals.

Key terms behind the headlines

What scientists mean by “glass squid”

“Glass squid” is a broad label for several related species in the family Cranchiidae. They have several characteristics in common:

• Most feature transparent skin and internal tissues.
• Many have large eyes adapted for very faint light.
• They commonly live at midwater depths of roughly 200 to 1000 metres.

Their transparency serves a practical purpose beyond being unusual. In the weak, filtered light at these depths, a clear body helps them avoid detection by predators above and prey below.

What 700 metres means in practice

At 700 metres, the water lies in the mesopelagic, or “twilight”, zone, as oceanographers describe it. Sunlight reaches this layer, but it is not strong enough to support photosynthesis.

Near Antarctica at this depth, temperatures are close to freezing and pressure is roughly 70 times greater than at the surface. Animals that inhabit it require specialised adaptations for a slow metabolism, efficient movement and survival under intense pressure.

Future missions and their potential discoveries

Over the coming years, the Schmidt Ocean Institute and other scientific teams intend to mount additional expeditions near recently calved Antarctic ice. Better satellite monitoring of icebergs allows researchers to schedule voyages close to areas newly released from ice cover.

Every mission brings hazards as well as potential rewards. Rapidly changing weather can leave ships with escape routes blocked by ice, while ROVs must contend with drifting fragments and variable currents. At the same time, these circumstances offer opportunities to document species never previously recorded on film.

For people following ocean and climate news, the sightings prompt further questions. If two rare squids can emerge on successive cruises, what other creatures inhabit Antarctica’s dim waters without video footage, a common name or more than a brief entry in scientific catalogues?

As ice keeps moving and long-range research vessels travel farther into these remote places, further hidden inhabitants may become visible, converting long-held assumptions about life in the Antarctic deep into direct evidence.