The squid drifted into the lights of the lander Nautilus-R at 03:42 ship-time on April 11, at a depth of 6,212 meters in the Kermadec Trench, roughly 1,100 kilometers northeast of Auckland.

Its body was perhaps 30 centimeters long. Its arms, held in the strange elbowed posture characteristic of the genus Magnapinna, trailed for nearly seven meters behind it.

For 47 minutes, the animal hung in the beam, occasionally rotating, occasionally extending and retracting its filament-thin arms in slow, deliberate sweeps of the water column.

It was the first sustained footage of a bigfin squid ever recorded. Previous sightings, of which there are perhaps two dozen worldwide since 1988, lasted seconds.

The expedition was a joint operation between the Japan Agency for Marine-Earth Science and Technology and the National Institute of Water and Atmospheric Research in Wellington, aboard the research vessel Kaikoura.

But Tane is cautious. "We have 47 minutes of one individual," she said at a press briefing in Wellington. "That is not biology yet. That is a glimpse."

Chief scientist Aroha Tane had spent six years pursuing the genus, deploying baited landers in the Tonga, Kermadec, and Mariana trenches with what she called "a budget made of patience and other people's leftover ship time."

The footage shows the squid responding to the lander's lights by slowly extending its arms outward, then folding them again into the characteristic right-angle posture that gives the family its informal name, the "long-arm" squid.

Marine biologist Henk de Vries of Leiden University, who reviewed the footage at Tane's request, called the behavior "unmistakably investigative," noting that the animal made three separate passes of the lander before drifting out of frame.

What the arms are for remains uncertain. The leading hypothesis, that they function as passive snares for marine snow and small crustaceans, gains some support from the footage, which shows the filament tips making contact with the seafloor and then retracting.

But Tane is cautious. "We have 47 minutes of one individual," she said at a press briefing in Wellington. "That is not biology yet. That is a glimpse."

The Kermadec Trench is the fifth-deepest in the world, reaching 10,047 meters at its lowest point. The bigfin squid was filmed at roughly 60 percent of that depth, in water just above 1.6 degrees Celsius.

The lander carried no thrusters. It had simply fallen, baited with a small canister of mackerel oil, and waited. The squid arrived alone, took its time, and left.

Tane intends to return to the same coordinates in November with a tethered ROV capable of close-approach imaging and, if possible, a sample.

She is also working with a colleague at the University of Auckland to model the hydrodynamics of those impossibly long arms in trench-bottom currents.

The footage has been deposited with the Auckland War Memorial Museum's natural sciences archive, and a 90-second public excerpt has been released through NIWA's open data portal.

It is easy, watching it, to forget that the animal is real and not animated. It moves with the patience of something that has nowhere it needs to be.