First Photographs of a Live Giant Squid in the Wild, Ogasawara Islands, 2004

The kraken is one of the oldest monsters of the sea. Its real counterpart, the giant squid Architeuthis, had long been known only from carcasses. One count put it at more than 580 washed ashore since the 1500s. Another spoke of 250 dead or dying, none ever caught alive. No one had photographed a living one in the deep.

Tsunemi Kubodera, a zoologist at the National Science Museum in Tokyo, set out to change that. He arrived in the Ogasawara Islands in late 2002. There he worked with Kyoichi Mori, a Chichijima native and member of the Ogasawara Whale Watching Association who specialised in sperm whales. Sperm whales eat giant squid. They gather off Ogasawara to feed from September to December. Their dives pointed to the hunting grounds. 800 to 1,000 metres by day.

The team hung a long line beneath three large floats. At the end was a lead squid jig with a triple hook crown, baited with squid and a mesh bag of shrimp as an odour lure. Above it sat a camera housing lent by the National Institute of Polar Research. Below 200 metres it switched itself on and took one image every 30 seconds. Over three seasons they made 23 deployments.

30 September 2004. Open water off Chichijima. The seafloor lay about 1,200 metres below. The bait hung at 900 metres. At 09:15 the camera caught the strike. The squid came in horizontally. Its long tentacles wrapped in a ball around the bait. Then the club of one tentacle snagged on the jig.

For the first 20 minutes the squid disappeared from view, swimming actively away. For the next 80 it kept coming back to the line, spreading its arms widely or enveloping it. Then it hauled the entire camera system upward, from 900 metres to 600. Over the next three hours squid and rig slowly returned towards 1,000 metres. In the last hour the line was out of frame. The animal seemed to be swimming to break free.

Then, sudden slackness. Four hours and 13 minutes after the strike, the tentacle had broken.

The crew hauled up 5.5 metres of severed tentacle. It was still functioning. Its large suckers kept gripping the boat deck and any offered fingers. "It was quite an experience to feel the still-functioning tentacle on my hand," Kubodera said. "But the photos were even better." Its DNA matched known Architeuthis specimens from Japanese waters. The whole animal was estimated at greater than 8 m long.

The paper appeared in Proceedings of the Royal Society B in September 2005. The images went around the world. Steve O'Shea of Auckland University of Technology said: "Through sheer … determination the guy has gone on and done it." Randy Kochevar of the Monterey Bay Aquarium called it an "incredible accomplishment."

The pictures overturned an old idea of a sluggish squid trolling passively with its tentacles. "The long tentacles are clearly not weak fishing lines dangled below the body," the authors wrote. This was an active predator. Caveats remain. For most of the record the animal was hooked and struggling, and its length is an estimate. The full body was never recovered.

In 2006 the same team videotaped a live giant squid at the surface. In 2012 Kubodera, O'Shea and Edith Widder filmed one from a submersible off the Bonin Islands. The kraken had become an animal. Yet the paper's closing words still stand: "There is still much to learn about these spectacular animals."