Deep-Sea Squid Blind Their Victims

Feb. 14, 2007 —Huge deep-sea squid use blinding flashes of light from their armtips to disorient their prey before attacking at speed, Japanese researchers have reported.

Using a newly developed, underwater video camera, a team led by Tsunemi Kubodera of the National Science Museum in Tokyo recorded the first live images of the mesopelagic large squid, Taningia danae.

These eight-armed creatures inhabit the ocean to depths of 3,250 feet and can grow more than 7.5 feet and weigh 132 pounds or more.

Far from being sluggish and neutrally buoyant, T. danae can swim nimbly backwards and forwards by flapping its large muscular triangular fins, and can turn in a jiffy thanks to its flexible body, Kubodera's team found.

But the research team's biggest surprise was to discover that the squid can make bright light flashes, lasting about one and a half seconds, from large photophores — clusters of light-emitting cells — before making an assault.

The light "might act as a blinding flash for prey as well as a means of measuring target distance in a dark, deep-sea environment," the scientists reported Wednesday in Proceedings of the Royal Society B, a journal of Britain's de-facto academy of sciences, the Royal Society.

The squid were filmed around bait rigs lowered to depths of between 780 and 3,055 feet off the Ogasawara Islands in the northwestern Pacific.

After the flash, the squid then attacked, attaining speeds of up to 5.5 mph, which is extraordinarily fast given the pressure of water at that depth.

From time to time, the squid emitted long and short glows "suggestive of potential courtship behaviours during mating," added Kubodera.

In September 2005, Kubodera and a colleague, Kyoichi Mori of the Ogasawara Whale Watching Association, reported on the first recording of a live giant squid, one of the strangest and most elusive creatures in the world.

The giant squid, Architeuthis, is a legend among mariners, the source of tales of tentacled monsters able to grab a ship and pull it down to its doom.

It memorably featured in Jules Vernes' "20,000 Leagues Under the Sea," trying to engulf the submarine Nautilus.