for National Geographic News
Monster-size, deep-sea squid that use their glowing arms to blind and stun their prey have been filmed in the wild for the first time, scientists say.
The mysterious creatures were videotaped as they hunted deep in the North Pacific Ocean off southeastern Japan (map of Japan).
The footage shows the animals—Dana octopus squid, or Taningia danae—targeting prey with bright flashes of light emitted from their arms. (See a video of the squid attacking.)
The squid appear to use the tactic to illuminate and stun their victims, writes the team that made the discovery.
Other glowing signals seen from the bioluminescent species may represent a form of communication, possibly for attracting a mate, the researchers add. (See a video of the squid flashing in the darkness as it swims around dangling prey.)
The human-size squid were filmed at depths of 780 to 3,100 feet (240 to 940 meters) off the Ogasawara Islands during a scientific expedition led by Tsunemi Kubodera of the National Science Museum in Tokyo, Japan.
It was off these same islands in 2004 that Kubodera's team captured the first ever images of a live giant squid (Architeuthis) in the wild.
Results of the more recent squid hunt, which took place in 2005, are reported this week in the biology journal Proceedings of the Royal Society B.
T. danae lacks the two long feeding tentacles of most other big squid.
But the species has suckers with sharp claws and light-producing organs on the ends of two of its arms called photophores. The size of lemons, these photophores are the largest found in the animal kingdom.
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