RENEE MONTAGNE, HOST:
Let's go to the sea now, into the secret life of the octopus. These creatures are famous for many things - their eight tentacles, their complex brains, the way they can change color and disappear in a cloud of ink. Plus, they have a reputation for being loners. NPR's Nell Greenfieldboyce has this report on a new study that shows just how wrong that is.
NELL GREENFIELDBOYCE, BYLINE: Off the southeast coast of Australia, there's a shallow spot with a lot of tasty scallops. It's a place where a species known as the gloomy octopus likes to hang out.
DAVID SCHEEL: There can be over a dozen octopuses or more at this site. Generally, during the Australian summer there's more.
GREENFIELDBOYCE: David Scheel is a marine biologist at Alaska Pacific University. He and two colleagues wanted to understand how these octopuses interact, so they've taken around 52 hours of underwater video. And right from the start, what they saw was dramatic.
SCHEEL: I took a look fairly early on at one sequence in which one octopus approaches another in a fairly menacing way. And he gets all dark, stands up very tall, and the other octopus crouches down and turns very pale.
GREENFIELDBOYCE: The pale one flees.
SCHEEL: And this is immediately followed by the first octopus approaching a third octopus that's nearby. And the third octopus turns dark and doesn't crouch down. He just stays where he is - holds his ground.
GREENFIELDBOYCE: As Scheel watched more video, he became convinced that octopuses use their bodies' color and posture to talk to each other. An aggressive octopus will turn black and try to look as big as possible, spreading out its tentacles. To him, it looks like an eight-armed Dracula looming over its prey.
SCHEEL: In my early notes, I was calling this the Nosferatu display.
GREENFIELDBOYCE: The researchers describe all of this in the journal Current Biology, and Crissy Huffard thinks it's pretty cool. She's at the Monterey Bay Aquarium Research Institute in California. And she says until fairly recently, scientists believed that octopuses were almost completely solitary, with pathetic social skills.
CHRISTINE HUFFARD: When they interacted, they either mated or ate each other. That was the overriding idea.
GREENFIELDBOYCE: But Huffard has done research on another octopus species showing that males take on a striped body pattern when they see another octopus. She thinks there's a whole lot left to learn about what happens when octopuses get together. Nell Greenfieldboyce, NPR News.
(SOUNDBITE OF SONG, "OCTOPUS'S GARDEN")
THE BEATLES: (Singing) I'd like to be under the sea in an octopus's garden in the shade. He'd let us in, knows where we've been, in his octopus's garden in the shade. I'd ask my friends to come and see.