July 15, 2015
Gloomy octopus trash talks opponents before fight
Octopuses have been thought of primarily as solitary animals that don’t really talk to each other. However, a newly released video has shown octopuses communicating with each other prior to and during confrontations.
According to the Australian researchers who captured the video, common Sydney octopuses spread their arms wide, stand tall – and even change both the color and texture of their skin to convey either aggression or submission.The researchers, who presented their findings at the recent Animal Behavior Society meeting in Anchorage, Alaska, said their observations paint the common Sydney octopus – also known as the gloomy octopus – as a more socially complex creature than previously believed.
"The expectation has been that if two octopuses meet, the big one eats the smaller one," David Scheel, a marine biologist at Alaska Pacific University, told National Geographic. "But if octopuses encounter each other routinely, they can't cannibalize each other all the time."
Fight or flight
Rather, octopuses communicate to either escalate or stay away from a conflict.
The team was able to record a range of interactions among the octopuses they observed — from reaching toward each other to grappling. Just a fraction of theses interactions escalated to full-blown fights.
In addition to the physical posturing between potential combatants seen in humans and other species, the gloomy octopuses also used their color and skin-changing abilities to send out messages. In particular, research team found the octopuses conveyed aggression with darker colors, while submission was denoted by lighter colors.
"If one octopus signals that he's coming over and not going to back down, and the other signals he is going to run away, that can end the interaction," Scheel said. "Whereas if they both signal that they're not going to back down, those are the (incidents) that tend to escalate."
Christine Huffard, a researcher at the Monterey Bay Aquarium Research Institute told National Geographic that these types of displays are seen in numerous other species.
“It's hard to know whether it's an intentional versus a physiological response,” Huffard noted. “For instance, we blush. We don't say, 'Hey, body, tell this person I'm embarrassed.' It's just something that happens."
Huffard agrees with the research team’s conclusion that the octopus signals serve as self-preservation.
"If you know from the beginning that you're probably going to lose or you're not really willing to give up an arm, you might as well tell your opponent that you don't want a fight,” she said.
(Image credit: Klaus Stiefel/Flickr)