Octupuses Socially Interact More Than We Thought

Octupuses are capable of showing a stormy range of emotions by changing their eight-limbed bodies' colors, and they interact socially more of the time than researchers had previously thought, as a new study reports.

The work was reported in the journal Current Biology.

The team of scientists from Alaska Pacific University (APU) and the University of Sydney (USYD) watched 52 hours of videotaped octopus doings to learn about the creatures. A lot is going on down there, they concluded.

"We found that octopuses are using body patterns and postures to signal to each other during disputes," David Scheel of APU, said in a release. "The postures and patterns can be quite flashy, such as standing very tall, raising the body mantle high above the eyes, and turning very dark."

The octupuses in the study were Octupus tetricus -- also called Typical Sydney Octupus (don't you wish your city had one?) -- and lived in shallow water in Australia's Jervis Bay. A diver had let a cephalopod-follower online community know that he had noticed something interesting among the octupuses there. After that, the scientists saw 186 octupus interactions and in excess of 500 actions. That was a good deal of movement and social interplay for a creature generally regarded as solitary.

There were definite patterns. For instance, when a dark, looming octopus drew near to another octopus, the next step was likely grappling. Pale-colored octupuses in any exchange were usually in retreat. When a light octopus approached a darker one, the latter generally stood firm. "Dark color appears to be associated with aggression, while paler colors accompany retreat," Scheel said in the release.

There were other ways to intimidate. For example, some octopuses stood on high ground with their "web" spread and mantle raised. The idea seemed to be for the octupuses to appear big and conspicuous.

These types of interactions seem to occur among octupuses in areas where food is present in high quantities and it isn't easy to hide. The team plans to continue to learn more about how the creatures' social interactions might affect population size.

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https://www.npr.org/sections/thetwo-way/2016/01/28/464447457/shifting-colors-of-an-octopus-may-hint-at-a-rich-nasty-social-life