Octopuses become darker to show aggression

(Mirror Daily, United States) – It’s not just in response to predators or for hiding, but octopuses change color to signal social intent among themselves as well. While they were normally known as solitary creatures, it seems that octopuses actually have several interactions and ways to display their intentions among each other.

A team of researchers from Sidney, New York, and Alaska conducted a tiring observational study on numerous octopuses interacting. They watched 52 hours worth of recordings made on a GoPro camera to examine the complex social signaling between the marine creatures. The study was prompted by the study’s co-author, Matthew Lawrence, observation of the behavior while diving in Jervis Bay, Australia.

It seemed that the behavior among octopuses was not truly detailed in the past, since they’re mostly found separated from one another. This made their social skills wildly unknown to us until now. However, they proceeded to watch around 50 octopuses and observe over 180 different interactions among them. Through the underwater footage, they were able to make some new discoveries about their behavioral patterns.

For example, an octopus’ ability to change color was commonly thought to be a tactic to hide from predators or simply show its state of distress. However, it’s also a signal.

Researchers found that octopuses change colors to display aggressive intent, such as when they are about to attack another of their kind. They strike a pose that maximizes their size, putting on a full display of their darkened mantle and tentacles. When they fight, called grappling, they attempt to make themselves look bigger and gain a darker tint.

If two of them display the same signs and are in proximity to each other, they will very likely fight.

On the other hand, when octopuses display a paler color, that means that they are signaling a more peaceful intent. They are either retreating from a fight or simply swimming around with no intention of starting a conflict. In fact, it was noted that octopuses who had changed their color to something pale were likely to run away from those who had darkened their mantle. It’s a clear sign that they’re not willing to fight.

The pale represents a non-confrontational behavior, according to co-author of the study, professor Peter Godfrey-Smith, from the City University of New York.

While it was known of their habit of changing color to denote how threatened or relaxed they are, it’s new to know that they actually make themselves look bigger and darker to show signs of aggression toward one another. That was the study’s purpose, and, as Godfrey-Smith stated, it was a lot harder than it looked.

Keeping track of dozens of octopuses swimming around is no easy task when they’re constantly changing shape and color.

Image source: vanaqua.org