Watch Out Humans, Octopus Are Building Cities!

Octopus tetricus image: Creative Commons John Turnbull Flickr.

Octopus Cities

Scientists have discovered an octopus city, and they’re calling it Octlantis! The cephalopod city is located in Jervis Bay off the coast of eastern Australia and suggests the gloomy octopus species (Octopus tetricus) are not the loners we thought they were.
Octopus are usually solitary creatures only getting together to mate before going their separate ways. But in Octlantis 10 to 15 of the gloomy octopus live in the city at once. Researchers even saw the gloomy octopuses communicating with each other, chasing unwelcome octopuses away, and even evicting each other from dens.

One octopus evicted another from its den (frames captured from video).

Maps of Octlantis a new octopus city in Jervis Bay Australia

The octopus metropolis is 18 meters (59 feet) long and between 10 to 15 (33 to 49 feet) under the water. The octopus makes their dens from discarded mollusk shells of eaten prey, adding to a sense of lawlessness within the city.
Octlantis is close to another similar site discovered in 2009 called Octopolis. And the second site is (Octlantis) is located just a few hundred meters away from the first site.

Rocks And Food

Both octopus cities are built around rocky outcroppings in the otherwise flat and featureless area, said Stephanie Chancellor, a Ph.D. student in biological sciences at the University of Illinois at Chicago and an author on the paper.
These underwater landscapes also attract an abundance of food, which means they are also attractive to predators, and from what the researchers have observed that octopus cities seem like a rather violent and aggressive place to live.

Octopus interactions. A second site occupied by *Octopus tetricus*.

“In addition to the rock outcroppings, octopuses who had been inhabiting the area had built up piles of shells left over from creatures they ate, most notably clams and scallops. These shell piles, or middens, were further sculpted to create dens, making these octopuses true environmental engineers.”
“These behaviours are the product of natural selection, and may be remarkably similar to vertebrate complex social behaviour,” lead researcher David Scheel, from Alaska Pacific University, told Ephrat Livni at Quartz.
“This suggests that when the right conditions occur, evolution may produce very similar outcomes in diverse groups of organisms.” [Science Alert]