A group of research biologists have just discovered an entire underwater city of octopuses. Of course, they are calling this community “Octlantis”.
According to the biologists, this “city” is comprised of “dens made out of piles of sand and shells, and is home to 15 of the cephalopds.” These are common Sydney octopuses congregating and socializing—even fighting—at this meeting spot.
Stephanie Chancellor, of the University of Illinois, at Chicago, notes, “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.”
The study author goes on to say, “These shell piles, or middens, were further sculpted to create dens, making these octopuses true environmental engineers.”
Apparently this “city” rests in only about 15 meters below the surface and is also only about 18 meters long and 4 meters wide. Within this outcropping they say they have found 23 octopus dens with 13 occupied and 10 vacant.
Using GoPro cameras, the research team was able to film just how the cephalopds interact within their underwater city. The cameras helped them get intimate coverage of mating, aggression, and even how some octopuses would evict others from some of the dens.
Chancellor goes on to say, “There were some apparent threat displays where an animal would stretch itself out lengthwise in an ‘upright’ posture and its mantle would darken. Often another animal observing this behavior would quickly swim away.”
In addition, David Scheel of Alaska Pacific University said he was surprised by the way octopuses seem to embrace social norms. He comments, “These behaviors are the product of natural selection, and may be remarkably similar to conditions occur, evolution may produce very similar outcomes in diverse groups of organisms.”
Finally, Scheel concludes, “Most commonly, the gloomy octopus seems to den by itself. For these complex behaviors to occur, I think they must encounter one another and interact regularly over generations, even if at any time there are more octopuses living a solitary life than interacting consistently throughout every day.”