A few years ago, divers on Australia’s east coast discovered dozens of octopuses living together and getting along – more or less. The finding, named Octopolis, came as a huge surprise, because these are notoriously anti-social creatures that usually live alone.
Hours of diving and footage from cameras rigged around Octopolis are revealing complex behaviour: residents tussle and fight (but don’t kill each other), and communicate via colours flickering across their skins.
It’s thought that Octopolis was founded when a 30cm object – possibly made of metal – landed on a scallop bed. A few pioneers moved into this impromptu shelter, feeding on the surrounding shellfish.
The discarded shells then provided ideal material for fellow settlers to create dens, allowing the ‘city’ to expand. Octopolis is unusual, but not unique.
A second site nearby, known as Octlantis, is home to a similar throng, showing that these molluscs are not as unneighbourly as we previously thought.
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Main image: Common Sydney octopus showing a tentacle and suckers. © cbimages/Alamy