'Octopus city' under the sea floor of Australia

The underwater city of Octlantis in Australian waters is where octopuses live, but researchers have yet to explain how it forms.

Scientists discovered a small octopus city called Octlantis in Jervis Bay in Australia's east coast, Science Alert on Sept. 19. This finding suggests that members of the gloomy octopus (Octopus tetricus) may not be isolated and alone as previously thought.

Biologists recorded the octopus city.(Video: YouTube).

Octlantis consists of many burrows built from sand dunes and shells, the home of 15 individuals, according to marine biologists. They spent 10 hours filming the octopus city at a depth of 10 - 15m under water and measuring 18 x 4 meters. Research results are published in the Journal of Behavior and Physiology of Marine Animals and Fresh Water.

The international team saw octopuses meet, live together, communicate with each other, chase some uninvited guests and even banish their kind from the cave. It seems that Octlantis is not an easy place to live.

"These behaviors are the product of natural selection , and are particularly similar to the complex social behavior of vertebrates. This indicates that when conditions are right, evolution can create Similar results in diverse biological organizations , " said David Scheel, head of research at Alaska Pacific University.

The new octopus city is located very close to another similar site discovered in 2009 named Octopolis . There, researchers found many pieces of predatory prey scattered around the city, even used to build cave walls.

Normally, octopuses only meet each other to mate, then split again.

Both locations help prove that the Octopus tetricus octopus does not live alone. However, researchers are not sure if small octopus cities are popular or how they form.

Octopolis seems to surround an unidentified artificial object about 30 centimeters long but there is no similar object in Octlantis. Researchers speculate at first that protruding slabs could attract octopus to the area. The two cities also have abundant food sources but also attract predators.

Normally, octopuses only meet each other to mate, then split again. But scientists need to do more research to understand why they decided to live together in cities like the Oclantis.