“They’re basically hugging the [cage] and exposing parts of their body that they don’t normally expose to another octopus,”
“Some were being very playful, doing water acrobatics or spent time fondling the airstone [aquarium bubbler],” said Dölen.
Others stretched out all eight arms and just floated around, doing what the researchers described as “water ballet”.
https://www.theguardian.com/science/201