Professor David Scheel of APU has recently been a part of a research team studying Octopus behavior. The team studied more than 20 hours of octopi footage. “I call it octopus TV,” laughs co-author David Scheel, a behavioral ecologist at Alaska Pacific University in Anchorage. While combing through the footage, one behavior stood out the most. Instances where the octopus would gather shells, silt, or algae with their arms before hurling it away, propelling them with just water jetted from their siphon. And although at times it seemed that they were throwing away debris or food leftovers, it did sometimes appear that they were throwing things at each other.
The team found clues that the octopus was deliberately targeting one another. Throws that made contact with another octopus were relatively strong and often occurred when the thrower displayed a uniform dark or medium body color. Another clue: sometimes, the octopus on the receiving end would duck. Throws that made contact were also more likely to be accomplished with a specific set of arms, and the projectile was more likely to be silt.
“We weren’t able to try and assess what the reasons might be,” Scheel cautions. But throwing, he says, “might help these animals deal with the fact that there are so many octopuses around.” In other words, it is probably social. Tamar Gutnick, an octopus neurobiologist at the University of Naples Federico II in Italy, says the work opens a new door for inquiries into the social lives of these famously clever animals. “The environment for these specific octopuses is such that they have this interaction between individuals,” she says. “It’s communication, in a way.”
Prof Peter Godfrey-Smith, first author of the research at the University of Sydney, said the behavior is surprising, “The throwing – or propelling, or projecting – of objects that have been gathered and held is rare in the animal kingdom. To propel an object, even for a short distance, underwater is especially unusual and also quite hard to do,” he said. But Godfrey-Smith suggested the strikes could have a purpose. “I think quite a lot of it is a bit like an assertion of ‘personal space,’” he said. “In quite a few cases, females have thrown material at male octopuses who have been attempting to mate with them … But in other cases, females throw and hit other females.”
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