Octopuses are damn strange creatures. Beautiful, but strange. Even by their freakish standards, this recently filmed behavior is particularly peculiar.
The video shows a wild octopus darting around a shallow-water reef in Australia, when it appears to approach the diver. The octopus then scoops up water and engorges itself, “ballooning” up and appearing considerably larger than it is.
Marine biologists are a little confused as to why the octopus is behaving like this. Could it be trying to intimidate the diver by looking like a tough guy? Or is it a hunting technique?
PT Hirschfield, the writer and diver who shot the amazing footage, explained in a blog post: “Whether it rushed towards me purely for having sensed some doomed crab’s movement near me which it then puffed itself up like a parachute to capture, or whether its attack posture was also intended to intimidate me remained a mystery.”
The intimidation theory is perhaps the most obvious of the options. Species across the animal kingdom are widely known to alter their appearance, often by making themselves appear larger to ward off any would-be predators. Such species include pufferfish, toads, frilled lizards, and even your cat as it arches its back when under threat.
On the other hand, Professor Kathleen Sullivan Sealey, an associate professor of biology at the University of Miami, told Live Science it's more likely that this octopus was actually hunting prey.
"It's shooting water out of its mantle,' said professor Sullivan Sealey. “It was using that water to chase little shrimp out from the rocks so that they would get caught in its legs and the webbing between its legs.”
Either way, this is some fascinating behavior and serves as a reminder not to get on the wrong side of this majestic animal.