The Algae Octopus travels, mate and eats by day. In order to hide in broad daylight, it imitates algae. | National Geographic Animals

In a fascinating glimpse into octopus behavior, researchers have documented female gloomy octopuses (Octopus tetricus) engaging in what appears to be deliberate projectile throwing — targeting other octopuses with shells, silt, and algae propelled by jets of water from their siphons. A peer-reviewed 2022 study in PLOS ONE analyzed around 21 hours of underwater footage from Jervis Bay, Australia (2015–2016), revealing dozens of these “throws,” especially during social encounters such as fights, a