In the new Netflix documentary "Our Oceans," stunning footage captured a coconut octopus using its siphon to shoot stones at predatory fish while hiding inside a clamshell—a behavior never before documented. The coconut octopus (Amphioctopus marginatus), also known as the veined or reticulated octopus, was observed pelting encircling fish with stones, using its siphon as a defense tool.
Filmed in Southeast Asia at a depth of about nine meters, the events were part of the documentary that focuses on the impacts of plastic pollution on marine life. The filmmakers were initially studying the effect of plastic pollution on the ocean, focusing on a lone octopus living in a trash-filled seabed, when they stumbled upon this surprising defense strategy.
"We couldn't believe it. She was shooting fish, with stones, through her siphon! We were so surprised. Nobody had ever recorded veined octopuses using their siphons as weapons before," Katy Moorhead, assistant producer and field director for the series, stated, according to Live Science.
To determine if this use of the siphon as a weapon was an isolated incident or a common practice in this species, the team returned to observe the octopus for another three weeks. Roger Munns, the director of photography, spent 110 hours with the octopus over this period, capturing its behavior in detail. The detailed footage showed the octopus gathering rocks and debris, loading them into its siphon, and then shooting them as projectiles at fish, as if it were a gun.
The behavior was so quick that the filmmakers had to play back the footage in slow motion to capture the shots of the octopus firing projectiles. "Faced with a large fish who was giving away the location of her clam hideout, the octopus fired a stone out of its breathing siphon, and hit the fish square on the face," James Honeyborne, the executive producer, described to Live Science.
Narrated by former US President Barack Obama, the series highlights this remarkable discovery. "She turns her siphon into a gun," Obama said in the show. "Until now, we didn't know an octopus could arm itself like this. Genius," he added.
Scientists are currently investigating this newly recorded shooting behavior of the coconut octopus to better understand how and why it throws stones at threatening fish. Using its siphon—a tube normally used for swimming—to launch projectiles has never been documented before. The never-before-seen behavior was only discovered after the team reviewed the footage.
Coconut octopuses are known for building armor from clam and coconut shells, pulling the halves together to create shields, and they have been observed hiding in shells and using them as armor. When not in use, they carry these shells around with them, stacking them up, sitting inside the shells, then sticking their arms out to move along the seafloor.
They get their name from their habit of lodging themselves inside empty coconut husks. Coconut octopuses, also known as Amphioctopus marginatus, are typically found in sandy, muddy habitats in shallow waters of the tropical western Pacific Ocean. They are found throughout the Indian Ocean and emerge from their hiding places at dawn and dusk to forage.
Jonathan Smith, the series producer, concluded: "The fish were clearly startled and then swam away from the octopus, which suggests it's an effective deterrent," according to 20 Minutos.
Live Science, 20 Minutos, Marca, and The Sun were among the websites that reported on the out-of-the-ordinary footage.
This article was written in collaboration with generative AI company Alchemiq