Meet Amphioctopus marginatus, the coconut octopus—a clever cephalopod that treats coconut shells like portable studio apartments. Found in tropical waters from Indonesia to Australia, this small, walnut-sized octopus doesn’t just find shelter; it lugs its home around like a determined underwater snail. Using its arms, it tucks discarded coconut shells (or clamshells) under its body, scuttling across the seafloor to avoid predators. If real estate is “location, location, location,” this octopus is the ultimate mobile homeowner.
Scientists first documented this behavior in 2009, confirming it as one of the few examples of tool use in invertebrates. The octopus doesn’t just hide in shells—it actively collects and transports them. If a shell is too heavy, the octopus flips it over, climbs inside, and “parachutes” down while clutching it, looking like a marine version of Mary Poppins. When threatened, it snaps the shell shut, creating an instant bunker. No shell? No problem. Some improvise with beer bottles or plastic cups, proving trash can be treasure in a pinch.
The coconut hustle isn’t just about safety. These octopuses “remodel” their shells, stacking two halves to create a spherical hideout. They’ve even been observed hoarding spare shells for future use—a behavior scientists call “resource accumulation.” Imagine packing a suitcase for a trip you might take someday, but with more tentacles.
Why coconuts? Likely because they’re abundant in coastal regions where these octopuses hunt for shrimp and crabs. The shells also provide better camouflage than sandy seafloor, blending with debris. And while hermit crabs famously borrow shells, coconut octopuses are pickier. They’ll test multiple shells for fit, rejecting ones that are cracked or too snug. Call it the cephalopod version of house hunting.
This behavior isn’t innate; juveniles learn it by watching adults. It’s a rare glimpse of cultural transmission in invertebrates, suggesting octopuses are smarter than we thought. Or, as one marine biologist joked, “They’ve mastered the art of moving day—they just don’t complain about sore arms afterward.”
So, next time you struggle with a heavy grocery bag, remember the coconut octopus. It’s out there, hauling its home across the ocean floor, one shell at a time. And if you spot one on a dive, don’t offer it a hand. It’s got eight.
