6 astounding behaviours of octopuses
By Jaymi Heimbuch,
Mother Nature Network, 13 April 2016.

Do you ever wonder if octopuses will one day take over as the planet's most intelligent species? (And let's get something out of the way: yes, octopuses is the correct plural.) No one could blame you if you believed in the eventual planetary take-over by these eight-armed wonders of the sea. They regularly show us just how clever, creative and downright amazing they are. They're weird, fascinating and for the most part, entirely unknown.

Do we underestimate them? Most definitely. And these six behaviours are reminders that we really shouldn't put anything past them.

1. They use coconuts as mobile hideouts

A species of octopus was dubbed the coconut octopus - and for good reason. Amphioctopus marginatus was discovered in 1964 and has a stand-out behaviour. It is known to collect coconut shells and use them as shelter. But not only do they collect them, they carry them around, holding them to their bodies while walking across the sea floor. It's one of only two species of octopus known to show bipedal locomotion. Check it out in the above video.

Julian Finn of the Museum Victoria in Australia says of witnessing the behaviour: “While I have observed and videoed octopuses hiding in shells many times, I never expected to find an octopus that stacks multiple coconut shells and jogs across the seafloor carrying them. I could tell that the octopus, busy manipulating coconut shells, was up to something, but I never expected it would pick up the stacked shells and run away. It was an extremely comical sight - I have never laughed so hard underwater.”

Not only can octopuses make their own tools, but they can figure out how to manipulate tools created by humans. Octopuses can successfully open jars to get food.

They can also open jars from the inside. (Leave it to an octopus to one-up humans on something like this.)

2. They have devious hunting strategies

Some species ambush their prey or stalk prey until they're close enough to pounce - or they simply chase their prey down. But these strategies require the predator going to the prey. The larger Pacific striped octopus takes a different approach: it pranks its prey, tricking the victim into running toward the predator.

Roy Caldwell, a professor of integrative biology at the University of California Berkeley, told Berkeley News, "I’ve never seen anything like it. Octopuses typically pounce on their prey or poke around in holes until they find something. When this octopus sees a shrimp at a distance, it compresses itself and creeps up, extends an arm up and over the shrimp, touches it on the far side and either catches it or scares it into its other arms." Sneaky devil.

While this is certainly a wily strategy, it isn't the only amazing hunting an octopus can do. Octopuses don't even have to stay in the water to catch their next meal. Check out when this octopus ambushes a crab above the water in a tidepool. Prey isn't safe above or below the water!

3. They shape-shift into toxic fish and sea snakes

If you can't hide under a rock somewhere, hide in plain sight. That seems to be the motto of mimic octopuses. There are at least 15 different species of mimic octopus, which have the ability to contort their eight-armed bodies into the shapes of other animals that predators typically want to avoid, such as poisonous flatfish, lionfish, jellyfish or even sea snakes.

According to Dive The World, "The fact that all of the species it imitates are venomous, adds to the likelihood that this is an evolved and deliberate strategy... Which variation is seen seems to vary depending upon the particularities of the predators in the area. Factors such as the proximity, appetite and environment present may all affect the choice that the mimic makes."

4. They have surprising social lives

Octopus mating. Photo: N (Offthebeatentrack)/Flickr, CC BY-NC-ND 2.0.

Octopuses are usually solitary creatures. In fact, their loner ways are so well known that when Panamanian biologist Aradio Rodaniche documented the Pacific striped octopus living in groups of up to 40 individuals in 1991, not just tolerating each other but mating sucker-to-sucker and laying multiple clutches of eggs, his account was written off as ridiculous. It wasn't until 20 years later when biologist Richard Ross of the California Academy of Sciences came across a group and began to study them that the truth of their unusual social behaviour was acknowledged.

It isn't just that they can live together in close proximity much more tolerantly than other known octopus species. It's also their mating practices that are a surprise. Most other octopus species mate from a distance with a "special" long arm because females will often kill and consume the male after mating.

But the Pacific striped octopus mates beak-to-beak, almost like they're kissing:

So much more is left to learn about this unusual species. “Only by observing the context in which these behaviours occur in the wild can we begin to piece together how this octopus has evolved behaviours so radically different from what occurs in most other species of octopus,” says Ross.

5. They brood eggs for years

Most of the time, female octopuses brood their eggs for a short time and then die. The brooding might last for a few weeks for a few months. But one female octopus set a new record at four and a half years. The deep sea octopus of the species Graneledone boreopacifica was spotted by researcher Bruce Robison and his team. They went back to the same spot over and over again for years, recognizing the same female by her distinctive scars.

As the years went by, her condition deteriorated. When the team first saw her, her skin was textured and purple, but it soon turned pale, ghostly, and slack. Her eyes became cloudy. She shrank. And all the while, her eggs grew bigger, suggesting that they were indeed the same clutch.
The team last saw her in September 2011. When they returned in October, she was gone. Her eggs had hatched and the babies within had swum off to parts unknown, leaving nothing but tattered and empty capsules still attached to the rock. Her body was nowhere to be seen.
This is the longest brooding time recorded not only among octopuses but among any animal on Earth.

6. Unbelievable contortionists

Octopuses love to snuggle up in a tight space for protection. Spots that would make us feel completely claustrophobic are exactly the kind of space that these squishy invertebrates love. And since there are no bones to worry about, the range of places through which an octopus can squeeze is limited by the only rigid thing in its body: the beak. If the beak fits through, the rest of the octopus will, too.

Squeezing under rocks or into crevices is an octopus' natural escape mechanism, but sometimes their contortionist abilities are mind-boggling [see above video for example].

Octopuses are famous for being able to squeeze themselves into beer bottles, or escaping through openings a tiny fraction of their size. If you're trying to care for an octopus, it's wise to remember these escape-artist abilities. In fact, the New York Times recently reported on an octopus named Inky that escaped from a New Zealand aquarium. Inky was about the size of a soccer ball, and this wily creature reportedly slipped through a small gap at the top of his tank, slithered across a floor, and slid down a drainpipe, which dropped him into a bay.

“There are a lot of species of octopus, and most have never even been seen alive in the wild and certainly haven’t been studied,” Caldwell says. So if what we know about them so far is this spectacular, imagine what they're out there doing right now that we have yet to witness!

Top image: Coconut octopus (Octopus marginatus/Amphioctopus marginatus). Credit: Nick Hobgood/Wikimedia Commons.

[Source: Mother Nature Network. Edited. Some images added]

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