Octopuses are really good at blending in. They match their skin color and texture to whatever’s around them until it looks as if they’ve disappeared.
But no matter how hard they try, there are other reasons octopuses still stand out — at least to those of us who live above the water line. Here are a few ways octopuses set themselves apart:
1. They see with their skin.
No, they don’t have a million eyeballs. But scientists at the University of California in Santa Barbara discovered that octopus skin contains the same proteins that are found in eyes.
Just like the pupils of your eyes expand and contract with light, so do the muscles around an octopus’s chromatophores, which are the cells that allow it to change color. They probably don't pick up detail very well through their skin, but they definitely see the light!
2. They shape-shift.
Some octopuses are masters of the fake-out. The appropriately named mimic octopus would totally win Halloween with its ability to make itself look like something it’s not.
It might flutter along the bottom as a flounder ...
... get aggressive while taking on the persona of a venomous lionfish ...
... bluff near-certain death as a sea snake ...
... or just chill out while hiding as a piece of coral.
Of course, sometimes they give up on the whole disguise thing. Because it’s nice to just be yourself once in a while.
3. They have three hearts and nine brains.
Two of the hearts pump blood to the gills, and the third pumps blood to the organs in the rest of the octopus. According to Smithsonian, the third heart stops beating while the octopus is swimming.
4. They’re cannibals.
At least the giant Pacific octopus is. Found in the northern Pacific Ocean, adults often weigh more than 50 pounds. They prefer to live alone until it’s time to mate, which is probably for the best, since they eat almost anything they can get their eight arms on — from small sharks to each other.
5. They manipulate their own RNA.
Scientists may have just discovered how an invertebrate got so smart. It turns out that octopuses can edit their own RNA.
Think about it like this: If you’re building a house, you’re going to get an architect to draw up a blueprint. That blueprint is your DNA. To build the house, you’re going to have to hire a general contractor to execute what’s on the blueprints.
In humans, the general contractor mostly does what the blueprint says. He knows that putting in a deck when you wanted a pool could end up costing him a lot.
But for some reason, the octopus’s general contractor changes the plan in the heat of the moment. Literally. Scientists have known for a while that octopuses use RNA editing to function in the cold. But with new information on the extent to which they pull this off, researchers now wonder if this ability will translate to a survival strategy as the oceans warm and acidify.
If humans want to make changes like this, we have to go back to the blueprints. We rely on DNA mutations passed to the next generation.
So what’s the cost to the octopus for the decisions of a headstrong contractor? Its blueprint hasn’t changed much in the last hundred million years.
Credit: From “Proteroctopus Ribeti in Coleoid Evolution,” by Isabelle Kruta et al., in Palaeontology, Vol. 59; November 2016
Keeping its ability to edit RNA on the fly may have stunted its own evolution.
6. If things aren’t interesting enough, they’ll eat off their own arms.
Yup. In captivity, if they don’t have enough to do because their artificial habitats aren’t full of shells, puzzles and games, they’ll cannibalize themselves out of sheer boredom. Nom nom nom nom nom.
Yes, octopuses are weird. But in some ways, they’re also pretty similar to us.
They can recognize faces. Even when scientists are dressed in identical white lab coats, an octopus can tell them apart from across the room.
They can use tools. This one even built itself a mobile home.
And they can get schooled. One octopus has learned to take pictures.
According to Frans de Waal, author of “Are We Smart Enough to Know How Smart Animals Are?” we’re making a big mistake when we don’t recognize human-like behaviors in animals. He calls it “anthropodenial.”
Don’t be in anthropodenial. Octopuses are brilliant.