Weird, bizarre, creepy, alien, shape-shifting. These are words used many times to describe octopuses. But how about intelligent, venomous, swift, playful, and sentient?
You have to agree that octopuses are pretty unusual-looking creatures. I guess that’s what makes them a great model for characters in movies like Pirates of the Caribbean. Octopuses have a lot of intriguing traits beyond their physicality. Moreover, we wonder, is this an intelligent creature? Could this be a sentient creature? Read on and find out!
Octopuses are related to other mollusks including slugs, snails, squid and cuttlefish, all having soft bodies and lacking a skeleton. But squid, cuttlefish and octopus are all cephalopods, which translates to meaning head and foot, that is having limbs attached directly to their head. Wow, how weird is that? These three species all have eight arms, but squid and cuttlefish also have two feeding tentacles. When we are lucky enough to see an octopus, it is typically seen on the reef floor near a coral head or peeking out from a crevice. Squid are most often seen swimming in schools near the waters’ surface and cuttlefish tend to hover just over a reef or alongside a reef wall.
There are around 300 species of octopuses around the world, and they are found in all of our seas. And yet, as divers, most of us always get excited when we spot an octopus, in part because we typically don’t see them often. Many are nocturnal hunters, being reclusive during the day lying hidden in coral and sponge crevices. They hunt relying on vision. Their eye is considered a single-lens-camera eye, that is, a lens that focuses an image on a retina, and capable of distinguishing brightness, size, shape and position. They see very well through those squinting eyes!
Be sure to be on the lookout for piles of broken up crab and snail shells on the ocean floor as it may indicate that a den is nearby. After all, they are carnivores, eating crabs and other mollusks. Good luck with finding them, though, because these wizards of camouflage can mimic their surroundings in a split second and, because they have no bones, can disappear into a crack little bigger than their eye! Or they can burrow into the sand. Poof, like Houdini! Where did it go, you’ll be wondering if you take your eye off of it for a second. Realize there’s a slim chance of finding an octopus if it doesn’t want to be found. Have you ever wondered how they can blend in with their surroundings so quickly and easily? The color-containing pigment cells (chromatophores) in their skin are surrounded by muscles which can contract and relax, allowing them to change their color and skin texture in seconds. This enables them to hide in plain sight from their predators. Watch this slideshow of a day octopus moving along the reef floor and see how it changes colors and textures to match the corals, anenomes, and sand where it hides!
As crazy as this sounds, the Mimic octopus can actually change body shape to resemble another animal, like a deadly lionfish, or even a flounder. Ok, I think if I were to witness this, I’d believe I was experiencing nitrogen narcosis!
Their “beaks” can deliver a nasty bite and even venomous saliva to their prey. In fact, the blue-ringed octopus is known to be deadly to humans. This is truly very hard to believe when you actually see one of these little darlings about 2-3” long, but I’m not about to test that fact.
When threatened, an octopus can produce “ink” to deter its potential predator. Inking not only creates a smokescreen, but did you know that when sprayed into a predator’s eyes, it can actually cause a blinding irritation as well as confuse the predator’s sense of smell and taste? Take that, you predator!
Not only can it ink, it is capable of jetting away backwards. It fills its mantle with water, then expels it through the siphon to create that powerful jet propulsion, reaching speeds up to 25mph!
And if all else fails in one of these nasty encounters, the octopus can lose one of its arms so that it can escape its predator, and then re-grow the arm with no permanent damage!
With nine brains, they are the most intelligent invertebrate and have sophisticated nervous systems. Their nine brains consist of one central brain and one at the base of each arm controlling movement. In fact, most of their neurons are located in their arms! Their arms have their own sensors, having the ability to sense not just touch but also smell and taste. Each sucker on their arm may have up to 10,0000 neurons to sense touch, smell and taste. And even a severed arm can sense touch, taste and move on its own without oversight from the brain! The arms literally have minds of their own!
Many studies have been done with octopuses in aquariums and have shown that octopuses learn easily, and can learn by observing another octopus. They can even learn to recognize specific human keepers at aquariums. At an aquarium in New Zealand, one octopus apparently disliked one of the staff members, and when this individual walked by, the octopus would spray a jet of water at her! (source: Godfrey) Scientists are finding that octopuses have individual responses and temperaments in a given situation; that they have personalities! Or is that octopusalities?! They are capable of solving problems, like unscrewing a jar lid. They are capable of “play”. They can be seen using “tools”, like the Coconut octopus which will “grab” a coconut shell, scuttle across the ocean floor only to then crawl inside for safe hiding. Alas, we can still see you!
Many species of octopus live only several years. As with many other creatures, the octopus’ main purpose in life is to reproduce. Octopuses reproduce only once in their lives. One of the male’s arms doubles as a reproductive organ holding rows of sperm. This is the arm without suckers on the end of it. When a male approaches a receptive female, he may either insert this arm into her oviduct to fertilize her eggs or literally take off this arm and give it to her to store in her mantle. Seriously! After mating, the male wonders off to die. If the male has given the female his arm, then when the female is ready to lay her eggs, she then takes out the arm and spreads the sperm over the eggs to fertilize them. Again, truth is stranger than fiction! The female can lay hundreds of thousands of eggs, which she will then guard obsessively while she stops eating. Depending on the species, it may takes anywhere from 2-10 months for the eggs to hatch. Then, after they hatch, the female’s body biologically shuts down and she dies. How sad. The hatchlings are then on their own quickly learning how to hunt, either drifting along ocean currents or settling to the bottom.
There’s a lot of debate on the correct plural form of “octopus”- is it octopuses, octopi or octopodes? It seems there are several schools of thought. The word “octopus” comes from Greek and being consistent with the word’s origin, plural would be “octopuses”. If you’re talking about several species of octopus, some say that the correct plural is “octopi”. I don’t know about that. If only octopus could speak (our language), I’m sure they would tell us.
Some people find octopus to be a gourmet delicacy. I admit; I tried it once or twice as sushi. Nope, not for me. I’d much rather see the antics of an animated octopus underwater, crawling around on the reef floor, its body morphing and camouflaging with its surroundings.
With brains in arms and shape-shifting abilities, it seems like the octopus was conceived through science fiction. We know that sometimes truth is stranger than fiction, and so it seems with octopuses. It seems that all of those descriptors listed above can be fitting – weird, bizarre, creepy, alien, shape-shifting, intelligent, venomous, swift, playful and sentient. Be sure to enjoy watching an octopus the next time you see it, whether you are at an aquarium, diving or snorkeling and marvel at its unique qualities. I hope that through continued research, more fascinating and bizarre characteristics will be discovered about them!
(1) Peter Godfrey, “Mind of an Octopus”, Scientific American, Jan 1 2017
You can read about more fascinating studies and theories about the mind of an octopus here:
https://www.scientificamerican.com/article/the-mind-of-an-octopus/