Invisibility Achieved: The Humble and Amazing Octopus
Every child has entertained fantasies about invisibility. The ability of moving from place to place without being noticed; and gaining access to all manner of opportunities without any sort of detection is just the sort of stuff children dream of (as well as a few quixotic adults). Films and literature exploit this desire through tall tales of invisibility cloaks and spells that render the protagonist (and sometimes the villain) all but invisible to the naked eye, as well as potential threats. Without a doubt, invisibility is about the coolest thing anyone could wish for but alas, it is neither practical nor attainable. About the best thing we could wish for is really good camouflage.
OK, I am well aware that this is a blog dedicated to the subject of parenting and not the spuriousness and pipedreams of someone hoping to become invisible. But I could not think of a better way to cultivate a sort of wonder and appreciation for the astounding camouflage abilities of the lowly cephalopod, the octopus.
Now for most children sharks and whales are far cooler, and far easier to identify with, than the spongy, soft bodied, octopus that just seems to lurk about hoping to remain inconspicuous. But it is this remarkable inconspicuousness that makes the octopus, not only fantastic, but also all together otherworldly (not to mention their amazing ability to predict the winner of the World Cup eight times in a row).
There are probably countless things I could say about the humble octopus that would impress you, but for the sake of brevity I will stick to the topic of camouflage (or invisibility, depending on how you want to look at it). The octopus’s camouflage is aided by certain specialized skin cells, which can change the apparent color, opacity, and reflectiveness of the skin (something called chromatophors). Cephalopods (which include both the octopus as well as the cuttlefish) have huge eyes, and much of their brain is dedicated to processing visual information. They use this information to control their disguises through a dense network of nerves running from the brain to the skin. Their color-changing talents, while most often used to hide from predators or would-be attackers, can also be used to communicate with or warn other octopuses. They can deftly, and instantaneously, use muscles in the skin to change the texture of their mantle to achieve a greater camouflage. In some species the mantle can take on the spiky appearance of seaweed, or the scraggly, bumpy texture of a rock, among other disguises. Because they are such a vulnerable sea animal (soft bodied, no armor, and a chewy snack for many) it is essential for the octopus to develop, and exploit, their camouflage abilities to simply stay alive.
Roger Hanlon, a senior scientist at the Marine Biological Laboratory, has watched octopuses perform what he calls the Moving Rock Trick. As reported in 2008 in the pages of the New York Times, they assume the shape of a rock and move in plain sight across the sea floor. But they move no faster than the ripples of light around them, so they never seem to move. They also hold the amazing ability to go from a state of relative static invisibility (or to be fair, camouflage) to a quick getaway (see video below).
Experiments with various octopus species have revealed that, while their skin changes rapidly to any hue within the rainbow at a moments notice, the octopus is essentially colorblind. Go figure?
If nothing else, the acute and wildly impressive camouflage abilities of the octopus should not only invoke a sense of wonder, but cultivate a deep appreciation of the hidden (literally and figuratively) genius of the natural world.