Cuttlefish… octopuses… and squid have
an almost otherworldly ability to control their appearance. What makes it possible are these spots. They’re called chromatophores. They’re
like tiny water balloons, filled with colored pigment. When the balloons expand, you see more pigment,
more color… When they contract, the color shrinks to a
tiny dot. The overall effect can be really dramatic. And for good reason. These animals don’t have protective external
shells. They’re unarmored. Naked. And they aren’t great swimmers, either. Camouflage is their best defense. They have
to be good at it. Octopuses can change their body position and
the pattern on their skin to match rock or coral. Octopuses and cuttlefish can even change the
texture of their skin to throw off predators. Become bumpier and more rock-like. But squid often live in the open ocean. How
do you blend in when there’s nothing — except water — to blend into? They do it by changing the way light bounces
off their their skin — actually adjust how iridescent their skin is using light reflecting
cells called iridophores. They can mimic the way sunlight filters down
from the surface. Hide in plain sight. So how do they control all this color change? Is it voluntary or some kind of built in reflex? That’s what researchers at Stanford University
wanted to know. So…they anesthetized the squid and then
snipped the nerve from the the brain that controls the chromatophores, but only on one
side of the animal. The brain essentially couldn’t send messages
to the tiny muscles that control those chromatophores anymore. … almost like turning off a light switch. But after a few days, then they noticed something
strange. The chromatophores began blinking again…
even though they were no longer getting signals from the brain. So what does this mean? Well, what it suggests is that color change
might be a bit like breathing is for humans. Something we can either choose to do… or
do automatically. Only… even cooler — because unlike breathing,
color change requires an awareness of your surroundings. And in these animals, that awareness is spread
throughout the skin… as if the skin itself could see. It would be as if your skin knew what color
the walls were, even with your eyes closed. For a soft and squishy creature trying to
stay alive in a very big ocean — it’s a pretty spectacular defense.