Octopuses are known for being incredible escape artists, able to disappear into the smallest cracks, but they are also masters of camouflage. They, and other cephalopods (like squid and cuttlefish), are able to change the color of their skin to match their surroundings; no need for painted long-johns!
These animals use specialized cells, called chromatophores, that each hold a different pigment (yellow, orange, red, brown, or black). The octopus can expand or contract these cells, like a balloon, to push the color to the surface of the skin (check out the Smithsonian’s Ocean Portal for more info.) and make that color more visible. Different colors are used to create patterns that mimic the environment around the octopus, almost making it disappear.
Not only can an octopus change the color of its skin, they can also change the texture.
Octopuses have bumps on their skin called papillae and these bumps can be changed into spikes, ridges, or smoothed out. Scientific American’s article “How the Octopus Creates Instant 3-D Camouflage on Its Skin” can tell you more about how this is accomplished.
So with the ability to change color and the texture of their skin, octopuses can blend into almost any surface. They use these skills to hide from predators as well as sneak up on prey. And if hiding doesn’t work an octopus may use “startle behavior”, aka flash a color and expand their bodies to make themselves look larger, and hopefully scare or surprise a predator so the octopus has a few more seconds to escape. While on a night dive in St. Johns, I also saw an octopus flash when hunting. It snuck up, flashed white and then blue as it expanded itself (like a parachute) to capture its prey.
Check out the images below to see if you can find the octopus!