The vanishing octopus is back. This stunning cephalopod, caught on video by Roger Hanlon, a senior scientist at the Woods Hole Marine Biological Laboratory, has been making the rounds online again. The spectacular camouflaging act, made popular by ocean explorer David Gallo's 2007 TED Talk, captures some of the octopus's most impressive transformations.
In the video, a startled common octopus (Octopus vulgaris) goes from perfect disguise on a plant, to a bright white inking projectile and finally to a large mottled pancake on the seafloor. "It was a eureka moment, there's no doubt about it," Hanlon told NPR's Science Friday. And that is quite a statement for someone who has been studying these animals—and their vanishing skills—for decades.
Although rare on film, this behavior is a quintessential feature of the octopus's defense strategy. Possessing no hard shell, claws or even teeth, the slinky invertebrate must rely on other tactics to keep from getting eaten. And it has taken camouflage to the extreme.
The octopus's camouflage is created by a trio of specialized mechanisms in their skin. The first and most well known are the chromatophores, small sacs of different colored pigment that can expand or contract changing the animal's overall hue and pattern. Augmenting that are irridophores, which can reflect light and also lend coloring to the display, and leucophores, white cells that provide a crisp background. And on top of all of that, muscles under the octopus's skin can create textures to match its environment, hence the ripply appearance at the start of the video.
There is just one hitch in our understanding of this capability: we don't know if these animals can perceive color. Lab research suggests their eyes are colorblind. Try camouflaging against a crazy coral reef when all the whites, yellows, pinks and greens are just varying shades of gray.
Hanlon and his colleagues are searching for other ways they might be able to pick up on their environment to inform their full-color camouflage. One possibility? That they can see with their skin.
Illustration courtesy of Ivan Phillipsen