An octopus is a master of camouflage, but when danger lurks and it becomes clear that blending in with its surroundings is not working, an octopus can also shed its camouflage.

This amazing and rarely observed phenomenon was videotaped recently by Jonathan Gordon, while he was snorkeling in the Caribbean.

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In truth, Gordon was fooled by the octopus before it sensed his presence—more likely that of his camera lights—and suddenly turned a brilliant blue, taking on the appearance of some sort of alien blob.

"I dove down to have a look at the shell that you can see just under where the octopus appears and as I approached the octopus came out of hiding," Gordon writes in the video description (the GIF posted below is courtesy of the Daily Telegraph). "I had literally no idea he was there until I was about a meter away."

But the octopus felt as though it needed to lose its camouflage, and to instead issue a warning, and responded accordingly.

Octopus_camouflage_3187597aThey're capable of changing colors in an instant thanks to thousands of color-changing chromatophore cells that contain tiny sacs of pigment.

The Smithsonian Museum of Natural History explained on its "Ocean Portal" blog: "The center of each chromatophore contains an elastic sac full of pigment, rather like a tiny balloon, which may be colored black, brown, orange, red or yellow. If you squeezed a dye-filled balloon, the color would be pushed to the top, stretching out the surface and making the color appear brighter—and this is the same way chromatophores work.

"A complex array of nerves and muscles controls whether the sac is expanded or contracted and, when the sac expands, the color is more visible."

Changing colors also is performed as a means of communication among cephalopods, and in Gordon's case the message seemed clear enough: "Don't come any closer, or else!"

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