More camouflage today–this time from the cephalopods. Red octopuses ran rampant at Catalina Island last weekend, scavenging on the discarded squid egg cases littering the seafloor. As they passed over kelp, seagrass, sand, rubble, and the egg cases in various shades of white and brown, the octopus changed color, their skin color and texture shifting to blend the animal into its surroundings.

The following set of photos follows one “red” octopus as it traversed the seafloor and attempted to conceal itself from me:

How do Octopuses Change Color?

It turns out that octopuses, as well as other cephalopods (such as squid and cuttlefish), possess color-changing cells in their skin called chromatophores. Each chromatophore contains a sac filled with red, orange, yellow, black, or brown pigment, and the octopus’ nervous system is able to manipulate these pigment sacs to make certain colors more or less visible.

Changing color isn’t the octopus’ only method of concealment: the octopus can also alter the texture of its skin. By changing the size and shape of lumps on its skin called papillae, the octopus can mimic not only the color, but the texture of its surroundings for a more effective camouflage.

However, concealment does not appear to be automatic. This red octopus didn’t seem at all threatened by my presence, and even seemed to pose for a few photos (although the shot of it behind the squid egg case reminds me all too much of the moose in New Hampshire):