Movie S1.

Octopus vulgaris showing dynamic background color matching in the wild. The first segment of this clip shows O. vulgaris in shallow water camouflaged against a green clump of algae. In the second segment, the same species rapidly changes to a matching color when faced with a reddish/brown natural background. Additional examples of camouflaging are in Fig. 1 and Fig. S1. Movie courtesy of Roger Hanlon.