Cuttlefish evade predators by matching not only their colours and patterns to the background, but also their postures.

Roger Hanlon and his team at the Marine Biological Laboratory in Woods Hole, Massachusetts, presented the common European cuttlefish (Sepia officinalis; pictured left) with separate backgrounds containing stripes at different angles: horizontal, vertical, and diagonal. The animals raised their limbs to match the angles of the stripes, but didn't respond to a blank background.

When placed next to artificial algae in the lab, the animal struck a pose to mimic its neighbour (right). Similar behaviour was observed in natural habitats. The authors suggest that visual cues are important for such creatures to adopt cryptic body postures and achieve maximum stealth.

Credit: J. J. ALLEN

Proc. R. Soc. B doi:10.1098/rspb.2011.0196 (2011)