KQED’s ‘Deep Look’ Explores How and Why Squid and Other Cephalopods Change Color

The most recent episode of the KQED science series “Deep Look” explores the reasons why and the manner in which cephalopods change color, noting that squid use a completely different system to camouflage themselves.

Octopuses, cuttlefish and squid belong to a class of animals referred to as cephalopods. These animals, widely regarded as the most intelligent of the invertebrates, use their color change abilities for both camouflage and communication. Their ability to hide is critical to their survival since, with the exception of the nautiluses, these squishy and often delicious animals live without the protection of protective external shells. But squid often live in the open ocean.How do you blend in when there’s nothing — except water — to blend into? They do it by changing the way light bounces off their skin — actually adjust how iridescent their skin is using light reflecting cells called iridophores. They can mimic the way sunlight filters down from the surface. Hide in plain sight. Iridophores make structural color, which means they reflect certain wavelengths of light because of their shape.