Sciency Words: Chromatophore

Today’s post is part of a special series that first appeared on Planet Pailly. Every Thursday, we take a look at a new and interesting scientific term to help us all expand our scientific vocabularies together. Today’s word is:


Chromatophores are special cells in the skin of some animals, most notably the squid and the chameleon. These cells contain pigments. When stimulated by hormones, muscle contractions, or other mechanisms, chromatophores expand or contract, changing the animal’s skin color.

There are several different kinds of chromatophore, depending on their hue:

  • Erythrophores contain red pigment.
  • Xanthophores contain yellow.
  • Cyanophores contain blue.

As I’m sure you can guess, different combinations of cells can produce almost any color of the rainbow. Other chromatophores contain shades of black or white or can make the color look shinier.

Most animals use chromatophores for camouflage, but some species of squid may actually use rapidly changing colors as a form of communication. I’d guess their language consists of little more than phrases like “Danger!” “Food this way!” and “Wanna hook up?” Which are, to be honest, the only things worth saying anyway.

What we learn about chromatophores could be useful for helping us understand extra terrestrial life. It could also help us Sci-Fi aficionados design our own alien species. It’s important to remember that verbal language isn’t the only possible form of communication—not even here on Earth.

Written by James Pailly.

To read all the articles in the ‘Sciency Words‘ series, visit the Planet Pailly blog.

  • John H Reiher Jr

    Whats more remarkable is that squids and all cephalopods are color blind. So how do they know what color they are making? Some biologists think that the skin of the squid can detect color around it. So the squid can see with its whole body when it comes to color.

    • James Pailly

      Wow, I hadn’t read that before. That opens up an even wider range of possibilities for science fiction. If squid communicate neither with ears nor eyes but through an entirely different sensory experience, just imagine how many ways extraterrestrial life might “speak.”

      • Paulo R. Mendes

        Well, the creatures in “Alien Planet” can use sonar and photophores (and as far as I know, they don’t have vision! their “sonar sense” replaces their eyes) to communicate between themselves…imagine how they perceive the world around them. Those must be minds really alien.

        • Not as alien as you might think. Bats use echo location to navigate in the darkest caves. They also use it to communicate danger and in mating.
          And communicating with “Sonar” is technically an acoustic form of communication…or exactly what we do. (A blind man still can hear and speak so eyes are not essential as you might think in communication)

          • Paulo R. Mendes

            Yes, but I think that is a bit too odd creatures without (?) vision using photophores to communication – it is like to try to use signposts to communicate with blind people.

            • well communication is a strong word.But you process light without eyes. Your skin is light sensitive.Not only does it have pigments that change the color of your skin,

              but is associated with the production of B12 vitamins. Which in turn affect your mood and thus your emotions and emotional responses.

              Before digital photography there was “chemical photography” the film medium used is light sensitive (as a matter of fact even digital cameras do not have eyes, but have light sensitive receptors)

              Even a blind man could get depressed in the long month of Arctic night.

              Light is absolutley neccessary for almost all creatures on Earth [1] be it plant or animal.

              So while those squids do not see color they do see light and their epidermis contain light sensitive cells.(The cell color determines to what wave length btw) So while it is

              amazing it is neither magic nor unexplainable.

              I mentioned Black and white film and TV. Your brain automatically associates the many shades of gray to colors. The lips of a woman in a black and white movie are still “red” to your mind.

              Your brain associates known parameters and “fills” the gaps. (to some extend of course) It is fair to assume that the chameleon or the squid use a similar process to evaluate shades of gray. Most likley there is no

              thought process involved, but it uses neuron signals of lumi sensitve nerves within its epidermis to adapt to its environment or react to genetic pre determined responses to such stimuli.

              There are a host of functions in your body you have no influence over.Such as body temperature, heart beat, non cognitive responses to stress and danger.

              You get goose bumps when frightened…the hair of your once body covering fur stand up. This is a non cognitive signal. A dog or wolf (or ape) signals its enemy.”I am bigger than I look”

              The position of ears, the way a tail moves, exposed teeth…in a dog or cat are all signals and part of non cognitive genetic based signalling.

              even your glands start producing pheromones that can be detected by an olfactory sensitive being.(Such as a dog)

              [1]The true aliens on our planets are the animals and organisms existing in ocean trenches near black smokers / hot vents. who live without light – and replaced their body chemistry from photo to chemical synthesis.

      • John H Reiher Jr

        There’s a great video of a squid trying to woo a female squid with a display on one side of his body and warning off another squid with his other side! Sadly, I can’t find it to share. My Google Fu is weak tonight.

    • But they do have sight. Watch an old back and white movie. It simulates colors in shades of gray.Also it is suggested that these squids and their cephalopod friends do have photo reactive cells able to differentiate the wavelength of the reflected light.
      A squid can not change color in a light less environment and surprisingly it works only in the visible light band,not with Infrared or Ultraviolet light.

      • John H Reiher Jr

        Yes, they have sight, but they can’t see colors. But it seems that their skin can.

  • How about communication with light? Fire flies
    Ants – molecular scents
    Bees – dance to communicate quite complex information
    Rabbits – use vibrations to communicate (Thumper in Bambi was very aptly named)
    Sharks not only locate their prey sensing electric pulses but it is suggested they communicate with their lorence organ to coordinate attacks.

    Did you know that Quantum physics defines the smallest possible thing in all the Multiverse, not as some super exotic particle, but as information? The Bit ,the status of 1 .It makes up the so called “Quantum foam” and this information makes up everything. Put’s a whole new meaning to Genesis by the way as the Creator uses words (information) to create or alter conditions.

    The way bio organisms change colors to achieve adaptive camouflage is a hot topic in military research labs. DuPont and GE are supposedly working on a bio film that does exactly what the squid skin does.

    In a much less complicated technology there are dresses (fabric) that display the wearers mood. It adds a whole dimension of communication and information exchange to humans.
    I personally envision the PMS dress to be the hottest seller in 2030 and the nightmare of all the poor guys out there.

    • James Pailly

      That’s an interesting take on Genesis. I never thought of it that way.

      That’s also an interesting take on fashion, and again… I never thought of it that way.

      • After centuries of wondering, men can finally work out if their partner really is ‘fine’ or not thanks to a new dress that changes colour depending on a woman’s mood.

        The Bubelle Dress is made up of two layers, the inner layer contains biometric sensors that pick up a person’s emotions and projects them in colours onto the second layer, the outer textile.

        The sensitive dress, which was designed by electronical giants Philips, works by monitoring physical changes associated with different feelings.

        Emotions such as stress, arousal, or fear affect the body’s temperature and sweat levels and these generate the light that changes the pattern and colour on the dress.

        Ingrid Bal from Philip’s Design said: “You could programme the material so that it turned red if you were angry or stressed, or green when you’re calm.”

        Should the prototype ever hit the high street it would help British couples to communicate better.

        It was developed as part of the SKIN Probe Project, a research programme concerned with what lifestyles might be like in 2020. Time magazine named the impressive clothing as the best fashion invention of the year.

        Ms Bal said: “We were interested to see how technology may affect our lives in the future and to provoke debate. We are asking: ‘Would the idea of emotional clothing be something we will wear in 10 years time?'”

        Scientists at the Dutch firm have also designed emotion-sensitive electronic tattoos as part of their design project.

        A spokeswoman said: “In much the same way as make-up is put on and taken off to suit the occasion, a tattoo could alter whenever desired.

        “The tattoos could even change in response to gestures or emotions.”

      • Despite the fact that I am a science and SF geek. It also happens I am a member of the female part of society and we tend to be interested in fashion and dresses. So no worries I doubt you are frequenting fashion sites and have a subscription to Harper’s Bazaar and Vogue..;-)

    • Kirov

      Your comment on Genesis reminds of The Last Question by Asimov. Great story.