One of my greatest loves in the animal kingdom is the cephalopods family. They are an amazingly diverse groups of creatures with around 800 different species, which include octopuses, squids, and the little known cuttlefish. Much like alligators, snapping turtles, and hagfish, cephalopods have remained nearly unchanged for around 438 million years. Many cephalopods are capable of complex cognitive tasks, can learn complex associations and a few captive specimens have been known to consistently escape their aquarium habitats. But for me their most impressive trait is their ability to change the color and shape of their skin in order to camouflage themselves in nearly any environment.
They achieve this by contracting and expanding special pigment sacks in their skin cells – called chromatophores - to create different colors. These contractions and expansions can occur in isolated areas, or across the whole animal, effectively giving cephalopods an infinite range of color combinations and patterns. They can do this extremely fast. Some species of squid and cuttlefish even use flashing colors to mesmerize their prey, immobilizing them, before they strike.
Along with these color cells some squids have an additional layer of iridescent cells beneath their chromatophores called iridophores. Unlike most colors we see, which are caused by pigments absorbing and reflecting certain wavelengths of light, iridescence is caused by structures interfering with the reflectance of light, causing the wavelengths to interact with one another and creating intense, almost metallic hues. The squids use special nerve pathways to break up or reform these iridescent structures in order to give their skin iridescence on queue! Unlike the very fast changes seen in chromatophores, however, the alteration in iridophores moves more slowly, cycling through the rainbow from red to blue over a period of about 15 seconds.
I also found this neat video made by Creature Cast, a podcast about nature, which explains how squids change color.
I find this ability absolutely amazing! I wish I had the power to basically glow or turn a million different colors on queue. Having said that, it does present some very interesting Biomimicry angles to work from:
- Understanding and mimicking cephalopod’s ability to change the hue of the their skin could be used for peace-keeping uniforms and exploratory wear to help soldiers or scientists better camouflage themselves.
- Paints could be developed that change hue in order help regulate heating and cooling for homes and buildings.
- Self-colorizing windows or glass in general could be developed to make the world a more beautiful place, set the tone in healing environments, make exhibitions more dynamic.
- Or maybe everyday clothes could use change shade or consistency so fabrics would breath better or protect us form the sun.
All these are just ideas, but I hoped you learned, or liked something! These animals are truly amazing and I will be adding them to my list of animals to study and mimic in the future!