Rapid color change used for protection: cuttlefish
The skin of cuttlefish changes color rapidly, in order to evade predators, using elastic pigment sacs called chromatophores.
|Biomimetic Application Ideas|
|Biodegradable video screens for electronic devices; eliminate toxic pigments in commercial coatings and products, including paints, textiles, paper, and building products; flexible solar shading or coatings for buildings.|
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"That said, cuttlefish are not above acknowledging the presence of lesser species such as humans, as divers around the world will testify. When they come across cuttlefish, some divers offer a greeting, the two-fingered "peace" sign. In what is surely one of the few cross-species salutations in the natural world, the cuttlefish reciprocates by lifting two of its arms. This message of peace is actually quite the opposite - a startle response to what the cuttlefish perceives as a threat. Sticking two fingers up at divers or predators is a secondary level of defence which cuttlefish use on the rare occasions that their camouflage fails.
"Cuttlefish and their fellow cephalopods - octopuses and squid - are masters of disguise, able to turn from completely invisible to totally obvious, and back, in about 2 seconds. They can use this trick to blend seamlessly into any natural background and will have a good stab at artificial ones too. While the skills of octopus and squid are not to be sniffed at, the cuttlefish is the king of cephalopod camouflage, according to Roger Hanlon of the Woods Hole Marine Biological Laboratory in Massachusetts. The fact that it achieves its disappearing tricks with a rigid cuttlebone, which means it cannot contort its body like an octopus, only makes it more impressive.
"Cephalopods have such remarkable camouflage primarily because of their chromatophores - sacs of red, yellow or brown pigment in the skin made visible (or invisible) by muscles around their circumference. These muscles are under the direct control of neurons in the motor centres of the brain, which is why they can blend into the background so quickly. Another aid to camouflage is the changeable texture of cuttlefish skin, which contains papillae - bundles of muscles able to alter the surface of the animal from smooth to spiky. This comes in pretty useful if it needs to hide next to a barnacle-encrusted rock, for instance.
"The final part of the cuttlefish's camouflage portfolio comes from leucophores and iridophores, essentially reflecting plates that sit underneath the chromatophores. Leucophores reflect light across a wide range of wavelengths so can reflect whatever light is available at the time - white light in shallow waters and blue light at depth, for example. Iridophores combine platelets of a protein called reflectin with layers of cytoplasm to produce iridescent reflections rather like those of butterfly wings. Iridophores in other species, like some fish and reptiles, produce optical interference effects that shift the light towards blue and green wavelengths. Cuttlefish can turn these reflectors on or off in seconds to minutes, controlling the spacing of the platelets to select the colour. They can also combine these iridescent hues with those of the chromatophores to make shimmering purples and oranges, for example." (Brooks 2008:28)
Organism/taxonomy data provided by:
Species 2000 & ITIS Catalogue of Life: 2008 Annual Checklist
Application Ideas: Biodegradable video screens for electronic devices; eliminate toxic pigments in commercial coatings and products, including paints, textiles, paper, and building products; flexible solar shading or coatings for buildings.
Industrial Sector(s) interested in this strategy: Electronics, textiles, automotive, paper, paint, buildingOptical metamaterials - Displays, patterned materials, sensors
Woods Hole Marine Biological Laboratory