Cuttlefish (Sepia officinalis) are masters of camouflage. Not only can they change the color and pattern of their skin, but they can shift their bodies to mimic just about anything. Researchers want to use this ability to develop better camouflaging materials.
Cuttlefish have been living in the oceans for more than 500 million years. Their cephalopod ancestors were protected by hard shells, but modern cuttlefish don’t need a shell because they can avoid predators by hiding in plain sight.
A 2011 study by Roger Hanlon was the first to confirm that cuttlefish use visual cues to determine what posture to adopt in order to avoid predators. In fact, they’re so good that they can mimic something just by looking at a picture of it.
Cuttlefish have more than 20 million chromatophores in their skin. Chromatophores are cells of pigment that are attached to tiny muscles. By flexing or relaxing those muscles, the cuttlefish can alter the color of its skin — it can even flash different colors when competing for a mate.
Researchers have long known how a cuttlefish changes its appearance, but the exact biological, chemical, and optical functions that make it possible remained unclear. Now, new research from Harvard University and the Marine Biological Laboratory (MBL) reveals how it works.
In addition to the chromatophore, cuttlefish also rely on the leucophore (a light-scatterer), and the iridophore (a reflector) to regulate its color. The combination allows the skin to “selectively absorb or reflect light of different colors.”
The researchers hope that a better understanding of cuttlefish camouflage will lead to the development of improved camouflage for soldiers’ uniforms. The next challenge will be to replicate the system synthetically, but we’re not quite there yet. When the cuttlefish changes color, the surface area of the chromatophores can expand up to 500 percent and researchers are not currently able to engineer materials that have the ability to expand that far. But when they can, the technology could be applied to paints, cosmetics, and even electronics.
You can read the full study here: The structure–function relationships of a natural nanoscale photonic device in cuttlefish chromatophores.
To see some cuttlefish in action, check out this National Geographic video, World’s Deadliest: Sudden Death Cuttlefish.
And for even more, watch PBS’s Kings of Camouflage.
Copyright © 2014 by Marine Science Today, a publication of Marine Science Today LLC.