When it comes to blending in, cuttlefish are like chameleons of the sea. In fact, their color-changing and shape-shifting feats are far better than those of the chameleon, as they can change their appearance almost immediately. They can even alter the texture of their skin to mimic the textures of the corals, rocks, and plants around them.
Cuttlefish — which aren’t fish, but rather cephalopods, like octopuses and squids — have long amazed and bemused scientists for their unparalleled camouflage and intelligence. Researchers have begun to unravel the mysteries of these creatures, and have now identified the neural mechanisms that give them their incredible shape-shifting abilities.
In a recent study published in the journal iScience, the research team explored how cuttlefish skin is made up of two types of small muscular organs, and how these organs are connected to its nervous system. One type, known as “chromatophores,” receive signals from the brain, directing them to change color. The other organs can be controlled to create nipple-like protrusions, called “papillae,” along the cuttlefish’s skin.
In their study, the researchers revealed just how the instructions for the cuttlefish camouflage are sent from the animal’s brain, through its peripheral nerve center, and to its specialized muscle organs. The nerve circuitry they uncovered mirrors that found in squids, which enable them to make their skin iridescent.
“Cuttlefish are able to hold their papillae without sending neural signals — this is very different to most muscles — and the circuit that controls papillae is very different to the chromatophore colouration pathway, meaning it evolved differently and potentially uses skin sensors to direct its activity,” University of Cambridge researcher Trevor Wardill, told Digital Trends. Wardill analyzes skin signaling in cephalopods and is the lead author of the recent study.
Cuttlefish still have their fair share of secrets, however. One of their most perplexing talents is their ability to interpret their surroundings and change their appearance accordingly. Nonetheless, Wardill thinks his team’s recent research will help inform biomimetic structures and materials that can adapt to their surroundings, just like the cuttlefish.
“[This] research will inspire products that could mimic the texture and shape of their surroundings,” he said, “but also may find medical application due to their soft actuator capabilities. Currently we cannot build anything like a papillae that can change from entirely flat to various 3D shapes within one second and remain flexible.”
