Put a cuttlefish on one point—or, to be more exact, on a series of points—and it’s gone. These relatives of the squid and octopus mimic their surroundings, camouflaging themselves inconspicuously among seaweed, sand, or stone, helping them escape predators.
But no one knows for sure how the brain of a cuttlefish takes what the eyes see and gets the muscles in the skin to copy it.
In an effort to answer this question, scientists have turned to high-resolution video that can show what individual skin cells do when a cuttlefish changes color.
In a new study published in Nature, researchers found that cuttlefish tried various options as they worked to match their skin to their environment. As they got closer to a match, they would pause their transformation, as if checking to see if they had got it right this time. The findings are a glimpse into what is happening in a fundamentally different way of life doing something that, to our eyes, seems almost magical.
To match their surroundings, cuttlefish employ a series of pigment-filled skin cells called chromatophores and raised structures called papillae. Cuttlefish contract countless tiny muscles that open and close chromatophores, like pixels on a screen, to get the correct pattern of whatever surface they swim over.
Research has established that cuttlefish can reach their final standard in less than a second. It’s possible, thought Gilles Laurent, a professor at the Max Planck Institute for Brain Research in Germany and an author on the new paper, for the cuttlefish to see an image, decide how it’s going to imitate it, and then go directly to a skin-pattern match.
For the study, the team featured 30 sepia-printed fabric backdrops at the bottom of their tank. As the animals changed color and pattern, the cameras watched, and when the researchers analyzed the data, they saw that each cuttlefish was working with different patterns.
“What we observed is that the animals move slowly intermittently towards that final pattern, in segments of movement, interrupted by moments when they stop and seem to compare themselves with the final goal they want to achieve,” Laurent said. “When they get to something that satisfies them, they stop.”
The little pauses get longer as the cuttlefish gets closer to the final goal. “We think they have some knowledge of the pattern that they are expressing at any given time,” she said. “How that is acquired, we don’t know.” It may be that they are using their eyes to check their coloration. But it could also be that the cuttlefish is looking for a certain sensation on its skin. No one is sure of the answer.
By: VERONIQUE GREENWOOD
BBC-NEWS-SRC: http://www.nytsyn.com/subscribed/stories/6807639, IMPORTING DATE: 2023-07-17 19:20:07
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