Lone changer: fish camouflage better without friends nearby

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While gobies aren't the only fish with camouflage abilities, new research shows that their colour change is influenced by their social context: they transform faster and better when alone. This is likely an adaptive, stress response to perceived threat from predators - with possible application to other camouflaging species.
Fish feel calmer and more secure in groups: have less need to hide

It's like a half-hearted dress up party: gobies don't camouflage completely in groups, new research finds. They change colour to avoid detection by predators and do so faster and better when alone.

In the research, published in Royal Society Open Science, University of Sydney academics suggest this is because lone fish are more vulnerable. They add that camouflage has a metabolic cost, so gobies likely preserve this energy when, due to safety in numbers, they don't need it as much.

"Grouping behaviour can reduce stress in fish, partly because they are in less danger of attack by predators. This 'safety in numbers' effect may allow them to change colour more slowly without added risk," lead researcher Miss Stella Encel said.

"Since stress hormones like cortisol and adrenaline are central to the neurological mechanisms of colour change in fish, it's possible that stress levels also directly affect their ability to camouflage."

The presence of other individuals having a calming effect is known as 'social buffering'. It has wide-reaching…
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