Fish discovered camouflaging itself with smell
The harlequin file-fish is the first vertebrate discovered using the
trick
Blending into the background by way of visual camouflage is pretty
old hat by this stage with animals rendered more or less invisible to
predators by a vast array of fur coats, feathers, shells and skins.
But nasal camouflage, the practice of disguising yourself against the
enemy by smelling like something of far less interest, is uncharted
territory. That may be about to change, however, after new research
discovered that the harlequin file-fish adopts the smell of the coral it
eats to hide from predators - raising the prospect that the survival
technique could be widespread among all manner of animals. Until now,
smell-based disguises were only known to exist in a handful of smaller
invertebrates, but this is the first time it's has been located in a
larger vertebrate species.
"For many animals vision is less important than their sense of
smell," said author Dr Rohan Brooker, from James Cook University in
Australia.
"Because predators rely on odours to find their prey, even visually
camouflaged animals may stick out like a sore thumb if they smell
strongly of 'food'.
By feeding on corals, the harlequin file-fish ends up smelling enough
like its food that predators have a hard time distinguishing it from the
surrounding coral habitat," Dr Brooker said.
"This is very exciting because it opens the possibility of a wide
range of different animals also using similar mechanisms, right under
our noses," he said.The file-fish matches the colour of the coral so
closely that small crabs, which lived on the coral branches, couldn't
distinguish it from the coral.
However, their cover is blown if it shelters in a different species
of coral than the one it has been eating, the report cautions.
- The Independent
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