Spooky Crabs Darken Camouflage From Day to Night
Horned ghost crabs change their camouflage from day to night.
Credit: Martin Stevens

Some teenagers like to stand out with wild hairstyles and flashy clothes, but young horned ghost crabs prefer to blend into the background.

Juvenile crabs mimic daily changes in their environment, shifting their coloring from day to night, new research suggests. When the sun's bright at noon, the crab's light carapace matches the yellow beach sand in their Singapore habitat. At night, the crabs are darker, to better blend in with the shadows, lead study author Martin Stevens of Exeter University told the BBC.

Stevens noted the crabs react to the daily wax and wan of sunlight, not to shifting shadows, because a dark crab scuttling from a cave during the day would make easy pickings for predators. Only juvenile crabs shift their camouflage so dramatically, Stevens said. The study appears in the April 2 issue of the Biological Journal of the Linnean Society.

Read more: Martin Stevens' research group

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