Cuttlefish are often thought of as the masters of camouflage in the animal kingdom and scientists have documented a skill that could make them more invisible to predators – not breathing.
Sharks, which use an electric sense to find prey, are one of the main hunters of cephalopods such as cuttlefish. The skill, called electroreception, can still be effective even when prey can't be seen.
It allows sharks to detect weak bioelectric fields produced by marine organisms as they breathe out into the electrically conductive salt water.
But a new study by Dr Christine Bedore from Georgia Southern University published by The Royal Society today found cuttlefish reduce their bioelectric signals by "essentially holding their breath".
She says it could act as an extra method of camouflage when hunted by predators.
The freezing behaviour often happens at the same time as physical camouflage to help escape from predators, which use visual and non-visual methods to hunt.