Sydney, Jan 11 (IANS): Shark pups in embroys play dead in a predator presence, literally holding their breath and becoming still, shutting down their own electric field, says a research.

Adult sharks are known to use highly sensitive receptors to detect electric fields emitted by potential prey.

Researchers found that embryos of some shark species employ similar means to detect potential predators and escape being eaten.

"This knowledge may help us to develop effective shark repellents," said Ryan Kempster, marine neuroecologist at the University of Western Australia's (UWA) Oceans Institute, who led the study, the journal Public Library of Science ONE reported.

"Despite being confined to a very small space within an egg case where they are vulnerable to predators, embryonic sharks are able to recognise dangerous stimuli and react with an innate avoidance response," added Kempster, according to a statement of the UWA Oceans Institute.