Shark Fetuses Detect Predators’ Electric Fields
Baby sharks still developing within leathery egg cases can sense the electric fields of predators and freeze in place to avoid detection, researchers say. These findings could help in developing more effective shark repellents, said scientists who detailed their findings online in the journal PLOS ONE.
A number of species of sharks deposit embryos in rectangular capsules once whimsically called mermaid’s purses or devil’s purses. These egg cases often possess long tendrils at each corner that help anchor them to surfaces. The shark parents of these embryos use highly sensitive receptors known as the ampullae of Lorenzini to detect the electric fields generated by the muscle contractions of potential prey. Now scientists find their embryos can similarly detect the electric fields of potential predators to help them escape being eaten.