What organ do sharks use to detect electrical fields?

Sharks use the ampullae of Lorenzini to detect electrical fields. These specialized electroreceptors are networks of tiny, jelly-filled canals that open through pores in the skin, especially around the snout and mouth.

Every animal produces weak electrical signals when its muscles and nerves work. In seawater, a shark can detect these signals and use them to locate prey, even when the animal is hidden in sand or darkness. This sense is particularly valuable at close range, when smell or vision may not reveal the exact position of a fish or ray.

The ampullae are named after Stefano Lorenzini, who described them in detail in 1679, although their function was not understood then. They are not the same as the lateral line, which senses water movement and vibration. “Electroreceptors” is the broader term for the sensory cells, while the ampullae of Lorenzini are the specific organs that contain them. Related organs also occur in rays and chimaeras.