Dolphins Have a Seventh Sense: Electrosensitivity!

A study conducted at the Nuremberg Zoo, Germany, on two female bottlenose dolphins shows that the intelligent mammal has a seventh sense, electroreceptivity, which potentially plays a vital role in the marine animal’s survival.

Dolphins’ sensitivity to electric fields is due to vibrissal crypts which are small pits rich in nerve endings on their face, and they can detect electric direct current fields as weak as 2.4 microvolts per centimeter.

The two female dolphins – Dolly and Donna – tested field strength starting at 500 µV cm−1, which they both detected with a success rate of 96%, then gradually decreased. Dolly’s electrosensitivity reached 5.5 µV cm⁻¹ and Donna’s, 2.4 µV cm⁻¹. By comparison, the platypus – the first mammal known to have electroreceptivity – can detect fields of 25–50 µV cm⁻¹. Electroreception could extend to the capacity to orient oneself relative to the Earth’s magnetic field through electromagnetic induction in seawater.