Electroreception

Electroreception is the biological ability to detect electric fields in the environment. It is most pronounced in aquatic animals and some mammals, where it supports prey detection, navigation, and social interactions.

There are two main forms. Passive electroreception involves sensing external electric fields produced by other organisms or by changes in the environment. In cartilaginous fishes such as sharks, rays, and skates, this sense is mediated by electroreceptors called Ampullae of Lorenzini. These gel-filled canals extend into the skin and connect to sensory cells that respond to voltage gradients, helping the animal locate prey and orient in low-visibility waters.

Active electroreception, or electrolocation, occurs when an animal emits a weak electric field and detects distortions caused by nearby objects or organisms. This form is best known in weakly electric freshwater fishes, including gymnotiforms (such as electric eels) and mormyrids, which use the information to determine the position, size, and electrical properties of surrounding targets.

Electroreception is also present in the platypus, which uses electroreceptors in its bill to detect the bioelectric signals generated by prey during foraging. The sensory cells are specialized electroreceptors, often integrated with other mechanosensory systems in the skin. The sense is highly sensitive, capable of detecting microvolt-level fields in favorable conditions, and has evolved independently in several vertebrate lineages. Its ecological roles include prey detection, predator avoidance, spatial navigation, and, in some species, social communication.