page_title: Electroreception
section_title: Overview
hierarchical_section_title: Electroreception / Overview
caption_attribution_description: English: The “electric image” of the external environment is determined by the conductive properties of surrounding objects. The electric field emanates from the electric organ in the tail region (gray rectangle) and is sensed by the electroreceptive skin areas, using two electric “foveas” to actively search and inspect objects. Shown are the field distortions created by two different types of objects: a plant that conducts better than water, above (green) and a non-conducting stone, below (gray). Based on: Heiligenberg, Walter (1977) Principles of Electrolocation and Jamming Avoidance in Electric Fish: A Neuroethological Approach Springer-Verlag. ISBN 9780387083674.
context_page_description: Electroreception or electroception is the biological ability to perceive natural electrical stimuli. It has been observed almost exclusively in aquatic or amphibious animals since water is a much better conductor than air. The known exceptions are the monotremes
  , cockroaches, and bees. Electroreception is used in electrolocation and for electrocommunication.
context_section_description: Until recently, electroreception was known only in vertebrates. Recent research has shown that bees can detect the presence and pattern of a static charge on flowers. In vertebrates, electroreception is an ancestral trait, that is to say that it was present in the last common ancestor of all vertebrates. This form of ancestral electroreception is called ampullary electroreception, with the receptive organs themselves called Ampullae of Lorenzini. Not all vertebrates that possess electroreception have Ampullae of Lorenzini. Ampullae of Lorenzini exist in cartilaginous fishes (sharks, rays, chimaeras), lungfishes, bichirs, coelacanths, sturgeons, paddlefish, aquatic salamanders, and caecilians. Other vertebrates that have electroreception such as catfish, gymnotiformes, Mormyridiformes, monotremes, and at least one species of cetacean all have different secondarily derived forms of electroreception. Ampullary electroreception is passive, and is used predominantly in predation. Two groups of teleost fishes are weakly electric and engage in active electroreception: the Neotropical knifefishes (Gymnotiformes) and the African elephantfishes (Notopteroidei). A rare terrestrial exception is the Western long-beaked echidna which has about 2,000 electroreceptors on its bill, compared to 40,000 for its semi-aquatic monotreme relative, the duck-billed platypus.
caption: For the elephantfish (here Gnathonemus) the electric field emanates from an electric organ in the tail region (gray rectangle). It is sensed by the electroreceptive skin areas, using two electric pits (foveas) to actively search and inspect objects. Shown are the field distortions created by two different types of objects: a plant that conducts better than water, above (green) and a non-conducting stone, below (gray).[2][3]
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