Electric organ (biology)

Article By:

Bennett, Michael V. L. Department of Neuroscience, Albert Einstein College of Medicine, New York, New York.

Last reviewed:December 2019

DOI:https://doi.org/10.1036/1097-8542.216500

An effector organ found in six different groups of fishes; output is an electric pulse (Table 1; Fig. 1). Voltages large enough to aid in prey capture or predator deterrence are produced by various strongly electric fishes. These include the electric eel (Electrophorus electricus) from South America; the electric catfish (Malapterurus electricus) from Africa; the family of electric rays, Torpedinidae, which are widely distributed in the world's oceans; and possibly the stargazer genus, Astroscopus, of the western Atlantic. Weakly electric fishes emit a lower voltage, the energy source for an active electrosensory system that monitors electrical impedance in the environment. These weak signals also serve in intra- and interspecific communication. There are three groups of weakly electric fishes. First, the South American knifefishes, the Gymnotiformes, are a large and diverse group of several families that also include Electrophorus. Second, the electrically active African Mormyriformes are composed of the numerous species of the family Mormyridae and the single species Gymnarchus niloticus in the family Gymnarchidae. Finally, many species of skates and rays of the family Rajidae occur in marine waters worldwide.

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