Electric fish

Electric fish produce electrical discharges or detect electrical fields using specialized biological systems. These abilities support communication, navigation, prey capture, and defense.

Electric organ: A specialized tissue that generates electrical discharges from coordinated cells called electrocytes. Its electrocytes create the discharges characteristic of strongly electric fish.
Action potential: A rapid, temporary change in a cell's membrane voltage that propagates along excitable tissue. Nerve signals trigger electric-organ activity and carry sensory information.
Electric eel: A South American knifefish that produces powerful discharges for hunting and defense. It is the best-known example of an electric fish using high-voltage shocks.
Convergent evolution: The independent evolution of similar traits in different lineages, often under similar selective pressures. Electric organs evolved independently multiple times among fishes.
Electrogenic fish: A fish that generates an electric field through a specialized organ or tissue. This narrower term excludes fish that only detect electrical fields.
Electrocyte: A modified cell that produces voltage through ion movement across its membrane. Stacks of these cells combine their small voltages into an electric-organ discharge.
Ion channel: A membrane protein that allows selected ions to cross a cell membrane. Ion channels generate the voltage changes used by electrocytes and sensory cells.
Weakly electric fish: An electric fish that emits low-voltage discharges mainly for sensing and communication. Its weak signal supports active electrolocation and social signaling.
Mormyridae: An African family of freshwater fishes that includes many weakly electric species. Its members evolved electrolocation independently from South American knifefishes.
Electrosensory fish: A fish that detects electrical fields, whether or not it produces them. It distinguishes sensory ability from the ability to generate electrical signals.

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