Electrophorus

Electrophorus is a genus of freshwater electric fishes in the family Gymnotidae, native to the river systems of northern South America. The genus currently comprises three extant species: Electrophorus electricus, Electrophorus voltai, and Electrophorus variae. Commonly known as electric eels, these fishes are elongated, cylindrical, scaleless, and can reach lengths of about 1 to 2 meters, with some individuals exceeding 2 meters. They are obligate air-breathers, capable of gulping air at the surface to supplement oxygen.

Anatomy and physiology: Electric eels possess three electric organs formed by modified muscle cells called electrocytes, occupying much of the body, especially along the trunk and tail. The organs generate electric discharges used both for sensing the environment and for stunning prey. They produce a low-voltage, continuous or pulsed electrical organ discharge used for navigation and communication in turbid water, and high-voltage bursts, typically up to about 600 volts, to subdue prey or deter predators. The electrical sense, known as electrolocation, allows them to detect distortions in the surrounding electric field.

Distribution and ecology: They inhabit slow-moving rivers, swamps, and floodplains in the Amazon and Orinoco basins, often in vegetated, oxygen-poor habitats. They are nocturnal ambush predators, feeding on fish, amphibians, and occasionally small mammals.

Taxonomic notes: The genus was long treated as monotypic, but a 2019 study split the diversity into three species: E. electricus, E. voltai, and E. variae, with distributions overlapping in some basins.

Human relevance: Electrophorus has contributed to studies of bioelectrogenesis and neurobiology; they are occasionally kept in large aquaria but require specialized care.