Electric eels generate their own electricity, a unique biological capability. Their ability to produce electrical discharges allows them to navigate their surroundings, locate food, and protect themselves from threats.
Generating Their Own Power
Electric eels produce electricity through specialized cells called electrocytes, which are modified muscle cells. These disc-like cells are arranged in long columns within three electric organs: the main organ, Hunter’s organ, and Sachs’ organ. These organs can make up a significant portion, about 80%, of the eel’s body length.
When generating a discharge, an electric eel’s brain sends a signal to its electrocytes. This triggers a rapid flow of ions, primarily sodium and potassium, across cell membranes. Each electrocyte generates a small voltage, similar to a tiny battery. By stacking thousands of these cells in series, like batteries in a flashlight, the eel amplifies these individual voltages to produce a much larger electrical output.
Why Electric Eels Shock
Electric eels use electrical discharges for various purposes. They employ high-voltage shocks primarily for hunting prey and defending against predators. When a potential meal or threat is detected, the eel releases powerful bursts of electricity, stunning or incapacitating fish and other small animals. This rapid paralysis allows the eel to quickly capture its prey or deter an aggressor.
In addition to powerful discharges, electric eels also produce low-voltage electrical pulses. These weaker signals are used for electrolocation, helping the eel navigate and sense its environment in murky waters. Their poor eyesight means they rely heavily on this electrical sense to detect objects, other animals, and potential food sources. This adaptation is crucial for their predatory lifestyle.
Measuring the Shock
The electrical discharge from an electric eel can be substantial, with some species capable of generating up to 860 volts. The common species, Electrophorus electricus, typically produces shocks of at least 600 volts. While the voltage is high, the current delivered is relatively low, typically around 1 ampere. This combination of high voltage and lower amperage means that while a shock is painful and can be temporarily incapacitating for a human, it is rarely fatal on its own.
The impact on humans is often described as a brief, numbing jolt, similar to a stun gun. The primary danger to humans comes not from the shock itself, but from secondary effects such as falling and drowning in water, or from multiple shocks leading to respiratory or heart failure, particularly for individuals with pre-existing heart conditions. For comparison, a standard household electrical outlet typically provides 120 or 240 volts, illustrating the significant power an electric eel can generate.
Beyond the Name
Despite their common name, electric eels are not true eels. True eels belong to the order Anguilliformes, while electric eels are classified within the order Gymnotiformes, making them a type of knifefish. They are more closely related to catfish and carp than to the eels found in oceans. The name “eel” likely comes from their elongated, snake-like body shape, which can reach lengths of up to 2.5 meters.
This physical resemblance led to their common misidentification. In 2019, the genus Electrophorus was divided into three distinct species: Electrophorus electricus, Electrophorus voltai, and Electrophorus varii.