Electric eel

Native Habitat

This species is widely distributed across northern South America. Its range spans across Brazil, the Guianas, Suriname, Venezuela, Colombia, Ecuador and Peru. Electric eels inhabit the quiet, slow-moving waters of ox-bow lakes, streams, pools and flooded forests of the Amazon and Orinoco Rivers, preferring side channels but also living further inland.

Both of the rivers these fish inhabit are subject to a natural fluctuation of water driven by precipitation patterns, which results in two distinct seasons: wet and dry. The two seasons bring about drastic changes in available habitat for electric eels.

During the rainy season, the rivers swell, re-connecting lakes and ponds as the forests flood. Juvenile electric eels disperse and expand into new territories. As water recedes in the dry season, large groups of fish become isolated in the pools and smaller streams that remain.

The water in these areas is poorly oxygenated, but electric eels are specially adapted to thrive in this environment. They are obligate air-breathers, which means they surface for air periodically. Their mouths are heavily vascularized with folds that increase the surface area, allowing them to breathe air, rather than trying to meet their respiration needs through gills in warm, anoxic waters.

Throughout the dry season, the electric eel is also at greater risk from predators, such as large mammals, that hunt from outside the shallow waters it inhabits. Because there is little space to retreat, the fish is often forced to defend itself.

Water efficiently conducts electricity, providing a wide surface area for the electric eel’s shock to be applied. This means that an electric pulse delivered through the water may not be as painful for a large predator as one delivered outside of the water. As such, an electric eel can instead jump out of the water, sliding its body up against a partially submerged predator to directly target its shock. The eel then delivers its electric pulses in increasing voltages.