Saltwater environments, such as oceans and seas, are not suitable for electric eels. Their bodies are specifically adapted for freshwater conditions, and they cannot osmoregulate or maintain proper water and electrolyte balance in saltwater. Furthermore, the high salt concentration in seawater would disrupt the electrical fields that they generate for sensing their surroundings and capturing prey.
Therefore, electric eels are strictly freshwater fish found in rivers, streams, and other freshwater bodies in South America.