Scientific name: Electrophorus electricus
The adult electric eel is an elongated, snake-like animal that reaches 2.5 m in length and 20 kg in weight. Due to their serpentine shape, they lack caudal, pectoral, and dorsal fins; the anal fin is well-formed and extends almost the entire length of the body. The entire body is cylindrical, with a flattened head and a large mouth. This fish’s skin varies from gray to brown/black with a white/yellow patch under the chin and throat. The electric eel is not quite an eel; In fact, it is a type of knifefish.
The electric eel is native to the rivers and lakes of northern South America. They are terrestrial creatures that hide in the mud and rocks of rivers and swamps, usually in very shady areas. At first glance, there seems to be very little special about this fish, and yet, as the name suggests, the electric eel has some amazing adaptations.
The eel’s vital organs are all located in the front part of the animal and take up only about 20 percent of the fish’s internal volume, considerably less than other fish. It has three distinct groups of modified muscles that have long ceased to contract for movement.
The electric eel’ breathes air, getting about 80% of its oxygen from the air. Air-breathing allows fish to live in waters where there is very little dissolved oxygen.
The cells of the main electrical organ of the fish form 5,000 to 6,000 disks stacked like plates. The small electrical impulses generated by each of these plates are harnessed and channeled to create a stream of electrical energy that the fish uses in various ways. The electricity generated by the fish is very weak and is generated as a pulsed signal by the organ of Sachs.
Aside from navigation and foraging, the electric field can be maximized by other triggers, when the eel is in danger or anticipates the approach of a nutritious snack. In a burst of short, sharp discharges, the eel can generate 650 volts with a current of 1 ampere. This pulsed wave of electricity penetrates the water and is powerful enough to kill a human or even a horse from a distance of 6m.
Fish need a lot of energy to generate these high voltages, but they can do so intermittently for at least an hour to maintain the strength of each shock.
The ability to generate, store and use electricity is not unique to the electric eel. Many other fish shares this ability. The only species capable of generating tension even partially comparable to the electric eel are the African electric catfish and torpedo rays, of which there are 69 species.
There are many electric fish such as star watchers, elephant noses, many species of knife fish, and rays. In all but the electric eel, electric catfish, and torpedo ray, electricity is used to find food or navigate. Electricity generation is relatively rare in marine fish, but more common in freshwater species that live in murky waters.
The only known mammal with an electrical sense is the platypus. Like many other electric fish, the electric eel is nocturnal. It will hunt anything small enough at night to be sucked into its wide jaws.
The electric eel is also unusual for its reproductive behavior. In the dry season, a male eel uses its saliva to build a nest in which the female lays her eggs. Up to 17,000 young hatches from the eggs in one nest.
The powers of electric fish are hard to overlook and have been known since ancient times. The ancient Romans stood in a shallow bath with a torpedo and killed themselves to relieve gout symptoms.
Electric eels have always been high on the list of brave (or foolish) zoo collectors. Some unfortunate horses or mules were herded into a pool of water inhabited by several fish, where they took enough beatings to at least knock them out. The fish’s batteries would eventually run out, allowing collectors to come up with strong nets and boots.