Mar 3, 20234 min read

Electric Eels

Updated: Mar 3, 2023

Houston, TX

You know about Eels, right? How many types of eels do you know? Do you know there are about 19 different types of eels identified so far? From the Fresh Water Eels to Deep Sea Large Necked eels or One Jaw Gulpers, there are about 19 wide families, 111 genera, and over 800 species of Eels. In case you were thinking Electric Eel is one among them, you would be wrong. An Electric eel (Electrophorus Electricus) is not actually an eel at all. Eels are a type of bony fish with a long slender body and a ray-fin. They belong to the order of Anguilliformes. Although Electric Eels very much look like eels, with an elongated eel body shape, they’re actually knifefish and are mostly related to catfish and carp, rather than eels. Scientists have re-classified electric eels multiple times. For now, this is the only species in its genus.

The electric eel has a slender, serpentine body with no scales; it is usually a dark gray to brown with a yellow-orange underside. Like eels, it has no pelvic or dorsal fins, but it does have an elongated anal fin, which helps it move through the water, and a smaller caudal fin.

Eel Anatomy Image Source: Thames Catchment Community Eels Project

Electric eel has a flattened head, which acts as its positive end and its tail acts as its negative end. As its name suggests, the coolest thing about electric eels is that it makes electric charges and works pretty much like a fish that has transformed into a battery. Whenever an electric eel senses a prey, an impulse from its brain signals those cells to open ion channels. As the channels open up, sodium ions flow through and release electricity, the same way a battery works.

Electric Eels have three special organs that help create their electrical charge. Those three organs are called the Main organ, the Hunter’s organ, and the Sachs organ. These Electric Organs make up about 80 percent of the fish’s body.

Its remaining vital organs are tightly packed within the anterior part of its body. The 3 electric organs have 5000-6000 specialized cells called electrocytes or electroplaques. Electric Eels release up to 0.15 volts, 1 ampere and 860 watts for 2 milliseconds. The three electric organs take up so much space in an electric eel’s body and are vital to the electric eel’s survival. They can also adjust the intensity of the shock, and can even curl up to release a bigger shock and as salt water is a good conductor of electricity, the knifefish releases a lot of energy. Some people compare it to a car battery and it definitely releases more energy than a normal wall socket at your house. To be exact, an electric eel releases up to 500 volts, which tires them out, because they use ⅔ of the Hunter’s organ as well as the Main organ. The hunter’s organ and the sach’s organ produce weak electrical charges. Electric eels let out weak and strong discharges based on their needs. The weak ones are commonly used for navigation, as they have bad eyesight, and communication and the strong ones are for hunting prey and keeping predators at bay. Electric eels are also known for their jump out of the water, pressing their chin or their positive end to a partially submerged mammal to release a bigger shock.

Electric eels can grow big! They can grow up to 6-8 (2-2.5 meters) feet long, as long as a tall grown man. In captivity, males live up to 15 years and females can live up to 22 years. They can weigh up to nearly 45 lbs and are recorded to have a top speed of 65 mph (miles per hour).

Electric eels mostly live in Northern South America, in the Amazon River and are widely spread across Brazil, the Guianas, Suriname, Venezuela, Colombia, Ecuador and Peru. They eat fish, birds, and even small mammals, using their shocks to hunt them. They frequently come to the surface to breathe, because they live in an environment where the water is poorly oxygenated, so they’ve adapted to breathe from the surface. There are also 3 types of electric eels - the Electric eel, Vari’s electric eel, and Volta’s electric eel. There are also other kinds of electric fish, including 500 other species. There are 19 species of catfish and Egyptians used the electric catfish, capable of delivering a shock of up to 350 volts, to treat arthritis pain. The Egyptian name for these catfish translates to angry catfish. I think I’ll start calling the electric catfish, angry catfish!

The electric eel mother lays about 1,200 to 1,700 eggs during the dry season, which is from May to October. The males then build nests made of their saliva and they guard the nests until the eggs hatch later during the rainy season, which is from December to May. Experts aren’t sure how spawning happens, and that is what we most research on these eels. Some say that it occurs in large batches throughout the dry season, and others say that the female lays her eggs all at once. To mate, they use the weak electric charge they use for navigation.

Thinking of the Electric Eel power makes me feel mystical about them, from their incredible shocks to reproduction. Want to have more eel’s electric fun? Solve this missing letters quiz!

1. Which order do electric eels belong to?