24 Interesting Eel Facts

Published October 4, 2024

Freshwater eels, such as the European eel and the American eel, are the only types of eels that are valued as food and are of major economic importance._[2]
There are over 800 species of true eels (Anguilliformes) that fit into 8 suborders, 19 families, and 111 genera._[2]
Electric eels are not true eels. They belong to the same group as catfish and carp._[12]
In Japan, freshwater eel (unagi) is considered a healthy and luxurious food._[13]
A six-foot conger eel attacked Jimmy Griffen and tore away half of his face while he was diving in Ireland. He had to undergo over two hours of surgery to repair the bite._[4]

Even though the New Zealand longfin eel is classified as endangered, over one hundred tons are commercially fished annually

New Zealand's juvenile longfin eels can climb 65-foot waterfalls and even man-made dams._[5]
The snowflake eel has an uncanny ability to lift its head above water and grab prey above the waterline with its second set of pharyngeal jaws._[11]
To help them slither around sharp coral and rocks, eels are covered in slimy mucous._[9]
Even though they are a top predator, eels have very poor eyesight. They do, however, have a keen sense of smell._[12]
Eels can swim forward and backward. Sharks are the only fish that can't swim backwards._[9]
Some eels can live for up to 85 years._[9]
A baby eel is called an elver._[12]
Moray eels have a second set of jaws hidden in their throats. Lined with teeth, the jaws can shoot out and grab struggling prey that is already caught between the first set of teeth._[10]

Moray eels have a double jaw

The heaviest eel in the world is the conger eel, coming in at 240 pounds and 10 feet long._[3]
Because electric eels have poor eyesight, they use electronic signals to navigate. They are capable of producing up to 650 volts, which is over five times the power of an American wall socket._[6]
Eels are a type of ray-finned fish belonging to the order Anguilliformes. Unlike most fish, eels do not have scales. They also don't have pelvic fins, which are common on most fish._[9]

The mysterious life cycle of eels

Eels undergo a life cycle called catadromy. This is when an animal is born in salt water, migrates to fresh water to grow, and then returns to the ocean to spawn._[1]
Eels are a good source of protein, omega-3 fatty acids, vitamins A, D, and E, and minerals like calcium, phosphorus, potassium, and magnesium._[8]
Aristotle was fascinated by eels. He proclaimed that they "came from the entrails of the earth" because he couldn't determine how they reproduce. To this day, scientists still don't know where in the Sargasso Sea they breed, and eels mating in the wild has never been observed._[7]
Since the 1980s, the European eel population has declined 95% and is on the critically endangered list. Their numbers have declined due to climate change, disease, dam building, and illegal trade._[7]
An eel's unique life cycle and habitat preferences provide insight into the health of an ecosystem, making them bioindicators for entire aquatic ecosystems._[12]
Eel larvae are called leptocephali. They are leaf-shaped and transparent until they change into their adult form._[12]