Eels are elongated, serpentine fish belonging to the order Anguilliformes. This group is defined by the lack of pelvic fins and the fusion of their dorsal, caudal, and anal fins into a continuous ribbon. Eels are widespread, inhabiting marine environments globally, from shallow coastal waters to the deep oceanic abyss, and some journey into freshwater systems. Their impressive size naturally leads to questions about which species holds the title for the largest.
The World Record Holder
The undisputed record holder for the largest eel by overall mass is the European Conger Eel (Conger conger). This species, belonging to the marine Congridae family, is considered the heaviest true eel. Its dominance is established through its immense bulk, which exceeds that of other contenders, even those that may be slightly longer. The European Conger Eel is widely distributed across the Eastern Atlantic Ocean, extending from Norway and Iceland down to Senegal, and is also prevalent throughout the Mediterranean and Black Seas.
Specific Size and Habitat of the Record Holder
The European Conger Eel’s reputation is built on its formidable maximum dimensions. While average adults measure around five feet, the largest specimens have been recorded reaching lengths of up to 10 feet (3 meters). The heaviest individuals are reported to weigh approximately 240 pounds (110 kilograms), though historical accounts suggest weights nearing 350 pounds (160 kilograms). This massive size is supported by a robust, muscular body, typically dark gray or blackish with a lighter white belly.
These large predators prefer deep, rough, and rocky environments along the continental shelf. They often inhabit “eel pits,” which are complex networks of rocky crevices, shipwrecks, and caves used for shelter during the day. The species is primarily nocturnal, emerging to hunt fish, cephalopods, and various crustaceans.
The European Conger Eel typically resides between 0 and 1,640 feet, though individuals have been observed at depths of over 11,800 feet during spawning migrations. Females grow significantly larger than males, reaching sexual maturity at about six and a half feet. Their substantial lifespan allows them the necessary time to attain their record-holding bulk, aided by a powerful set of conical teeth.
Other Contenders and Eel Lookalikes
The title of “biggest eel” is sometimes contested by other large species, particularly the Giant Moray (Gymnothorax javanicus) and the Slender Giant Moray (Strophidon sathete). The Giant Moray is the largest moray eel in body mass, often rivaling the Conger Eel in bulk, but its maximum weight is typically lower, reaching approximately 66 pounds at 10 feet long. The Slender Giant Moray is often cited as the longest eel in the world, with specimens recorded up to 13 feet, but its thinner body means it does not carry the immense weight necessary for the overall size record.
Confusion often arises with species that share the elongated body shape but are not true eels. The most prominent example is the Electric Eel (Electrophorus electricus), a massive freshwater fish from South America that can reach over eight feet. Despite its name, the Electric Eel is not classified in the order Anguilliformes; it is technically a knifefish belonging to the order Gymnotiformes. This distinction means the Electric Eel is more closely related to catfish and carp than to the European Conger Eel.