Every few months a photo goes around online of a fisherman holding up an eel that looks impossibly big, sometimes with a caption claiming it’s the biggest ever caught. Most of those are real fish, usually European congers, but the claims attached to them are often exaggerated or impossible to check. In this guide I’ve sorted the eel size records into what’s properly verified, what’s reported but not confirmed, and what’s simply the maximum size a species is known to reach. I’ve also included a few “eels” that aren’t true eels, because that’s where some of the biggest numbers come from.

The record: a 133 lb conger

The heaviest eel ever landed on rod and line is a European conger from a wreck off Devon.

In 1995, angler Vic Evans landed a European conger (Conger conger) weighing 133 lb 4 oz, about 60.4 kg, while fishing a wreck off Berry Head near Brixham on the south Devon coast of England. It’s recognised as the British boat-caught record for the species and is widely cited as the largest conger ever taken on rod and line, an all-tackle world record under International Game Fish Association (IGFA) rules. Congers of that size are as thick as a man’s thigh and can be more than 2 m long.

Wrecks are where the biggest congers live. A sunken ship gives them dark, sheltered holes, and the fish that gather around a wreck give them plenty to eat. British and Irish wreck anglers have caught many congers of 80 to over 100 lb over the decades, and conger fishing on deep Channel wrecks has a dedicated following. You can read more about the species on our conger eel page.

Even bigger congers from commercial boats

Trawlers have reported heavier fish, but not to record standards.

Commercial fishermen in the North Atlantic have reported congers considerably heavier than the angling record, and maximum weights above 100 kg appear in some reference sources. Those fish weren’t weighed on certified scales with witnesses, so they don’t count as records, but there’s no biological reason to doubt that congers in the 70 to 100 kg range exist. The species grows for many years before it stops feeding, matures and swims to deep water to spawn and die, and the biggest individuals are females near the end of that long growth period.

That’s the source of many of the “giant eel” photos that appear online: a big conger hauled up in a trawl or caught on a long line. They’re impressive, but if you see a claim that a particular photo shows “the largest eel ever recorded”, treat it with caution unless it comes with a verified weight.

The biggest moray eels

One moray wins on weight, another on length.

The giant moray (Gymnothorax javanicus) of the Indo-Pacific is the heaviest moray, reaching about 3 m and 30 kg. It’s a thick, heavy-bodied fish and one of the top predators on many reefs, and it’s the moray that famously hunts alongside groupers in the Red Sea. On length, though, it’s beaten by the slender giant moray (Strophidon sathete), a thin, whip-like species of muddy bays and estuaries in the Indo-Pacific that can reach around 4 m, making it the longest eel species known.

In the Atlantic, the biggest moray is the green moray (Gymnothorax funebris), which reaches about 2.5 m. Green morays are common on the reefs in several of my dive guides, including Molasses Reef in Key Largo and the Santa Rosa Wall in Cozumel, and the Key West guide lists morays on the Cayman Salvage Master wreck. Big morays tend to live in big holes, which is why wrecks often produce the largest ones a diver will see. Our page on how big moray eels get goes through the moray species in detail.

The biggest freshwater eels

The largest river eels come from the Pacific and Indian Oceans.

The giant mottled eel (Anguilla marmorata) is the most widespread freshwater eel in the world, ranging from East Africa to the Pacific islands, and it can grow to about 2 m and 20 kg. In some Pacific and Southeast Asian communities big mottled eels live in village streams and are treated as sacred. More in our giant mottled eel profile.

The New Zealand longfin eel (Anguilla dieffenbachii) is the other heavyweight. Large females can approach 2 m and well over 20 kg, and they are among the longest-lived eels known, with some estimated at around a century old. Because longfins grow slowly and breed only once at the end of their lives, the biggest females are especially vulnerable to fishing.

By comparison, the American eel and European eel are modest. Big females of both species usually top out at around a metre or a little more and a few kilograms. The IGFA all-tackle record for the American eel is a little over 9 lb, from New Jersey in the 1990s, and the British record for the European eel has stood since 1978 at just over 11 lb.

Big “eels” that aren’t eels

Several large animals with eel in their name belong to other groups.

The electric eel is the largest animal commonly called an eel. It can reach around 2.5 m and 20 kg, and the species described in 2019, Electrophorus voltai, produced discharges measured at 860 volts. But it’s a South American knifefish, not a true eel. The wolf eel of the North Pacific grows to over 2 m, and it’s a wolffish. The rice field eel and other swamp eels are in their own order. Lampreys, which some people call lamprey eels, are jawless fish, and the largest, the sea lamprey, reaches about a metre. None of these count toward true eel records, though they often show up in “biggest eel” lists.

The six-foot larva and the sea serpent

A giant larva once made scientists wonder about enormous unknown eels.

Eels start life as leptocephali, flat transparent larvae that are usually a few centimetres long and later shrink when they turn into juvenile eels. In 1930 the Danish research ship Dana netted a leptocephalus off southern Africa that was about 1.8 m long. If eels grew in proportion to their larvae, the adult would have been a monster, and the find was seized on as possible evidence for sea serpents. Later work showed the giant larva most likely belonged to a notacanth, a deep-sea fish related to eels whose larvae grow very large and don’t scale up the same way. It’s a nice reminder of how little we knew about eel development, and why the stories collected on our sea monsters page lasted so long.

How eel records are verified

A real record needs a certified scale, witnesses and a positive ID.

Angling records are kept by the IGFA for the world and by national bodies such as the British Record (Rod Caught) Fish Committee. To count, a fish must be weighed on certified scales, the species must be confirmed, usually from photographs or the fish itself, and the catch must follow the rules on tackle. That’s why many genuinely huge eels never appear in record books: commercial catches, eels found dead and fish released without weighing don’t qualify.

My own view is that the eel records worth celebrating today are the ones released alive. Big female congers, longfins and freshwater eels are the breeders that keep populations going, and several freshwater eel species are already listed as Endangered or Critically Endangered. If you hook a giant, a quick photo and a careful release does more for the next record than a trophy on the wall. For how long these big eels live, see how long eels live.

Why the biggest eels are almost always females

In most eels, the giants are old females.

In freshwater eels, sex is largely decided by conditions during the growth years, and the two sexes follow different strategies. Males mature at a smaller size and leave for the ocean sooner. Females keep growing for years longer, because the number of eggs a female can carry rises steeply with body size, and she needs large fat reserves to fuel an ocean crossing without eating. The result is that nearly every record-sized freshwater eel is a female near the end of her life.

Congers show the same pattern. Female European congers grow much larger than males, which rarely exceed a metre or so, and the record-breaking congers taken from wrecks are females. That’s one more reason to release big eels where the law and common sense allow: a single large female can carry millions of eggs, and removing the biggest breeders hits a population harder than taking smaller fish.