World's Heaviest Earthworm Found, Then Killed

Dave, a 16-inch-long earthworm discovered recently in England, will become part of the collection at the Natural History Museum in London.

The Largest Earthworm Discovered in U.K. The invertebrate is also the heaviest of its kind ever found.

What Paul Rees recently discovered among his vegetables in England's Cheshire County is anything but garden variety: a gigantic earthworm.

Rees's stepson, George, named the behemoth Dave. He's the longest earthworm recorded in the United Kingdom—almost 16 inches—but it's his mass that has really impressed scientists. Dave weighs nearly an ounce, almost twice as heavy as any other wild earthworm ever seen. That's about the size of a small chocolate bar.

Before Dave, the largest earthworm (Lumbricus terrestris) was a Scottish specimen found in 2015 that weighed about half an ounce. (Read about the biggest insect that ever lived.)

In London, the Natural History Museum's Emma Sherlock said she was astonished by the find.

Dave the worm next to British currency. Earthworms can live up to six years in captivity.

“I was bowled over by the size of the worm when I opened the plastic box they sent it in,” Sherlock said in the press release. (The museum told National Geographic that Sherlock was not available for an interview.)

“I look forward to seeing if anyone can find an even bigger example by taking part in the Earthworm Watch survey this autumn," says Sherlock, who also chairs the Earthworm Society of Britain.

To the chagrin of many of his social media fans, Dave was killed for scientific reasons and will now be on display as part of the museum's collection.

Twitter users expressed their anger at the worm's fate at #davetheworm and even created a Twitter account for the dead invertebrate, @PoorDaveTheWorm.



Earthworms Make Happy Soil

This earthworm species is common throughout Europe, where they usually reach lengths of between eight to 10 inches. Because earthworms have many predators, the invertebrates normally do not survive long enough in the wild to reach Dave's proportions. Their life span is unknown, but the worms have reached six years old in captivity.

Dave also plays an equally huge role in his ecosystem by keeping soils healthy. The animals boost the soil's carbon storage by mixing in decomposing plant material, which also helps improve soil fertility. (Also see "Mysterious Mounds in South America Are Likely Worm Poop.")

For instance, earthworm burrows increase the amount of air and water in soil, making the land aerated and productive.

“With worms this size, Paul [Rees] must have an incredibly fertile and well-drained vegetable plot with decaying matter quickly recycled back into the soil,” Sherlock said.

Follow Mary Bates on Twitter.

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