PARIS — Scientists have discovered that an invasive species of flatworms have been quietly occupying French soil for the past two decades.
The Washington Post reports that they would have gone unnoticed if not for amateur naturalist Pierre Gros, who spotted the strange critters in his garden, and Jean-Lou Justine, a zoologist at France's Museum of Natural History who later identified them as hammerhead flatworms.
According to the journal PeerJ, hammerheads are a giant species of flatworms with shovel-like heads that are native to Asia. They can grow up to a meter long and appear to reproduce asexually.
Citizen sightings indicate that at least three hammerhead species have been in metropolitan France as early as 1999, with two others reported in overseas territories.
The invasive species feed on earthworms in the soil, which they immobilize by secreting small amounts of the paralytic poison tetrodotoxin — the same neurotoxin found in the potentially lethal Japanese delicacy fugu or puffer fish.
Since earthworms help aerate soil and keep it fertile, scientists worry that the presence of predatory flatworms may threaten biodiversity and drastically affect the ecosystem.
They believe the worms were likely transported to Europe via tropical plants, but remain baffled by how they went undetected for almost 20 years.
