Scientists in France are just starting to notice giant hammerhead flatworms around the country and French overseas territories. These invasive species were spotted in France since 1999.

This is the first time that scientists have looked into since reports of the worms.

Flatworm Invasion

Evidence of invasive flatworms in France goes back to almost two decades. The hammerhead flatworms are predatory worms that are usually found in Asia. When first notified about the flatworms in France, lead author of the study Jean-Lou Justine believed that this may have been a hoax. Justine is a professor at the National Museum of Natural History in Paris.

In a new study published in the journal PeerJ, an international team led by Justine found that several species of flatworms have been found in France. In a previous study, Justine had dismissed the invasive species as pests but he has since changed his conclusions.

To find evidence of the flatworms, researchers put out a call for photos of the worms. After receiving different pictures of various leeches, caterpillars, and slugs, they had to go through all the submissions. Researchers were able to find 111 observations of flatworms from 1999 to 2017. They found evidence of five species in France and French overseas territories.

Flatworm Sightings

Justine told Tech Times that he was amazed that scientists hadn't looked into the worms despite the number of sightings in the last 20 years.

"That amazes me. The worms were here, people were seeing them on a regular basis in their gardens, but not a single scientists worked on them," Justine told Tech Times. "I have no explanation."

Justine and his team were able to analyze three different species that were preserved from sightings. A portion of the sightings occurred in the south of France. Researchers believe that the weather plays a large role in the sightings, the summers are wet and the winters may allow the worms to survive.

Speaking to Tech Times, when asked how the worms may have affected French biodiversity he says he's not sure.

"We do not know. Our paper reports the presence of these worms. We know that they are predators, and we know that alien predators often have adverse effect on the populations of native animals, and on biodiversity of native animals," said Justine to Tech Times. "But no precise ecological evaluation of the impact has been done yet. That is a completely different job."