Giant predatory worms invade France, shock biologists

Pic courtesy: PeerJ (Photo by Pierre Gros)

New Delhi: An amateur naturalist named Pierre Gros from Paris, took a scientist by surprise, when he sent him photos of a Hammerhead flatworm, with a head like a shovel, which grows to a foot or more in length. They are said to be native to Asia and do not belong in European vegetable gardens.

Justine, a professor at the National Museum of Natural History in Paris and a specialist of the systematics of monogeneans and certain parasitic nematodes, was taken by surprise at the photos sent to him by the gardener. Gros and Justine are now the co-authors of a new report published in the journal PeerJ. 

"The species are cryptic and soil-dwelling so can be easily overlooked, which often explains their inadvertent shipment around the world," entomologist Archie Murchie of Britain's Agri-Food and Biosciences Institute, not involved with the study, was quoted as saying by Science Alert. He also warned that worms like these will continue to spread. 

Smaller worms, which eat escargot snails, were known to have made their way to France, but Hammerhead flatworms too had invaded the country was a revelation for them.

Justine and his colleagues urged people through local news stations and online requests to send them photos of large worms with broadheads. They received numerous pictures of leeches, caterpillars other invertebrates tubular and sticky, the report said. It was found that people had made 111 observations of large flatworms between 1999 and 2017. Many sightings were in the south of France.

To quote the report published in PeerJ - "The present findings strongly suggest that the species present in Metropolitan France and overseas territories should be considered invasive alien species... As scientists, we were amazed that these long and brightly coloured worms could escape the attention of scientists and authorities in a European developed country for such a long time."

Hammerhead flatworms are said to hunt through the soil and their bodies produce small amounts of a substance called tetrodotoxin, which immobilises prey.