Yes, that was a bit of a eureka feeling, says Sytske de Waart about the moment she sat on her knees in a greenhouse in Amersfoort and saw a small milky white, shiny worm. Her colleague had found the worm and called her over. De Waart looked, and looked again, counted four eyes, and realized: this is special.
The creature that De Waart, flatworm taxonomist and researcher at Naturalis, had under her microscope, was a land cordworm (Leptonemertes chalicophora). The animal is an exotic species: it originally comes from islands in the North Atlantic Ocean and was brought along via potted plants that were imported to the Netherlands.
De Waart and her colleague were the first in the Netherlands to find the animal here, as bycatch in another study commissioned by the Dutch Food and Consumer Product Safety Authority (NVWA). “We don’t yet know whether there are more, and whether they also live in gardens. But there is a good chance that we will encounter them more. Once an exotic species is there, it never goes away.”
The video below shows how a land cordworm moves:
De Waart and her colleague found the animals in the greenhouses of the Hortus in Amsterdam and DierenPark Amersfoort. She published about it in the scientific journal magazine Dutch Faunistic Communications. In fact, De Waart mainly conducts research into the land flatworm (not to be confused with the earthworm). The flatworm does resemble the land cordworm. They both live in the ground, are active at night and during the day they sit in damp places under stones, buckets or under pieces of wood (they are not big fans of daylight). “They’re always hidden somewhere.”
The biggest difference is that the land cordworm has four eyes, and a flatworm has two, or a whole row of eyes on the side. Moreover, the land cordworm is often smaller (1 centimeter) than the flatworm (1 to 3 centimeters) and has a kind of proboscis with which it quickly grabs its prey. “Wonderful to see.” They move along their own slime trail.
Beautiful creatures
“They are really beautiful creatures,” she continues. “I know I’m about the only one in that. Few people share that opinion. But if you look closely at the land cordworm, for example, you see these white spots through the skin, those are probably the eggs, and You see he has a reddish head, and then those four eyes.”
“We hope that people who see one will report their sighting with a clear photo via the Waarneming.nl site. But so far it has not yet been found in gardens.” Another land cordworm that already lives in gardens is the Argonemertes dendyi, which was found in her garden by a woman in Wijchen in 2019. People can now find these themselves, especially under stones, buckets and wood, in their own garden. That was the first land cordworm found in the Netherlands.
And so more and more exotic species enter our country. Because it is getting warmer here, it is becoming more comfortable and easier for them to survive. De Waart recently found leeches that had never been found anywhere else in our country. And provinces are struggling with the arrival of the American crayfish: also an exotic species that is eating our freshwater lakes dry.
It is not yet clear whether the land cordworm is harmful to our soil. “There is a land flatworm in New Zealand that is very bad for the earthworm fauna. If it came here, I would think: ooh, shit. But that is not yet the case with the land cordworm.”
“We don’t know what the land cordworm eats,” says De Waart. “Probably small soil animals such as snails. And they are themselves eaten by the land flatworm. It just depends on who is the largest and strongest at that moment.”
According to De Waart, it is important to monitor how the worm behaves and how often it occurs. “It’s not ideal, such an exotic species, but you can’t stop it. They hitch a ride with the pot plant trade, and are then so difficult to find. The only thing we can do is hope that they have natural enemies, to take their place in our biotope and participate in the food chain.”
2024-01-02 13:39:19
#Small #shiny #trunk #exotic #worm #time #Netherlands
