These Worms Hitchhike in the Belly of Slugs To Get Around

New study shows that worm their way into slug guts and feces to travel long distances

Aleksander Rubtsov/Blend Images/Corbis

How do you get from point A to point B if you’re only a millimeter long? For supersmall roundworms, the answer is simple: just hitch a ride inside the nearest slug. New research has revealed that hitchhiking is the secret to mobility for hungry nematodes — that is, if you call worming your way into another creature’s guts and feces hitchhiking.

Roundworms are a surprisingly popular area of research. Since C. elegans nematodes are one of the simplest organisms with a nervous system of their own, they’re prized by scientists who use them to study neural development and conditions like Parkinson’s disease.

But despite their valuable contributions to science, researchers have never really understood how roundworms — which are super small, dry out easily and prefer ever-changing microhabitats — actually get around in the wild. That changed when a group of scientists collected over 600 slugs and about 400 other creatures ranging from flies to beetles. When they dissected the animals, they found millions of living nematodes in slug intestines.

To test their hypothesis that nematodes burrow into slug guts in order to move long distances, the team exposed 79 slugs to nearly 1,185,000 roundworms that had been tagged with flourescent material. They learned that roundworms not only made their way into slug guts, but that they survived the entire slug digestive system, making their way to new territory alive and well.

There’s still more to learn about how nematodes hang out in slug intestines, the research team says in a release — do they feast on bacteria inside slug guts? Do they somehow depend on snail trails for nutrition? But one thing is sure: for tiny worms, travel is a messy business indeed.

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