Slime is splattered across the animal kingdom. Tubeworms produce mucus that glows. Hagfish can make buckets of slime in an instant. And then there are snails.
"Snail slime specifically is fascinating — a natural work of art," says Mariella Gabler, a Ph.D. student in physical chemistry at the Max Planck Institute of Colloids and Interfaces in Germany. "The complexity and functionality are mesmerizing."
For new discoveries, everyday mysteries, and the science behind the headlines, follow NPR’s Short Wave podcast.
To that end, Gabler and her colleagues wanted to know more about the composition of the slime of a particular kind of terrestrial species that's native to central Europe, called Cepaea nemoralis, or the brown-lipped snail.
In a paper published in the journal Science, the researchers reveal that these snails tune the relative proportions of certain proteins and ions to create five different types of mucus, each with their own function and distinctive properties.
Understanding how the snails make different types of slime could serve engineers well in the creation of new materials, says Gabler, "because now they have a system that can produce different materials based on the same principal components."
She points to numerous potential applications, including developing a slime that might help seal a wound or deliver a drug.
A tiny mucus factory
The brown-lipped snail is a many-hued wonder. "It can come in a lot of different colors and patterns," says Gabler. "The shell colors are nuances of yellow, white, brown or pink."
And it produces an array of mucuses whose structures serve different purposes.
First, there's a sticky, yet slippery lubricant mucus that the snails use for locomotion, allowing them to adhere to a surface while gliding along with minimal friction.
They produce two types of defensive mucus. "When it feels stressed or threatened, it can produce either a foam, for example, to wash out small pests or a sticky glue to immobilize them," says Gabler.
There's a protective mucus that the snails use to seal themselves inside their shells in the winter. And they make an adhesive mucus, which allows them to cling to everything from wood to glass to aluminum.
"The versatility makes it a perfect model system to understand how it can tune these different types of mucus according to its needs," Gabler explains.
Gabler and her colleagues collected the snails they needed on rainy days right outside their institute. They fed them cucumbers, salad, and lichen.
And then Gabler coaxed the snails to produce each of their five slimes. She collected the adhesive and protective mucuses using thin tweezers. And she gathered the lubricant mucus when the snails secreted it as they moved around a wet glass bowl.
For the defensive mucuses, Gabler had to trick the snails by tickling them "and then collecting the mucus with a spatula that has a tiny spoon on its end," she says.
Following the mucus trail
Armed with a little bit of each mucus, the researchers then analyzed the samples to determine their composition. They found that they all contain similar proteins but the concentrations of those proteins vary.
Plus, distinct amounts of calcium and other ions, along with differences in how the slimes are secreted — give rise to the five varieties of mucus.
"The more collagen and calcium were present," says Gabler, "the stiffer, more cohesive and sticky mucus became."
The protective mucus, for instance, contains tiny calcite crystals "that induce hardness and brittleness into the material at the same time, making it a perfect mechanical barrier during hibernation," she says.
"There are immense potential applications," says Kausik Mukhopadhyay, a materials scientist at the University of Central Florida who wasn't involved in the study. "It could be cancer research, drug delivery, cosmetics."
He says that the lubricant mucus could be tweaked for use with catheters to help them glide into place in the body with less friction. The adhesive mucus, he adds, might be developed into something to help close a wound.
In other words, there's much to learn from a slimy snail.
"Nature is always smarter than us," says Mukhopadhyay. "We are just maybe 0.1% to what nature has synthesized — that is where we are right now."
So at least for the moment, the snails still have a head start.
Copyright 2026 NPR
