Hagfish Slime Could Be Eco-Friendly Fabric

By Rachel Kaufman

Many people are disgusted by the hagfish. These squirmy, eel-looking creatures are known primarily for two repellent traits: eating dying animals from the inside out, and oozing four cups of slime in a fraction of a second.

But Douglas Fudge, an integrative biologist at Canada’s University of Guelph, in Ontario, has given us a reason to embrace the goo: It may one day be used to produce a strong, eco-friendly fabric. The recent study by Fudge and colleagues, published April 15 in the Journal of Experimental Biologyhas revealed that different hagfish species have very different methods for producing their defensive goo.

The Pacific hagfish (Eptatretus stoutii), seen in California. Photograph by Norbert Wu, Science Faction/Corbis

Emitted when the fish is stressed or trying to avoid predators, hagfish slime is made up of two parts: mucus and tiny fibers, each of which is about 6 inches (15 centimeters) long but only a micron wide. That’s much thinner than a human hair or blood cell.

The fibers give the slime its ability to clog the gills of any predator that dares to eat it, said Fudge, who has been studying the icky critters since 1997. (Related video: “Attacking Shark Gagged by Slime.”)

“It’s hard to describe in words,” he says. “People think they know what it’s going to be like, but they’re always shocked when they feel it.”

Although the slime itself doesn’t smell, “if you catch a hagfish on a boat and bring it up to the surface, it’s usually really stressed out . . . They tend to add things to the slime,” Fudge says. In other words, they defecate or vomit into their slime.

“It has the potential of being really disgusting, because they tend to feed on things that are already rotten to begin with.”

Unraveling Hagfish 

For his recent study, Fudge and colleagues studied the Atlantic and Pacific hagfish—two of the 77 known species.

In both Atlantic and Pacific hagfish, the slime strands are made inside special cells in the fish’s body; the cells produce tiny, coiled-up skeins that look like balls of yarn. When the skeins are spewed out of the Atlantic hagfish’s body with the slime—about 25,000 of them in one “sliming event”—the slime and the hagfish’s thrashing cause them to unravel. (See “Slime Has Memory but No Brain.”)

But in Pacific hagfish, the skeins come open in a different way. Fudge’s team found that in Pacific hagfish, the skeins are initially glued together with a protein-based adhesive that dissolves in seawater. The glue comes off, the threads unravel, and a hungry predator suddenly has a face full of mucus instead of a tasty meal.

How hagfish make these adhesives or produce a 6-inch-long (15 centimeter) thread so tightly coiled that it fits inside a single cell are still unanswered questions.

Sartorial Slime

Meanwhile, these slimy threads could have a practical use for humans. Hagfish slime threads are almost as strong and light as spider silk, which researchers have been trying to adapt for use in clothing for years. (Related: “Twisting Everyday Fibers Could Make ‘Smart Clothes’ a Reality.”)

“Spider silk is made within silk glands in this mysterious process,” Fudge said. “In hagfish slime, there’s a lot more self-assembly involved.”

Also, the genes that make a hagfish thread-producing cell are smaller than spider silk genes, so it should, in theory, be possible to implant those genes into a bacterium and produce reams and reams of hagfish slime silk, for use anywhere we’d currently use nylon—think stockings or workout pants, for example.

And since nylon is ultimately derived from petroleum, a hagfish-slime substitute could actually be good for the planet.

Hagfish Clothing Still Years Off

Fudge’s lab has successfully harvested small amounts of hagfish thread and spun it like silk, and earlier this year the team published a paper describing stronger fibers made from a related protein.

But hagfish-slime stockings and jackets are probably still years off. And Fudge admits that the fabric will need a marketing makeover. That said, there’s a historical precedent: “In the 1980s, eelskin wallets were all the rage,” he said. (See “As Fashion Week Ends, Pondering the Origins of Clothes.”)

“Everybody had an eelskin wallet, and it turns out that was actually hagfish leather. Some clever person realized that nobody’s going to buy anything called genuine hagfish skin.”

Follow Rachel Kaufman on Twitter.

  • Markus

    Mythbustrers did a special on the eel skin wallettes. someone claimed that they were made from electric eels and that property caused the wallets to erase all the data on credit cards and such. it was proved false soon because it was hagfish skin. not an electric eel

  • Teran

    I think it is good researching other organisms, however I do not think it is ok for humans to destroy other organisms for our benefit. I personally do not buy anything that has been made by animals (wallets, shoes fur coats). I do support finding alternate ways in producing things that are environmentally safe but this sounds like the Hagfish is going to get the short end of the stick and become over hunted.

  • Jacob

    In this situation, this fiber would be both friendly to the environment and to animals. If they were to continue genetically engineering bacteria to produce the reams, very few hagfish would be hurt in the process. In fact, using actual hagfish would be less practical or efficient, because the mucus (and potential vomit and excrement) would have to be washed out of the fibers and then disposed of. Now the question is, other than the fiber’s strength, what are its potential uses? What is it like? For clothing, is it smooth like silk? Does it breathe like cotton? Absorb moisture and insulate like wool? It is light and versatile like polyester? As far as other fabric uses, does it repel water like canvas or have bullet proofing potential like kevlar that spider silk is claimed to have? It’s great to learn that people are looking all sorts of new places for solutions to sustainability issues. Now I’m more interested in knowing how they plan to use what they found to make the world more sustainable.

  • Lisa Clark

    The hagfish secretes the slime when it is stressed or scared. What are they doing to encourage the hagfish to secrete the slime?

  • amanda


  • Jason

    The hagfish doesn’t really need a whole lot to make it secrete the mucus. Just picking it up will make the animal trigger the defense mechanism. No animal is harmed. Well, at least wouldn’t need to be. I’m wondering if it has other properties than clothing. Fuel source, etc. Lubrication. Well, it is kind of sticky. Hagfish Mucus Glue!

  • WhiteGhost

    Omg…this slime is even edible…
    I think someone can make some good money by selling bottles of that slime. I love slimy stuff, and yeah sure i saw that barrel-o-slime selling on ebay, in fact it’s some glue with borax…eww, poisonous! I don’t get how would somebody sell such stuff. Apparantly, hagfish slime can be such good replacement for that. I always wanted a bottle, no, a whole container of it!
    Where the slime lives!

  • Dick


  • Brendan B.

    To get the hagfish to produce the slime does NOT harm them at all. In Korea, where the slime is used in food dishes similar to the use of egg whites, they just bang on the outside of the container with a stick. I would take a good startle everyday in exchange for a predator free environment and good food.

  • bigboy72


About the Blog

Researchers, conservationists, and others share stories, insights and ideas about Our Changing Planet, Wildlife & Wild Spaces, and The Human Journey. More than 50,000 comments have been added to 10,000 posts. Explore the list alongside to dive deeper into some of the most popular categories of the National Geographic Society’s conversation platform Voices.

Opinions are those of the blogger and/or the blogger’s organization, and not necessarily those of the National Geographic Society. Posters of blogs and comments are required to observe National Geographic’s community rules and other terms of service.

Voices director: David Braun (dbraun@ngs.org)

Social Media