Hagfish Slime: The Ocean's Slimiest Survivor
Hagfish slime is one of the ocean's best defenses. When a shark bites a hagfish, the hagfish releases slime that swells in the water within a fraction of a second and clogs the attacker's gills. The shark usually lets go.
Quick Facts
- Group: Hagfish, eel-shaped jawless fish
- Nickname: Slime eels
- Defense: Slime that expands in seawater
- Escape move: Tying itself in an overhand knot
- Odd fact: Can absorb nutrients through its skin and gills
How Hagfish Slime Works
Hagfish have rows of slime glands along their bodies. When threatened, they release mucus and tiny thread bundles that unravel in seawater, creating a huge volume of slime. A 2011 study in Scientific Reports filmed sharks and other predators gagging and backing off after biting a hagfish.
Tying Itself in Knots
Slime is great for escaping, but a hagfish doesn't want to stay covered in it. It ties its body into an overhand knot and slides the knot from head to tail, scraping itself clean. It also uses knots to get leverage when tearing food.
A Skull but No Backbone
Hagfish are jawless fish. They are the only known living animals with a skull but no vertebral column.
Eating From the Inside
Hagfish are scavengers. They burrow into the carcasses of dead fish and whales on the sea floor, and they can even absorb dissolved nutrients through their skin and gills.
The Day Hagfish Slimed a Highway
In 2017, a truck crash on U.S. Highway 101 in Oregon spilled about 7,500 pounds of hagfish, and they released enough slime to cover the road.
Frequently Asked Questions
What is hagfish slime made of?
Mucus and long protein threads that unravel and expand when they hit seawater.
Why do hagfish tie themselves in knots?
To scrape off their own slime and to get leverage when tearing food.
What was the hagfish slime incident?
In 2017, a truck carrying about 7,500 pounds of hagfish crashed on Oregon's Highway 101 and slimed the road.
Related Stories
For Deep-Sea Fans
Read
Meet the hagfish's strange neighbors in Creatures of the Deep (4.8 stars). See it on Amazon
Amazon affiliate link: we may earn a small commission at no extra cost to you.
Wear & display
Find animal art, shirts and mugs in our Etsy shop.
Shop
Browse all our animals and accessories at the From Paw to Tail store.
Get one true animal story in your inbox each week. Sign up at the bottom of this page.
Sources
- Zintzen et al. (2011), Scientific Reports: Hagfish Predatory Behaviour and Slime Defence Mechanism: slime against predators
- Wikipedia: Hagfish: knots, skull without backbone, absorbing nutrients and the 2017 highway spill
- Aquarium of the Pacific: Pacific Hagfish: slime and knot tying
- Glover et al. (2011), Proceedings of the Royal Society B (PMC): Pacific hagfish absorbing nutrients across the skin and gills
More true animal stories: From Paw to Tail Blog