What do you think of this fact?
A predator bites down and a moment later its mouth is full of goo. Welcome to the world of hagfish. They can turn a spoonful of slime precursor into about a liter of slime in less than a tenth of a second.
Slime with built-in threads
Hagfish aren’t eels at all. They’re an ancient group of jawless sea creatures that has barely changed in around 300 million years. When one is attacked, glands along its body release thousands of tiny packets into the water. They swell up within milliseconds.
The secret is tiny threads. Each slime cell produces a single thread about 15 centimeters long, roughly 1000 times the length of the cell itself. In the water, the threads unravel and hold everything together. The result is about 100,000 times softer than gelatin and clogs attackers’ gills.
Supposedly, a single hagfish can even fill a 5-gallon bucket, just under 19 liters, with slime in a few minutes. Smithsonian Magazine, however, explicitly files that under “hagfish mythology,” and nobody seems to have actually measured it.
Knots instead of tissues
Which raises the question: how do you get rid of your own slime? Hagfish tie themselves in knots and slide the knot along their body so the goo doesn’t drip onto their face. The knot trick helps with eating too: a knot in the tail gives their bite extra power.
Their anatomy is just as strange. Hagfish have a skull made of cartilage but no real backbone. It’s not quite that simple, though: in 2011, researchers found small vertebra-like bits of cartilage in a Japanese species. So hagfish probably lost most of their vertebrae over the course of evolution.
Hagfish have no jaws, just two rows of horny tooth-like structures. And they can absorb nutrients directly through their skin.
A fish that ties itself in knots, slimes its enemies and eats through its skin: next to that, every movie monster looks pretty tame.