BBC Earth
Image: kinskarije
Where to begin when describing the extraordinary biology of hagfish?
Like us they are vertebrates, but unlike us they do not actually have bony vertebrae in their backs: they are literally spineless. They have several hearts, and at least twice as much blood in their bodies as other fish. On top of that, they have only half a jaw, yet they can still tear through tough flesh.
What’s more, hagfish have skin so floppy that it should seriously compromise their swimming. They lack scales, they can absorb some of their food straight through their skin – bypassing their half-jawed mouths altogether – and they have an almost unrivalled ability to turn seawater into thick gloopy slime.
Put simply, hagfish are like nothing else in the animal kingdom. But it is possible that many of their unusual traits can be explained by one final feature. These fish can tie their bodies into tight knots. Read more on the BBC Earth website…
