Getting tied up in knots is something this fish take really seriously – the hagfish (Myxini) turns itself into a marine pretzel to twist its prey to pieces.
But wait, there’s more. The hagfish is also covered in slime. This icky substance gums up the gills of any predator that tries to make a meal out of it causing the attacker to spit it out unharmed. They are also known for being able to squeeze through the tiniest of spaces and even survive shark bites unscathed. This was recently reported by researchers of the Society of Integrative and Comparative Biology.
Hagfish aren’t a typical fish—they have cartilage instead of bones and a primitive skeletal rod (called a notochord) instead of a backbone. This aids the fish’s survival due to the fact that its skin is only loosely connected to the muscles and organs inside the body.
Source: www.sciencemag.org