Pacific Hagfish

The Pacific hagfish defends itself by exuding massive quantities of thick, sticky slime from glands running along its body. When attacked by a predator, like a shark, this slime instantly clogs the predator's gills, causing them to gag and retreat. A single hagfish can produce liters of this slime in a matter of minutes.

As a primitive deep-water scavenger, the Pacific hagfish feeds primarily on dead or dying marine life on the ocean floor. It uses a unique dental plate to burrow directly into the flesh of whale falls and deceased fish. They can absorb nutrients through their skin while consuming a carcass from the inside out.

To avoid suffocating in its own slime, the Pacific hagfish ties its body into a tight knot and slides the knot from head to tail. This physical action scrapes the sticky slime off its body. The knot-tying behavior is also occasionally used to gain leverage when tearing meat off a larger carcass.

The Pacific hagfish is a jawless, eel-like marine animal native to the North Pacific Ocean, but it is not considered a true bony fish. It belongs to the ancient class Myxini and lacks a true vertebral column. Because it has a skull but no spine, it occupies a unique and evolutionarily crucial branch of early vertebrate development.