Pacific Hagfish

The Pacific hagfish is a jawless, eel-like fish that lives on or near the seafloor of the Pacific Ocean, from shallow water down into the deep sea. It has a body plan that has changed little since early in fish evolution, with no jaws, no paired fins, and a skull made of cartilage rather than a true backbone. When threatened or grabbed by a predator, it can release enormous quantities of thick slime from glands along its body, clogging the attacker's gills and often allowing the hagfish to escape.