Myxiniformes

The order Myxiniformes, commonly known as hagfishes, comprises about 70 species of marine vertebrates that are considered primitive jawless fish, belonging to the superclass Agnatha. These eel-like creatures are scaleless and have soft skin, with paired barbels around their mouths. They lack jaws and bones, possessing instead a cartilaginous skeleton. Hagfishes have poorly developed eyes, often covered by skin, and a single nostril. They respire using multiple pairs of gills, which may open separately or into a common duct depending on the family.12

Hagfishes inhabit cold seawater, typically at depths up to 1,300 meters (4,260 feet), living on soft bottoms and often burrowing, with only their heads exposed. They feed on marine invertebrates and dead or injured fish, sometimes entering nets to consume fish from the inside. To defend against predators, hagfishes secrete large amounts of slime from specialized glands along their bodies.123