Vertebrate Zoology: A Tutorial - T. A. Dauda 2014

Multicellular organisms
Chordates
Subphylum Vertebrata, or Craniata — Class Cyclostomata — Subclass Myxini

All hagfish are marine animals. They inhabit temperate and subtropical waters of both the Northern and Southern Hemispheres, ranging from shallow coastal areas to depths exceeding 1,000 m. Their preferred habitat is Water of normal oceanic salinity—32–34‰. At a salinity of 29–31‰, hagfish cease feeding, and if salinity drops to 25‰ or lower, they perish. The subclass Myxini includes only a single order, Myxiniformes.

The body length of hagfish ranges from 50 to 60 cm. The dorsal fin is absent, and the eyes are rudimentary (lacking a lens). The Inner ear contains only a single semicircular canal.

A typical representative, the Atlantic hagfish (hagfish), is distributed along the coasts of Europe and North America. Most of the day, the Atlantic hagfish spends resting on the bottom, burrowed into the mud (at a preferred depth of 100–500 m). It emerges to hunt at night. Its prey consists of fish trapped in nets or weakened by disease. They devour their prey either individually or in groups.

Atlantic hagfish are not used for human consumption, although they are quite edible once cleared of their abundant slime. In the waters of New Zealand, the slender hagfish is found, while bdellostomatid hagfish are widespread throughout the Pacific Ocean.