THE JAWLESS HAGFISH

I recently watched a video on television about this animal, whose name is a, misnomer (it is not a fish). The video was about the fishing industry that catches hagfish for commercial purposes. The fact that there is even an industry that seeks out hagfish surprised me! 

The hagfish is a fish but a very primitive jawless one (Fig. 1). It is the only known living animal that has a skull but no vertebral column (although it does have rudimentary vertebrae). They have no internal skeleton, and what is present consists of only cartilage. They produce massive amounts of milky slime, which provide protection for the animal. They are up to 1.4 m length. They are gray fo pinkish in color (Wikipedia, 2026). They lack scales, paired fins, and dorsal fins. They can “tie” their own bodies into knots in order to rake off excess slime. 

Overall, they resemble a fat eel (15 to 16 cm long = about 6.5 inches)) with a rather complicated mouth area consisting of a pair of sensory barbels (used for smelling) next to the mouth, which has numerous well-hidden teeth located inside the mouth on a plate that protracts and retracts. In the central part of their mouth region is a rounded nostril (hagfish have a good sense of smell). The length of the main body of the animal has numerous small pores along its sides. There tails are paddle-like.

They are deep-sea bottom scavengers and eat carrion (e.g., dead whales—note: the hagfish enter the actual cavities of dead whales that settle out on the ocean floor. Hagfish are night dwellers. They prefer muddy bottoms as deep as 5600 feet (1700 m). They occur in dense congregations, with up to 15,000 individuals. Females outnumber males. They do not migrate more than about 60 miles.  

Their geologic range is Carboniferous Period to Recent (almost unchanged in 340 million years.)

                                                                      

They have been referred to as belonging to the “Agnatha group” of fishes (note: A = without; gnathos = jaw). They lack true bony jaws and teeth.  They have a skull but no vertebrae (note: they are the only known living animals that have a skull but no vertebral column (although they do have rudimentary vertebrae). They use their raspy tongue to eat worms and carrion. They have a pointed snout and barbels around their mouth.

They are indeed eel-like but are not eels. They are jawless, marine fish that produce massive amounts of slime as a defense mechanism which can clog the gills of a predator. They use their rasping tongue to tear food. They have a biting mouth with a rasping tongue with two pairs of comb-shaped horny teeth. According to Wikipepia (2026), the poor vision of the hagfish is because their eyes lack a lens), which greatly reduces their vision. Interestingly, they are known to have one of the lowest blood pressures among the vertebrates. 

They are deep-sea carrion eaters that hunt for food at night (although the water is so deep and dark and hagfish are nearly blind, saying they are night dwellers is hardly justified). They prefer cold-water depths down to 1700 m (5600 feet). There are 67 living species of these animals which are referred to as myxines (or more commonly, as hagfish).

They live in temperate seas (i.e., prefer cold waters) in both hemispheres. They are absent in the Red Sea (they need salinity but the Red Sea might be too saline and/or too warm). 

They are eaten by humans! And, there is a thriving industry that uses nets to catch them for human consumption.

  Classification

Kingdom Animalia

Phylum Chordata

Class Myxini

Order Myxiniformes

Family Myxinidae

Genus Myxsine

Type Species M. glutinosa Linnaeus, 1758

There could be as many as seven genera. 

References

aquaticcomunity.com

Long, J.A. 1995. The rise of fishes. 500 million years of evolution. The Johns Hopkins University Press. Baltimore. 225 pp.

Wikipedia. 2026.