The Atlantic hagfish is a very unusual fish species: Hagfishes do not have bones or jaws. They can tie their long, thin body into a knot, and do so in order to eat and to clean themselves. And, they make slime as a means of protection.
Hagfishes have hardened cartilage instead of bones. Lacking jaws, these scavengers use their rasping teeth to attach to and feed on their prey. Their prey is mostly dead fish and marine mammals (although they are known to feed on small invertebrates). They are also able to take a "bite" of food by tying their long body into a knot and pulling their head backwards through the knot in order to pull their mouth—and a mouthful—off the carcass.
The hagfish often rasps its way into the body of a dead animal in order to feed there in safety; while outside the body of its prey, the hagfish is at risk of becoming dinner for other fish. And, when not feeding, it buries its body in the mud.
The hagfish has a unique way of defending itself from attack: it produces a slime using sea water. If a potential predator gets too close, the hagfish will release a chemical from a row of pores along its side. This chemical reacts instantly with the sea water and produces a stringy slime. One hagfish can fill a 4.5 litre (1 gal.) bucket with slime in seconds! The slime is thought to be inhaled by the predator fish, which suffocates.
To protect itself from its own slime, the hagfish ties its body into a knot. It then slides the knot along the length of its body, thereby wiping off the slime.
Atlantic hagfish can grow to 79 cm (31 in.) long. Their body design is nearly identical to species of fossilized hagfish. This means that hagfishes, including the Atlantic hagfish, have changed very little in 320 million years!
Atlantic hagfish are red-brown or blackish-purple, fading to grey-white on their belly. They have three pairs of barbels around their mouth. Hagfishes have very poor eyesight, but an excellent sense of smell. They are active mainly at night.
Atlantic hagfish are found in water below 12 °C (54 °F), at depths of between 20 and 1100 m (66 to 3608 ft.). When not feeding, they bury themselves in the sediments of the ocean floor and lie either completely buried, or with only their head visible.
The Atlantic hagfish is widely distributed in the Arctic ocean, and southward along both coasts of the North Atlantic. They are found in the eastern Atlantic, southward to Morocco and into the Mediterranean Sea. They are also found in the western Atlantic from Greenland to Labrador, and southward to New York.