Sometimes known as slime eels, hagfish are a form of marine life that is usually classified as classified as a type of fish. However, there is some feeling that the hagfish is actually a member of a sea dwelling species that does not readily fit into the usually accepted definition of fish. Part of the marine class myxini and with a scientific designation of hyperotreti, the hagfish is usually considered to be one of the less desirable forms of ocean life.
In appearance, the hagfish features an elongated body that is very much like that of an eel. The tail area is distinguished with small paddle-like fins that help the slime eel to steer through the water. Depending on the variety of hagfish, the creature may possess vestigial eyes or none at all. Generally, the hagfish has a single nostril and a mouth that is constructed around jaws that move in a horizontal manner. The jaws and mouth area include projections that resemble teeth, as well as protrusions around the mouth that help to move food into range for tearing. Like the presence and position of the eyes, the color of these marine craniates will vary depending on the type.
The hagfish generally feeds on the internal organs of dead fish. Often, the hagfish will enter the body of the dead fish through the gills, mouth, or anus, rather than ripping through the skin. Fishermen tend to find the hagfish as annoying as it is aesthetically unpleasant, since it can begin to eat the catch before the fish are pulled into the boat.
One of the main characteristics that generate a sense of disgust is the excretion of a thick level of slime when the creature feels threatened in any way. The slick coating helps the hagfish to escape from danger, as the slime makes it almost impossible to maintain a strong grip on the creature. Once free from the predator, the hagfish can manipulate its body into a knot and then slowly work the knot for the entire length of the body. As the knot descends, the layer of slime is skimmed off the surface of the skin, leaving the residue floating in the open water.