Are hagfish fish? They don’t have fins, but does that make something a fish? In reality, there is no taxonomic division that defines a fish. There are several classes of chordates that most scientists consider fish. The hagfish, are one of the most primitive classes whether or not you’re part of the group that believes they should be grouped with other fishes or not.
Hagfish have no jaws. In fact, hagfish are in a very primitive division within the entire chordate classification scheme. While they have a skull, they have no vertebral column. Recent literature suggests that hagfish might rather be classified as non-vertebrates. While chordates, they are often put into the sub-phylum Craniata. Despite the classification, and where scientists place them, hagfish are remarkable aquatic animals. In total there are about 60 species in 5 genera.
Hagfish have slime glands along their body-length which allow them to produce a slimy solution that aids in deterring predators. Sometimes hagfish have been called slime eels because of this (even though they are not related to the true eels). Hagfish are able to get themselves out of the slime they produce by tying themselves in a knot and squeezing away the slime.