Hagfish eat worms and invertebrates, but they also enter both dying and dead fish and eat them from the inside out.

How do Agnatha feed?

Most of them feed on small particles suspended in sea water. The water is drawn into the mouth and pharynx by means of a cilia-induced current, and food particles are trapped and carried to the alimentary tract by strings or sheets of mucus.

How does the jawless fish eat?

Jawless fish: Lack jaws. Feed by suction with the help of a round muscular mouth and rows of teeth.