Agnatha is a class of jawless fish that includes species like lampreys and hagfish. These ancient creatures are characterized by their elongated bodies and lack of jaws, which distinguishes them from other fish. Instead of jaws, they have a round mouth filled with teeth-like structures, allowing them to feed on the blood and tissues of other animals. Agnatha are primarily found in marine and freshwater environments. They play important roles in their ecosystems, often acting as scavengers or parasites. Their unique evolutionary traits provide valuable insights into the development of vertebrates, making them significant in the study of evolutionary biology.