Order Cyclostomata is a group of jawless fish commonly known as lampreys and hagfish. These fish are characterized by their eel-like bodies and circular suction mouth, which they use to feed on the blood of other fish. While Order Cyclostomata is the scientific name used to refer to these animals, there are other synonyms that can be used interchangeably. These include Agnatha, Hyperotreti, and Myxinoidea, among others. Regardless of the name used to refer to them, these fish play an important role in the ecosystem, as they contribute to the health and balance of aquatic environments.