Britannica Sources used in this answer

Which animals belong to the jawless fish group called cyclostomes?

Created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

Illustration showing examples of vertebrates: a turtle for reptiles, a songbird for birds, a bluegill fish, a salamander for amphibians, and two mammals-a whale and a groundhog. — Vertebrate The major groups of vertebrates include fishes, amphibians, reptiles, birds, and mammals.

The term "cyclostome" refers to a group of living, jawless vertebrates belonging to the superclass Agnatha.12

The group consists of two primary classes of living fishes:34

Lampreys: Members of the order Petromyzontiformes, these fish are known for their round, suctorial mouths and parasitic feeding habits.34
Hagfishes: Members of the order Myxiniformes, these are exclusively marine animals that typically feed on invertebrates and dead fish.34

It is important to note that while the name "Cyclostomata" is also used in the classification of certain bryozoans (moss animals), those organisms are sedentary aquatic invertebrates and are entirely distinct from the jawless vertebrate fish group described here.5