Class Cephalaspidomorphi - Lampreys

Lamprey are by far some of the most primitive fish, along with hagfish.  They are called cyclostomes, meaning ’round mouths’ which refers to their lack of jaws.  Instead of jaws, lamprey have round sucker mouths.  Sea lampreys also lack bone.  Instead they have a skeleton of cartilage. 

Anadromous Fishes

Just like Salmon and Alewives, the Lamprey are fish that swim into freshwater to breed.  There are lampreys though, that never migrate to the ocean.  

Diversity

There are about 40 different species of lampreys in the following 9 genera:

Species listed under Cephalaspidomorphi