Lampreys: Cephalaspidomorphi

Lampreys (LAM-prees) are scaleless, eel-like fishes that have skeletons of cartilage (KAR-teh-lej) instead of bone. Lampreys do not have jaws, so they cannot close their mouths. The mouth and tongue are covered with many small, sharp teeth. Adult lampreys are 8–47 inches (20–120 centimeters) long. Lamprey larvae (LAR-vee) look like worms. Larvae are the early form of an animal that must go through metamorphosis (meh-tuh-MOR-pho-sus), or a change in form, before becoming an adult.