The sea lamprey has a large oral sucking disk filled with sharp, horn-shaped teeth arranged in many concentric circular rows around a rasp-like tongue. They have over 100 teeth in total, which they use to attach to other fish and rasp through their flesh to feed on blood and body fluids

. Specifically, the dentition includes multiple rows of various types of teeth: a bicuspid tooth on the supraoral lamina, 6-10 unicuspid teeth on the infraoral lamina, several rows of exolaterals and posterials, and a strongly W-shaped transverse lingual lamina with 12-14 cusps

. The teeth are made of keratin and have a hollow core to allow for replacement teeth to grow underneath

. In summary, sea lampreys have well over 100 teeth arranged in multiple circular rows on their oral disk, specialized for their parasitic feeding lifestyle