How does a lamprey rasp through the tissues of its prey?

To feed on its prey, a lamprey first attaches itself to the side of the host fish by creating suction with its circular oral disk, which is lined with sharp, hooked teeth. Once securely attached, the lamprey uses a specialized, toothed, tonguelike structure located on the floor of its mouth to rasp a hole into the host's flesh.12

To facilitate the ingestion of blood and muscle tissue, the lamprey secretes saliva containing an anticoagulant from its mouth, which prevents the host's blood from clotting.12