Question

Lampreys possess a large round sucker, lined with teeth, that surrounds the mouth and is used to feed on what?

Answer 1

blood

Like hagfish, lampreys also lack scales, but they have fins and a partial backbone. The most striking feature of lampreys is a large round sucker, lined with teeth, that surrounds the mouth  see Figure below  . Lampreys use their sucker to feed on the blood of other fish species.