Lampreys (sometimes also called lamprey eels) are any jawless fish of the order Petromyzontiformes. The adult lamprey may be characterized by a toothed, funnel-like sucking mouth. The common name "lamprey" is probably derived from Latin lampetra, which may mean "stone licker" (lambere "to lick" + petra "stone"), though the etymology is uncertain.Currently there are about 38 known extant species of lampreys.