Lamprey

Lampreys /ˈlæmpreɪz/ are a group of jawless fish comprising the order Petromyzontiformes /ˌpɛtroʊmɪˈzɒntɪfɔːrmiːz/. The adult lamprey is 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. Lamprey is sometimes seen for the plural form. There are about 38 known extant species of lampreys and around seven known extinct species. They are classified in three families: two small families in the Southern Hemisphere (Geotriidae, Mordaciidae) and one large family in the Northern Hemisphere; (Petromyzontidae).

Source: Wikipedia