lam·prey 
(lămprē)
(lămprē)n. pl. lam·preys
Any of various elongated freshwater or anadromous fishes of the family Petromyzontidae, having a jawless sucking mouth with rasping teeth and often attaching to and parasitizing other fish.
[Middle English lamprei, from Old French lampreie, from Medieval Latin lamprēda, perhaps of Gaulish origin.]
lampreysea lamprey
Petromyzon marinus