the world > animals > fish > superclass Agnatha > [noun] > suborder Petromyzontoidei or genus Petromyzon > member of (lamprey) > fresh-water (6)
The river lamprey (Petromyzon fluviatilis).
A freshwater lamprey, esp. a larval or young one; spec. the lampern, Lampetra fluviatilis.
a lamprey occurring in rivers; spec. (in Europe) the lampern, Lampetra fluviatilis, and (in western North America) L. ayresii.