\Lam"prey\, n.; pl. {Lampreys}. [OE. lampreie, F.
lamproie, LL. lampreda, lampetra, from L. lambere to lick +
petra rock, stone. The lampreys are so called because they
attach themselves with their circular mouths to rocks and
stones, whence they are also called {rocksuckers}. See {Lap}
to drink, {Petrify}.] (Zo["o]l.)
An eel-like marsipobranch of the genus {Petromyzon}, and
allied genera. The lampreys have a round, sucking mouth,
without jaws, but set with numerous minute teeth, and one to
three larger teeth on the palate (see Illust. of
{Cyclostomi}). There are seven small branchial openings on
each side. [Written also {lamper eel}, {lamprel}, and
{lampron}.]
Note: The common or sea lamprey of America and Europe
      ({Petromyzon marinus}), which in spring ascends rivers
      to spawn, is considered excellent food by many, and is
      sold as a market fish in some localities. The smaller
      river lampreys mostly belong to the genus
      {Ammoc[oe]les}, or {Lampetra}, as {A. fluviatilis}, of
      Europe, and {A. [ae]pypterus} of America. All lampreys
      attach themselves to other fishes, as parasites, by
      means of the suckerlike mouth.