killifish

killifish
    n 1: small mostly marine warm-water carp-like schooling fishes;
         used as bait or aquarium fishes or in mosquito control
    

Killifish \Kil"li*fish`\, n. (Zool.)
   Any one of several small American cyprinodont fishes of the
   genus {Fundulus} and allied genera. They live equally well in
   fresh and brackish water, or even in the sea. They are
   usually striped or barred with black. Called also {minnow},
   and {brook fish}. See {Minnow}.
   [1913 Webster]
    

Minnow \Min"now\, n. [OE. menow, cf. AS. myne; also OE. menuse,
   OF. menuise small fish; akin to E. minish, minute.] [Written
   also {minow}.]
   [1913 Webster]
   1. (Zool.) A small European fresh-water cyprinoid fish
      ({Phoxinus laevis}, formerly {Leuciscus phoxinus});
      sometimes applied also to the young of larger kinds; --
      called also {minim} and {minny}. The name is also applied
      to several allied American species, of the genera
      {Phoxinus}, {Notropis}, or {Minnilus}, and {Rhinichthys}.
      [1913 Webster]

   2. (Zool.) Any of numerous small American cyprinodont fishes
      of the genus {Fundulus}, and related genera. They live
      both in fresh and in salt water. Called also {killifish},
      {minny}, and {mummichog}.
      [1913 Webster]