The Collaborative International Dictionary of English v.0.48:

Scup \Scup\, n. [Contr. fr. American Indian mishc[`u]p, fr.
   mishe-kuppi large, thick-scaled.] (Zool.)
   A marine sparoid food fish (Stenotomus chrysops, or
   Stenotomus argyrops), common on the Atlantic coast of the
   United States. It appears bright silvery when swimming in the
   daytime, but shows broad blackish transverse bands at night
   and when dead. Called also porgee, paugy, porgy,
   scuppaug.
   [1913 Webster]

   Note: The same names are also applied to a closely allied
         Southern species (Stenotomus Gardeni).
         [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Porgy \Por"gy\, n.; pl. Porgies. [See Paugie.]
   1. (Zool.)
      (a) The scup.
      (b) The sailor's choice, or pinfish.
      (c) The margate fish.
      (d) The spadefish.
      (e) Any one of several species of embiotocoids, or surf
          fishes, of the Pacific coast. The name is also given
          locally to several other fishes, as the bur fish.
          [Written also porgee, porgie, and paugy.]
          [1913 Webster]

   2. (Zool.) Any one of numerous sparoid food fishes, as the
      jolthead porgy, the sheepshead porgy (Calamus penna) of
      the West Indies, the grass porgy (Calamus arctifrons) of
      Florida, and the red porgy (Pagrus pagrus) of Europe.
      [Webster 1913 Suppl.]