Source : Webster's Revised Unabridged Dictionary (1913)

Whitebait \White"bait`\, n. (Zo["o]l.)
   (a) The young of several species of herrings, especially of
       the common herring, esteemed a great delicacy by epicures
       in England.
   (b) A small translucent fish ({Salanx Chinensis}) abundant at
       certain seasons on the coasts of China and Japan, and
       used in the same manner as the European whitebait.

Source : WordNet®

whitebait
     n 1: minnows or other small fresh- or salt-water fish (especially
          herring); usually cooked whole
     2: the edible young of especially herrings and sprats and
        smelts