Source : Webster's Revised Unabridged Dictionary (1913)

Ten-pounder \Ten"-pound`er\, n. (Zo["o]l.)
   A large oceanic fish ({Elops saurus}) found in the tropical
   parts of all the oceans. It is used chiefly for bait.

Source : WordNet®

Elops saurus
     n : game fish resembling the tarpon but smaller [syn: {ladyfish},
          {tenpounder}]