Source : Webster's Revised Unabridged Dictionary (1913)

Spawner \Spawn"er\, n.
   1. (Zo["o]l.) A mature female fish.

            The barbel, for the preservation or their seed, both
            the spawner and the milter, cover their spawn with
            sand.                                 --Walton.

   2. Whatever produces spawn of any kind.

Source : WordNet®

spawner
     n : a female fish at spawning time