It's been several years, but Dad had the same situation at his pond. He had 7-8 bass (3-5 lbs.) that he had trained to eat bluegill like that. He would cut a few fins off to keep them from immediately swimming away, but once they learned the game, they would be knocking heads trying to get to them before they hit the water. All you had to do was walk up to this one spot and stand there and they would start swimming back and forth in front of you, waiting. Looked exactly like that.