Boy, I don't know anything about goldfish being snail eating predators. But I do know why shellcrackers are called shellcrackers. I don't figure the catfish will let the goldfish live long enough to do much.

If Bob can't supply the shellcrackers, call Marshall Grain in Fort Worth or Berend Brothers Feed store in Bowie. Ask them about fish truck schedules and call the fish dealer to see if they are hauling shellcrackers.