We are always told not to put crappie in a small pond because they will overpopulate it and stunt. What is it about crappie that make this so compared to bluegill?
Do they spawn even more and have more babies than BGs?
Are their offspring harder to catch and eat by predators?
They don't grow a great deal larger than BG, do they grow faster and spawn sooner?

Not trying to upset the conventional wisdom. Just wondering what the difference is.