A person I know (lives in Nicaragua) has a school of 8 piranhas in a large 1500 gallon pool. While out fishing, he caught a dovii cichlid and thought it'd make a nice live food for his piranhas. So he tossed the 22 inch dovii in with his school of 8 6-8 inch piranhas and, well the dovii killed 5 of the 8 piranhas. I don't know why he thought a large dovii would be food for a school of medium sized piranhas. So yeah...... don't take a large, notoriously tough and aggressive fish and use it as a feeder for smaller, weaker fish.