Wow, 2 other people keep their polleni with an orange pike. When I got my Xingu he was much smaller than the Polleni and was chased by him. Recently though, the Xingu has just about caught up in body length, and has turned the tables on the Polleni. Now, whenever the Polleni ventures out of his cave, the Xingu savagely attacks him, not just chasing, real biting. This has me concered. I'm not wanting to get rid of either fish, but I should move one of them to a different tank if I could figure out a suitable arrangement.