Found this fish living in my pond a while back, he must have gotten mixed in with a batch of feeder guppies we picked up to feed our bass, bluegill and crappie. he was fast enough to avoid getting eaten, and now he is doing fine in my tropical community tank, so i guess he does okay in cold and warm water. He also loses his black stripe on the side at night. and somtimes lookes purple. Eats tropical flakes and sorta just hangs, but it irks me not knowing what he is.