Some times its pretty easy too for a crested to lose its tail. When they are usually babies they lose it from other tank mates. Other cresteds. My first one came from John Watson. He gave me a dalmatian cream colored crested in trade for art for him. And I later decided to sell the crested for some bill money and right before I was to put the crested in the box to ship it , the thing escaped! We didn't even know at the time that it had escaped though. My husband closed the fridge door and heard a thump, he looked around and the crested was climbing up the wall and fell off the wall. This caused it to lose its tail. It was fine, other then the fact that I guess it fell on its tail and the tail just broke off instantly. I didn't know at the time how it had fell off. Cause I wasn't in the room, but my husband later told me. lol I think he was afraid to tell me that I would get mad at him or something.