I had a crowntail, which I bought at Petco, and found out too late that they were inbred for their tail shape. Now they are their own breed, I guess, but I would not get one if I were you. The inbreeding led to them being very, very aggressive. This did not really matter, I thought, as he lived in a bowl where he couldn't hurt anyone. But, a few weeks ago, he started to become a little psychotic. He would suddenly start to swim very fast, in strange patterns, and even jump out of the water a little. Last night, I guess, he jumped a little too high. This morning, he was not in his bowl. This evening, we found the body.
I wonder whether the angry disposition of the breed had anything to do with his actions of late, and I urge you, if your heart is set on a crowntail, keep the tank covered with netting or a strainer or something.