I think they're called either. I used to have a couple of them. I don't know whether they were inbred or what but both of them grew funny. One had a crooked spine and the other ended up with this enormous hump on its back and its tail ended up bending down towards the bottom of the tank and it had trouble swimming.
Gorgeous little fish though. If I ever got them again I'd look a little closer though
Where did you get them??