Since bettas are domesticated, the entire health of their species is in our hands. It is not accepted in the hobby to breed rosetail or feathertail bettas because they have many many genetic issues, such as missing scales, SBD, etc. It is important to breed bettas that will give them good genetic genes, to protect their species. This leads me to a rather unpleasant topic: culling. When breeding bettas, you will likely have to kill, known as cull, unhealthy, or deformed bettas. As unpleasant as this is, it must be done.