[anasfire23]

Swordtailbreedr I think you are thinking more of humans, it's obviously not good for humans to interbreed that's why society has made it such a taboo, but with fish interbreeding is exactly what u want to produce a strong gene line. If you introduce a new fish into the gene line you will be introducing undetermined genes and traits and all your hard work to get a certain trait eg colour will go out the window and can set you back like 2-3 spawns (in reality 2-3 years). There is nothing wrong with breeding siblings, there aren't, to my knowledge, and reports of deformities with sibling breeding only stronger gene lines.