That is so Cool an thank you so much for your time and knowledge I reallyThe baby is a pearl. So the dad must be a pearl to pass the pearl gene , or split to pearl. sex linked mutation : dad must have the gene to pass to offspring. All females will visually show mutation, all males will be split to the mutation unless mom also has the gene, then males will have the mutation as well.
both lutino and pearl are sex linked. That is why the breeder can determine it is a boy, all the baby girls must be lutino as mom is not lutino but dad is. Then by process of elimination, all males are not lutino.