One of the things I tend to think about is in the future, making sure the captive animal you just bought is truely a pure line and not a look alike with mixed blood.
I'm not really a fan of the cross breeding. I know it happens by accident and on purpose. I'm friends with a lot who do it for profit. That's their thing, not mine. I've always been very particular with sexually mature rays I keep together for that reason. I've always kept solid records of animals in my care as well. Groups like the TAG and PMP programs that zoos/aquariums use are great tools to track and maintain the genetics well.
Ray breeding is not a mystery like it was 20 years ago. We have the knowledge, technology and ability to do it correctly to maintain the pure lines. We just don't.