Why not try and see if they can actually be together.
My LFS worker said that he had a pair and to prevent from death or damage:
They were divided by an egg crate divider. A flat rock slab was put on Female side propped up, angled towards Male side.
So Female laid eggs on the slab. Male on the other side spermed. Get this, he had a powerhead blowing from Male's side and it fertilized the eggs.