Well, if your interested in breeding them, then the mother will have her babies at night, so that kind of helps if the clownfish are asleep. And the clownfish pick at he babies very slowly, one every 10 seconds. If you put a flashlight/nightlight at the top, the babies will get attrated to it, then you can remove them with a turkey baster, if you want to breed them, which is quite easy.
Anyway, I just saw something really strange, the mother that has had her babies three days ago is pregnant again, but the strange thing is, the other peppermint is pregnant too! He looks like he'll have babies in the next 3-6 days, though its really hard to predict when. So I guess they can change sexes/store sperm and keep having babies.