aside from the adult female perhaps being larger, you can tell the difference by looking at the female's "saddle" or if she's berried then its very obvious. males will never develop the saddle since they dont have ovaries lol.
Btw it looks like i may be wrong, that vid depicts the newly hatched shrimp as visible to the naked eye. so the parents will probably eat them if not separated. also low current is preferable, and as i said sponge bubblers wont chop up the babies.