Whenever I try to photograph them they don't show up.. being so small and invisible.. When I saw one of the newborns I thought it was a small piece of human hair that had gotten stuck inside the tank. When I see one, it's usually hanging onto the side of the filter or thermometer.. I usually don't see 'em because they hide in the java moss. I have several young ones who just recently started coming out and mingling with the adults..they are about 1/3 the size and about 3 or 4 months old, I think.
What your describing is what happened to mine as well.. when I switched them to brackish they actually had babies.. I just had another set let loose yesterday and they were at it trying to make more yesterday evening!