My Swordtail Fish

Question
I have 2 black swordtails, and my female swordtail had some babies, but we only found 1 alive. She is still really big, like she's still pregnant. Can she have 1 baby like that, and then the rest later? Now that I look at her closer, it looks like her top fin is starting to unattach from the back. Could this mean something, like a disease, or toxic waste, or something? Please help. Thank You.
         -Nikki

Answer
Hi Nikki;

Swordtail moms can indeed have babies later on after one or more are delivered. The eggs inside her may have been fertilized at different times so they mature at different times. Keep in mind that any of the fish, including the mother, will eat babies. Just provide lots of hiding places for them.

Her top fin may have been injured. Keep the tank water very clean by making a 25% water change at least once a week and vacuuming the gravel. It will help the babies grow, keep your fish healthy so they can fight disease and help avoid infection if they get injured.

At Your Service;
Chris Robbins