Platies and Baby Platies

So we have a 10-gallon fishtank currently residing in our kitchen. Paige got it for her dorm room and lugs it back and forth between home and school. We have four adult fish: a silver lyretail molly, and three platies, a male redwag platy and two micky mouse platies, one male and one female.

The female mickey mouse platy appears to have produced some babies, of which two have survived (platies are notorious for eating their fry). Paige thinks both babies are female. One can sex them by examining the anal fin. In the female, it's fan-shaped; in the male, the anal fin, or gonopodium, is tube-shaped.



Here is the bigger baby with one of the adult platies:

Our bigger baby platy with an adult                                          

The tiny baby is prudently reclusive, but I managed to get a photo of her. As you can see, she doesn't have much color and is rather diaphonous.

The tiny baby

       
The gestation period is apparently 28 days and the babies can't reproduce until they're about four months old, so I think Mama must have produced the littler baby in a second litter. I'm just surprised because the two babies don't look as much as 28 days apart in age. Maybe the second one is just a runt. In any case, we are likely to end up with lots of inbred platies.

I don't know if Mama is pregnant again. There doesn't seem to be any clear way to tell, although apparently if there are male and female platies in a tank, it's very likely that all of the females will be pregnant. As the females get very close to delivery, they get a dark spot near their anal fins and their stomachs "square up".

Platties are viviparous or live-bearing. Here is some video of a platy giving birth.