Ok, so what should I do? I don't know if the mom is alive or dead since I can't figure out how to identify the sex. Does that even matter at this point? And I don't really have the ability to get a second tank right now for frys (though in the future that sounds like a good idea). Where else can I keep this little one safe until it's bigger?
Female Platy: Anal fin looks like a fin. My female red wag the anal fin is black.
Male Platy: Anal fin looks more like a tube then a fin. In my male red wag platy the tube is white. There is a name for this tube but I don't know how to spell it.
That's the easiest and most reliable way to tell the difference imo.
As far as the fry goes I've had a fry in my tank now for about 2 months that survived to be big enough that I'm not overly afraid of him/her being eaten. However I started with about 7 fry at least that I could see. I haven't really paid attention to the fry since I got them the day after I brought the platy home so wasn't ready for them.
Would a small desk fish tank (1g or less) with a sponge filter and nightlight bulb work for a month or so till the fry gets bigger? I think you can pick those up at walmart or a commercial pet store for less then $10.00, UGF or sponge filter, small air pump, hood and light included. I personally don't like them but when we are talking about a 1/4" fish it might be okay.
Or a 2G hex for less then $20.00. If you decide to spring for a 2G hex you can use it as a betta tank later. I have three of those and my Betta seem to love em.
For the smaller tank just syphon out the trash with a turkey baister, much easier then a gravel vac on a tank that small. The 2G tank is okay with my python gravel vac, but sucks water almost too fast to do a good cleaning by the time the water is 50% gone.
If the tank has a sponge filter I wouldn't go substrate, just cause it's easier to clean the tank bottom. If the tank comes with a UGF I don't think that a cheap sponge filter costs very much additional and the pump for the UGF will power a sponge just fine. Save the UGF for when you set up the tank with substrate, or just trash it and keep using the sponge.
I would throw in a small plant or two just so the fry has somewhere to hide and play.
Since it is such a small tank (both the <1g and the 2g hex) and you already have the fish then I would do frequent water changes. Every other day probably just because you don't want a nitrogen cycle to kill your fry. Of course you can fill with water from your exsting tank and use some squeezings from your existing filter media to seed the tank. Watch the temp on the water changes though, that small of a tank the temperature could fluctuate a lot more very quickly. I'd age some water in a pitcher, then it would be room temperature when added to the tank, or keep filling with water from your established tank.
Also food: If the fry is as big as you say already he should be able to eat flake food, just crush it up small. I figure that's what my fry has been eating for the last month or so, the very very small flakes that the other fish miss.
Only other concern I can think of is bacterial, fungus, and algea problems but over the counter tank medications seem to be fine for those. Just read the directions carefully. Dosing a <1g tank will probably be very difficult, think in drops, not in scoops.
I would ask for a second opinion on my opinions though as I am pretty new to this still and haven't gotten into the breeding thing...yet.
