A little over two months ago, my friend gave me her ten gallon tank with two black skirted tetras, a swordtail, a dalmation molly, a placo (don't know how to spell its full name :P) and a female betta.
A few weeks later the molly gave birth to a bunch of fry and since I didn't have a breeding trap at the time, I lost a bunch. After getting a trap I managed to save five. One disappeared (I still don't know what happened to it) and three died for some reason. The one I managed to save is now thriving in my mother's much bigger tank.
Then the molly gave birth again (I managed to save all 11 and they are growing fast!) but my filter died as did the one I bought after. I managed to get a new one that works but my molly died the other day.
I have a question, it only took me a couple days to get a working filter, but is that why she died? And if so am I at risk of loosing my fry?
Also one of my tetras suddenly got much bigger than the other one and its belly is getting quite pudgy. How do you tell the difference between male and female? If its a female and she's pregnant can I put her fry with the molly fry(they are still too small for the main tank).
I know I have a lot of questions but I'm new to fish care and am still not quite sure I know what I'm doing.