I have heterandria formosa. They will eat their fry though not aggressively enough that it is immediately obvious. Without hiding places fry won't make it to adulthood.
This page repeats the general advice when keeping livebearers which is to have more females than males to minimize the stress to the females from the constant sexual advances of the males. This is unneeded with this species as the males are 1/3 the mass of the females and the females easily drive the males off when bothered. Keeping them in a 1 to 1 sex ratio is not a problem at all.
- That's cool to know, of course some people may have different experiences! As with all livebearers, dense hiding places are a must even if they reportedly don't eat their fry. --Cat 12:07, 26 May 2010 (UTC)