Don't know...the silvers have always been in a community tank. Eggs are eaten as soon as they're laid. So, I couldn't tell ya if the males are still fertile or not.
My mom bought two 29 gallon tanks several years ago, probably over 4 years anyway. I didn't get into fish until a bit over a year ago, but there is one buenos aires tetra in the 29 that is still set up which is one of the originals.