Adult molly fish size might reach three to five inches long. Depending on the breed of molly, your fish may not get this big. Sailfin mollies are typically larger than other types.

Female Mexican molly fish tend to go for big, colorful males, so what's a scrawny, drab guy to do? Scientists say he can flaunt bisexual behavior to bag a mate. Among Mexican mollies (Poecilia ...