My guess is female veiltail. Keep me posted!!!!!
Thank you! I'm going to hold out hope, but if they both end up boys I might just end up with a 10 gallon divided tank, because it's still only two tanks right?I see ovaries which are the only way to tell the sexes. And there are other little subtleties like the small eyes; compare Theta's eyes to my Radar. Radar has much larger eyes than Theta. Also notice the anal fin, it's much more rounded than Radar's anal fin point.
Fingers crossed!Theta looks like she could be a marble betta.