it possible that a spawn of 70 fry could all be
A: Well Melynda, the only thing I am actually 100% sure is that when it comes to bettas ANYTHING is possible !!!! LOL
How can such great
So logic may assume that in a spawn of 70 fry you have 70 times the opportunity to produce a male. Human logic, that is. Betta logic however is quite different. There has been much speculations as to why spawns sometimes yield mostly males or females. Many theories have been presented, none of which substantiated, and to mention but a few: water PH, age of the breeders, zodiac sign of owner (just kidding) LOL. The truth is that we really do not have a clue as to why some spawns are female heavy or male heavy. So is it possible that an entire spawn yield only one sex? Unlikely, yes, impossible, no.
In my personal experience, I have seen smaller spawns yield only one female, but have never had an entire spawn just one sex. So here are a couple of things to consider:
Spawns that are out of balance sex wise can cause some logistics problems. An all female spawn may be easy to deal with since you can pretty much keep all the gals together in one large tanks, for a fairly long while. On the other end, an all male spawn may be enough to drive a breeder to the brinks of insanity. One may not be prepared and be short of jars, or shelf space. Suddenly there are jars and bettas everywhere, bathroom, kitchen, bedrooms, library, etc :))... Divorces usually promptly follow LOL.
Well, goodluck with your (possible) betta harem, but like I said, if they are still young, you very well have quite a few males in the bunch, they just haven't popped up yet :). Goodluck :).