This isn't Bela, as you can see by the fact that he's a veiltail. I didn't want to be too crowntail-centric. Anyway as far as I know Bela has no children.
As I have mentioned elsewhere, betta eggs and fry are cared for exclusively by their father, who chases the mother away immediately after mating. He tends to them for only a few days, but that's pretty impressive for a fish, I think. I could cross the streams and try to do a joke about how Harry Harlow's initial experiments with bettas were disappointing, but some jokes are too obscure even for me.
Which of my jokes about a maligned scientist is more obscure?
Walter Freeman lobotomizing a headcrab
Harry Harlow giving wire mothers to Siamese fighting fish
Now that I think about it, bettas don't have frontal lobes. That makes them useless to both of my favorite mad scientists. (Though you may recall that Walter did find a use for goldfish, which reminds me that I should work on the lyrics to that song so I can get someone to write music for them.)