Visit the spawning locations.
Angel-type
Females - May only breed once in any spawning, no exceptions.
Males - Anything past two fatherings in one spawning and there is a very real risk the breeding could fail completely.
Result - One egg per pair is the norm, twins are rare. The egg goes with the mother, unless she was bred to a Betta male, then he gets the egg.
All gender chances are 50/50 for angels. Genetic inheriting based on breeding location.
Betta-type
Females - May only breed twice in one spawning, no exceptions.
Males - Are so very lazy it's a surprise to get them to breed once. Anything past three fatherings in one spawning and there is a very real risk the breeding could fail completely.
Result - One egg per pair is the norm, twins are rare. The egg goes with the father, who defends it furiously, even from the mother.
Genetic inheriting and gender is determined by breeding location.
Hybrids
All breeding across types results in a hybrid who may at any time spawn the type of either parent, or a visible hybrid - they are never a pure type again.
The chance for a visible hybrid increases per desirability of spawning location. There is no way to guarantee a visible hybrid, or what this mix will look like.
