Visit the spawning locations.
For all fish: Females may only breed once per spawning. Males may be involved in up to three spawnings.
One egg is the normal result, twins are rare.
Each fish may bring one bauble to each location per spawning (thus a male bred three times may bring three different baubles to each separate spawning).

Angel
All gender chances are 50/50 for angels. Genetic inheriting based on breeding location.

Betta
Genetic inheriting and gender is determined by breeding location.

Carp
All gender chances are 50/50 for carp. Genetic inheriting based on breeding location.

Dragon
All gender chances are 50/50 for dragon. Genetic inheriting based on 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.