Why do male siamese fighter fish?
Woodchipper890 is correct. A male & female betta should never be placed in the same tank unless BOTH of them are ready for breeding. The male has to have built a bubble nest and the female should have a swollen belly & stripes on her body. When the female is ready, she would be willing to seek out the male instead of running away or fighting with him. After the fertilised eggs are placed in the nest by the male, the female must be taken out or the male will attack her. But DON’T put a pair together unless you’re prepared to care for hundreds of betta fry as the female may lay up to 500 eggs. When it is possible to identify juvenile males, you would need separate tanks for each male to prevent fighting. So betta breeding is not something to be undertaken lightly by home aquarists. As for the gill puffing, the male is trying to make himself look bigger by flaring his gill covers & fins. This is to intimidate the opponent (remember a female is also his enemy unless they’re ready to breed)
