Betta fish are known for their intense reaction when put in the same bowl as another betta. In reality, it is only the male betta that are aggressive. They will fight to the death on most occasions, or at least leave each other torn and tattered. The females may be raised in an aquarium together and do not need to be separated. These small, colorful fish may be bred in captivity if carefully watched for the female's reaction to the male betta's aggressive mating behavior.
How to Breed Betta Fish
Place the female and male betta in separate bowls. Give them both plenty of good quality betta food and watch for the female to produce eggs and the male to begin making a bubble nest in one area of the tank.
Place the female betta in the bowl with the male betta and watch them closely. The male will advance aggressively. If the female continues to back away from his advances for several minutes, and is not responding to him, take her out of the bowl and try again in a few days.
Once the eggs have been fertilized, remove the female and place her back in her bowl. The male betta will not tolerate the female for long.
Place a handful of dried straw in a bowl of water with a lid and set it in a sunny windowsill. You'll use the wet straw later to nourish the hatchlings.
Watch for the hatchlings to appear. The small hatchlings should hatch in about two days. Watch for them and remove the male once the hatchlings hatch. He may decide to eat the hatchlings if allowed to stay in the same bowl for long.
Place the wet straw into the bowl with the baby bettas. Watch them during the next few days and add more soaked straw to their bowl. They will eat it for nourishment. In two weeks, start feeding them dried flake food.