Can male and female betta fish be kept in the same tank?

In most cases, it is not advisable to keep male and female betta fish together in the same tank. Male betta fish are known for their aggressive behavior, especially towards other male bettas. If you introduce a female betta into the tank, the male will likely become territorial and act aggressively towards her. This aggression can lead to stress, injury, or even death for the female betta.

Even if you manage to introduce a female betta into the tank without any initial aggression, the male may still become aggressive towards her in the future, especially during breeding season. It is best to keep male and female betta fish separate, unless you have a large tank (at least 20 gallons) that is heavily planted and provides plenty of hiding places for the female. Even in a large tank, it is essential to monitor the behavior of the male and female bettas closely to ensure the female's safety.