Here's why:
* Aggressive Nature: They are known for their aggressive behavior towards other fish, especially males. This aggression stems from their territorial nature and instinct to defend their space.
* Fin Nipping: Even if they don't fight outright, they may nip at the fins of other fish, causing stress and potential injury.
* Stress: Being in a tank with other fish can cause significant stress for fighting fish, potentially leading to health issues.
* Compatibility: Their natural habitat is small, isolated areas, and they are not naturally social fish.
Exceptions:
* Specific Species: Some species of fighting fish are known to be more peaceful than others.
* Separate Tanks: If you want to keep multiple fighting fish, you should keep them in separate tanks.
* Community Tank with Extreme Caution: It is possible to house a fighting fish with other fish, but only under very specific conditions (like a large, planted tank with lots of hiding spaces and very specific fish choices), and even then, it's a risky endeavor.
In short, it is generally not recommended to keep a fighting fish with other fish. It's best to keep them individually in their own tanks to ensure their well-being.