Here's why:
* Territorial: Angelfish are known for being territorial, especially when it comes to their breeding grounds.
* Aggressive: They can be aggressive towards other fish, especially those that look similar to them.
* Pair bonding: They form strong pair bonds and often stay together, rather than forming larger schools.
However, there are a few exceptions:
* Juvenile angelfish: Younger angelfish may sometimes school together for protection.
* Large aquariums: In very large aquariums with ample space and resources, angelfish may be less territorial and more likely to interact with other fish in a group.
In conclusion: While angelfish can occasionally be seen in groups, it's not their typical behavior. They are generally solitary or live in pairs.