Angelfish have a certain territorial awareness and may attack other small fish. They don't have special requirements for water quality, but it's better not to keep them mixed with small fish, especially the tiger barb fish of the Cyprinidae family. Tiger barb fish are lively and active, and they may bite the anal fins and tail fins of angelfish. Although such attacks won't be fatal, to maintain the beautiful appearance of angelfish, it's best to avoid mixing them for breeding.
Besides, the feeding habits of angelfish also suggest that they may attack other small fish. The baits for angelfish include animal baits such as water fleas, tubifex worms, ciliate worms, and mealworms, which indicates that they may prey on other small fish in the natural environment.
To ensure that angelfish and other fish can live in harmony, it is recommended to provide enough water area and food in the aquarium to reduce the occurrence of conflicts.