Are Angelfish Aggressive?

Angelfish typically aren’t aggressive, but they can be aggressive towards other fish in the tank, especially if the tank is overcrowded or there is too little food. They are a bit territorial by nature, and they like to be the most dominant fish in a tank. Aggression amongst angelfish is most common during mating season. 

Keeping the right number of angelfish for the size of your tank is the best way to curb aggressive behavior. This article discusses how to recognize angelfish aggression, the underlying causes, and how to prevent the angelfish in your tank from acting aggressively. It helps to choose the right tankmates!

Are Angelfish Aggressive Towards Other Angelfish?

As a cichlid species, angelfish naturally have a feisty temperament. They are an active, dominant species that are territorial.

Angelfish do not school together, but they are social and live in small groups within the same area. Each group is made up of a dominant male and several females. The male will claim a territory and defend it against other male angelfish.

Territorial behavior is the most common cause of aggression between angelfish. Therefore, it is recommended that you only keep one male angelfish in a tank with a few females.

Mating time is when angelfish are most aggressive towards each other. When angelfish are preparing to spawn, a male and female pair up and claim an area where they will lay their eggs. They aggressively defend this area against other fish in the tank.

Therefore, it is best to separate mating pairs of angelfish and keep them in their own tank.

Close Up of White Orange and Black Angelfish

Are Angelfish Aggressive Towards Other Fish Species?

In the wild, angelfish live in rivers with many other species of fish. They are peaceful fish in their natural habitat, but in the confines of a tank, they can be aggressive towards other species.

Angelfish are sometimes aggressive towards other species of fish in a tank, especially species that are as active and dominant as angelfish. Therefore, it is not ideal to keep angelfish in a community tank long-term.

When you do put angelfish in a tank with other species, you must be very selective about which tankmates you choose. Angelfish cannot be kept with other aggressive and dominant species.

They should also not be kept with fish that are small enough to eat. Angelfish are carnivores, and they may feed on smaller tankmates and fry.

What Are The Signs Of Angelfish Aggression?

Sometimes it is difficult to tell whether fish are fighting or mating! To the inexperienced aquarist, these behaviors look almost identical.

When angelfish pair off to mate, they nip at each other, groom one another, and the male and female lock lips and twist around.

When angelfish fight, they chase the other fish, hit them with their tails, and nip at their fins. You may also see an angelfish having a stare-down with their competitor.

What Causes Angelfish To Behave Aggressively?

There are a few reasons why angelfish may act aggressively towards each other and other fish species:

  • Territorial behavior
  • Mating aggression
  • Stress due to limited food or space in the tank
  • Stress due to poor water conditions
  • Stress due to a disturbance in the tank

How To Prevent Angelfish Aggression

It’s almost impossible to prevent an angelfish from behaving aggressively. It is, after all, their natural temperament. But there are ways to minimize angelfish aggression in your tank:

  • Keep angelfish in a tank that is large enough. They need enough space to establish their own territory. If they have enough room to keep to themselves, you can prevent aggressive behavior for the most part. A group of six angelfish (1 male and 5 females) needs at least a 60-gallon tank.
  • Avoid overcrowding the tank. Do not overstock a tank with angelfish, especially a community tank. Too many fish cause them to become stressed, and this increases the chances of aggression.
  • Never keep two male angelfish together in a tank. They will fight for dominance, and one male will eventually kill the other.
  • Ensure appropriate water conditions. Angelfish can become more aggressive if they are not happy with the water conditions. If the current is too strong, the temperature isn’t right, or the water is dirty, angelfish become stressed and aggressive.
  • Ensure the fish have enough food. Competition for food resources is a major cause of aggression. Hungry angelfish are more aggressive, so make sure you feed them enough!
  • Provide plenty of plants, rocks, and caves as hiding places. Angelfish love to have private areas in the tank to hide away from other fish. Without enough hiding spots, they can become stressed and behave more aggressively.
  • Remove breeding pairs of angelfish and put them in their own tank. Angelfish are most aggressive during breeding time, so it is best to separate breeding pairs from the other fish in the tank.
  • Avoid changing the water too frequently. Too-frequent water changes can cause angelfish to become aggressive. They do not seem to like the disturbance.
  • Remove very aggressive, problematic fish from the tank. If there is one particularly aggressive angelfish in the tank, the simplest way to protect the other fish is to remove the offender.

Tankmates That Angelfish Will Get Along With

It is important to choose the fish you keep with angelfish very carefully. You must avoid tankmates that are as dominant as angelfish because they will otherwise butt heads!

The best fish to keep in a tank with angelfish are large, peaceful species that do not have a habit of nipping at fins.

The following fish are excellent candidates for a community tank with angelfish:

  • Corydoras catfish
  • Otocinclus catfish
  • Kuhli loach
  • Zebra loach
  • Common pleco
  • Bristlenose pleco
  • Rubber nose pleco
  • Dwarf gourami
  • Three spot gourami
  • Tetras
  • Platies
  • Bolivian ram
  • Electric blue ram
  • Discus fish
  • Hatchetfish
  • Guppies
  • Mollies
  • Keyhole cichlid
  • Kribensis cichlid
  • Silver dollar
  • Swordtail


Angelfish are a naturally aggressive species, and it is important to be aware of this before you introduce a few angelfish into your tank. To prevent your angelfish from antagonizing other fish in the tank, you need to ensure that the tank is large enough, there are enough plants and hiding spots, and the water parameters are right.