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Will Angelfish Kill Each Other?

Angelfish have long been a favorite among aquarium hobbyists. Their elegant and graceful movements along with their vibrant, colorful patterns make them a great addition to any freshwater tank. But what about their demeanor? Are they aggressive and could they attack or potentially kill each other in a community tank environment?

Since angelfish are a type of cichlid, you’d assume they’d be aggressive in nature like most cichlid species. However, angelfish are the exception to the rule and are usually quite peaceful, though they can become territorial when kept in a smaller tank. Because they have small teeth, it’s unlikely they’d kill or severely harm each other (or other fish) in a community tank.

Now that you know angelfish are the most docile when it comes to cichlids, let’s explore this topic further. In this article, I’ll discuss whether (or not) angelfish fight each and if so, how to prevent it from happening. I’ll also explain if it’s okay to keep 2 or more male angelfish together in the same tank and what size aquarium is best for multiple angelfish.

So, if you’re ready to learn more about angelfish and their behaviour towards each other in an aquarium, then let’s get started!

Do Angelfish Attack Each Other?

While angelfish tend to be the most peaceful of cichlid species, they can get territorial and aggressive if 2 or more males are kept together in the same aquarium. They may even chase or fight each other to win favor among the females. Though not likely to fight to the death, they can still inflict injury to one another should a battle to mate ensue.

Do Angelfish Fight to the Death?

Fighting to the death isn’t typical for angelfish. However, that’s not to say it can’t happen, especially if 2 or more are kept together in a smaller tank. To prevent this from happening, you should only have a single male in an aquarium at any one time. Adding 1 or 2 females is okay, provided you have a big enough tank – for a pair of angelfish, you need at least a 20-gallon size, though bigger is always better.

Why Are My Angelfish Attacking Each Other?

When angelfish appear to be pecking or nipping at each other, it’s usually a sign of aggression, especially if you have more than 1 male in the tank. Male/female pairs will also ‘attack’ each other by locking lips or posturing/twitching usually right before spawning. If they demonstrate this behavior after spawning, it’s typically after they’ve eaten the eggs.

Why Do Angelfish Fight Each Other?

Two or more female angelfish won’t fight each other in the same aquarium. Two or more males, on the other hand, will and often do. In most cases, the dominant male will bully or attack the weaker one to assert his territorial claim. The only way to keep more than 1 angelfish male in the same tank at the time is to have a very large tank – at least 100 gallons or bigger is recommended.

How Do You Stop Angelfish from Fighting?

To prevent angelfish from fighting each other in an aquarium, you must keep them in a large tank. The rule of thumb is 10 gallons of water (at the very least) for each angelfish in an aquarium. The best way to prevent fighting is to keep only females or a few females with a single male. Try not to confuse fighting with mating, as males will often chase after the females in an effort to breed with them.

You can also try rearranging the tank or adding new plants and decorations. This changes the ‘lay of the land’ and confuses the angelfish, making it harder for them to assert their territorial claim. While they’re taking the time to explore their ‘new’ surroundings, they likely won’t have the desire to fight with each other. Be cautious when moving things around so as not to spook the fish or possibly cause injury.

Another option is to introduce a new fish to the tank. The black convict or zebra fish is a fast and tough species of cichlid, able to hold its own against the more-timid angelfish. Larger tetras, rasboras or discus fish will also help curb angelfish aggression, making them the ideal choice for tankmates. Be careful when adding small fish to an angelfish tank, however, as they will eat any fish that fits into their mouths!

If all else fails, you can split-up the male angelfish into different tanks or you can put a divider in your aquarium. Dividers attach to the top and bottom of the tank via suction cups and are used to separate aggressive fish, for breeding purposes or for raising fry. They come in different sizes and are available online through Amazon. I recommend the Shiroumiya Aquarium Fish Tank Acrylic Divider.

Are My Angelfish Fighting or Mating?

The mating ritual for angelfish can sometimes appear as bullying or fighting. This includes the males frantically the chasing the females about the tank. Should you notice this erratic behaviour followed by 2 angelfish locking lips or ‘kissing’, it’s probably a male and a female trying to breed. If you notice this happening with 2 males, then chances it’s likely a confrontation.

Can I Keep 2 Male Angelfish Together?

The only way to keep 2 or more male angelfish together is to place in them a very large tank. I would say anything less than 100 gallons is too small for multiple angelfish. A small tank environment often leads to increased stress and aggression among what are typically a docile fish. A big tank allows each male a space or territory to call his own.

How to Calm Down Angelfish?

There are 5 main ways to reduce angelfish aggression in an aquarium. These include the following:

  • Keep the number of males and females balanced (or in pairs) – if you have too many females, then they may become aggressive when comes time to lay their eggs. Too many males will lead to fighting and chasing, both of which are signs of aggression.
  • Have smaller schooling fish in the tank for the angels to chase around – this prevents them from chasing or bullying each other. Larger, less aggressive fish or fish or similar size that can hold their own will also help keep angelfish aggression levels at bay.
  • Keep angelfish in as big a tank as possible – a large aquarium with plenty of space for fish to swim and explore helps reduce stress that can ultimately lead to aggression. A tall 30-gallon tank, for example, is perfect for 2 angels.
  • Add plants and decorations for shelter (hiding places) – this enables angelfish to have their own space or territory to retreat too – a large open tank will lead to aggression as each angel will have no choice but to ‘fight’ and defend the only space in the tank.
  • Make sure your angelfish are healthy and well-fed – stressed out, malnourished fish will fight more frequently. Fin rot, which is a symptom of a poor diet and occurs when fish fight and nip at each other, is also more prevalent. Luckily, it’s easily treatable with the right medication.

How Do Angelfish Act When They’re Dying?

If your angelfish is dying, it’ll likely stop swimming and gasp for air near the surface of the tank or lay motionless on the substrate at the bottom. It may also refuse to eat and show physical signs of illness such as nipped fins or skin sores. Diseases such as hexamita or ich, both caused by parasites, are common causes of angelfish death.


To conclude, angelfish are a type of cichlid and therefore predisposed to a certain level or aggression. That said, they’re still the most peaceful of the cichlid species and often get along well with each other (and other fish) in a community tank environment. They have tiny teeth which prevents them from causing serious harm or death to one another angelfish, even when nipping or fighting.

I hope this article has provided you with the information you seek. Thanks for reading and good luck with your freshwater cichlid aquarium.

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