Why Do Ember Tetras Chase Each Other?

Ember tetras are one of the most popular freshwater fish in the hobby. They come in many bright colors, have a peaceful temperament, and are easy to maintain. The downside is that they can be aggressive towards each other at times. Many aquarists wonder why do ember tetras chase each other? There are many possible reasons for this behavior that we will explore below!

Ember tetras will chase each other during courtship and mating. This is normal behavior. The female follows the male while he defends his territory by chasing her away or through it! Eventually, they will pair up in a breeding ball before spawning together.

Ember tetras will chase each other to show dominance. Ember tetras are schooling fish, meaning they should be kept in groups of six or more. The leader is the largest and most dominant fish in the group. It’s common for lower-ranking ember tetras to challenge them by chasing often!

In this blog post, we will give you reasons for why ember tetras chase each other, in addition to tips on how you can stop them from fighting. We will also cover FAQs, which are important things that many people ask about when it comes to this topic!

Reasons Why Ember Tetras Chase Each Other

Ember tetras are schooling fish and will not be happy unless they are in their school. As a result, they often attack each other when the school is broken up, even if it’s just to rearrange themselves into a new formation – this can result in injured or dead tetras, especially with bigger schools.

Courtship And Mating

Although Ember Tetras do not have any way of communicating, they can still display some interesting courtship rituals.

For example, when a female is ready to mate, she will swim upside down in front of the male while fluttering her fins and tapping on the bottom of his aquarium for him to notice her.

If he accepts, he will follow closely behind as they swim to the water’s surface, where he will fertilize her.

To Show Dominance

If a new fish is introduced into an Ember Tetra school, the most dominant ones will attack it first. This shows that they are both fit and strong enough to defend their territory from intruders before chasing them out of the area.

Although they are schooling fish, Ember Tetras also have a pecking order in their school, often displayed by chasing each other. Generally, the more dominant tetra will be at the top while others will follow behind or swim on their tails to gain dominance.

Incompatible Personality

Although it is unknown why sometimes two tetras of the same sex will chase each other and even fight, this can result in injuries or death for one or both of the fish involved!

Just like humans, not all tetras have compatible personalities. Ember Tetras are very active and enjoy swimming around their tank as much as possible. Incompatible personalities can cause a lot of stress for both the tetra and any other fish in the aquarium, which will usually result in them chasing each other.

Competition For Food

They may also be chasing each other because there isn’t enough food to go around for all of them. This can result in them being competitive and often chasing each other off the best parts before they get there first.

Tetras love to eat anything that falls into their tanks, including flakes, pellets, bloodworms, and brine shrimp. However, if there is not enough food to go around, Ember Tetras will start chasing each other for whatever little morsels they can get their mouths on first.


In an aquarium environment, one or more tetras may become overly aggressive because they feel their territory is being threatened by another fish swimming too close.

Ember tetra fish are very territorial; however, you shouldn’t be concerned about killing or seriously injuring another tetra because of it.

Rather than showing any malicious intent, they are simply trying to show their dominance over the other tetra and establish a hierarchy within the school which each member can follow without question.

Bad Water Parameters

Although Ember Tetras aren’t very fussy about water parameters when kept in an aquarium, they will not be pleased if the conditions do not meet the requirements of their natural habitat.

Ember Tetras are endemic to South America and originate from clear, slow-running water streams where temperature fluctuations occur frequently. In an aquarium environment, though, these fish should ideally have a steady tropical temperature between 22°C – 26°C (72°F – 79°F) and a pH of around neutral.

If water parameters are not at the correct levels, this can result in fish becoming highly stressed, and they may be more inclined to chase each other. Bad water parameters include:

  • High/low pH
  • Unsuitable temperature (too hot or too cold)
  • Poor oxygenation of the tank water – low dissolved oxygen levels
  • Overcrowding of the fish population in their tank
  • Poor water quality – high ammonia, nitrite, and nitrogen level


Perhaps the simplest answer as to why Ember Tetras chase each other is because they are simply playing!

Ember tetras are very active fish who often enjoy playing with toys or other aquarium decorations. Unfortunately, this can result in them chasing each other around just because they are having fun!

Ember tetra fish have a very playful nature, and it’s not unusual for them to swim around their tank chasing each other, dashing in and out of plants, or generally having fun with whatever toys you may have provided.

Although this is in no way an aggressive act, it can result in one or more of the tetras becoming injured.

How Can You Stop Ember Tetras From Chasing Each Other?

The best way to stop your tetra from chasing each other is to ensure they have everything they need and, if necessary, add more fish into the tank with them.

Sometimes you will end up with incompatible personalities, or another fish that has been introduced into their environment may be chasing them around.

You can also remove the fish chasing your other tetra, but make sure you do it safely and carefully not to hurt or stress your tetra further.

If all else fails, then some types of medication may work for this problem. However, these methods should only be done as a last resort.

You could also try adding plants into the tank to give your tetras somewhere to go that isn’t full of other fish or smaller tetra larger ones chasing!


Can Ember Tetras Kill Each Other?

No, Ember Tetras cannot kill each other in the wild or aquariums. They do occasionally fight with one another, but it is not to the extent of killing each other.

Can Ember Tetras Live With Other Fish?

Ember tetras can live with other fish. However, they tend to be aggressive towards others, so you should only place them in aquariums where there are no small or slow-moving fish, and if they share a tank, make sure the tank is at least 20 gallons.

Ember tetra can live with fish that are of similar size and temperament. These include guppies, Platy fish, swordtails, mollies, angelfish, and gourami. However, they should not live with other tetras that have similar colors or body shapes.


In conclusion, there are many reasons why Ember tetras will chase each other. A lot goes into the decision to start chasing another fish, which can be different for every case. Some actions you might take include getting them more room in their tank or putting up barriers between your tanks if they are too aggressive with one another. By doing this, you should be able to stop Ember tetras from chasing each other.

If you have questions or want to leave feedback, let us know in the comment section below.