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Black Skirt Tetra Being Aggressive

Black Skirt Tetra being aggressive

One of the most common behaviors that people notice in their Black Skirt Tetras is aggression. If you aren’t used to aggressive fish, then it will probably take you by surprise when you start noticing the Black Skirt Tetras nipping at other Tetras, or even some of the other fish in the tank. So, why is this happening? Are you going to have to resign yourself to aggressive Black Skirt Tetras for the life of the aquarium? Let’s take a look. 

Why Are My Tetras Being Aggressive?

To put it simply, it is because Black Skirt Tetras are naturally aggressive fish. They love to fight. They love to nip each other. They love to nip other fish. Honestly, if your Black Skirt Tetras are not being aggressive, this is probably going to be a bigger cause for concern. It is what they do.

There are cases where the fish may be a little bit more aggressive than normal, though.

For example, if you have more male Tetras in the tank than females, then the males will start to compete for the little attention that there is. A lot of people have found that they are able to drastically reduce Tetra aggressiveness by ensuring that they have an equal number of males and females in the tank.

In addition to this, there may be a lack of food, or the Tetras believe that they have to compete for resources in the tank. If you notice that a good amount of the aggression is happening around feeding time, then there is a pretty decent chance that this is the reason.

Of course, it may also be due to the amount of space in the tank.  A small group of Black Skirt Tetras will need a tank size of at least 15-gallons, more if you have other fish in there. However, the more space that you have in that tank for the Tetras, the better is going to be for your fish. So, always buy the biggest tank that you can afford.

The reason why the Tetras tend to be a little bit more aggressive when the tank is smaller is due to the fact that these fish can be pretty territorial, particularly when you have a lot of males. While the tetras will be more than happy to swim around with each other most of the day, eventually they need their own space to chill out in, and they will designate their own territory for that.

Remember, you are not going to be able to completely eliminate the aggressiveness in your Black Skirt Tetras. This is always going to happen. The best that you can hope for is to try and reduce the aggressiveness by as much as possible. In most cases, this means evening out the sex of the fish or, better yet, ensuring that the Tetras have a lot of space that they can move around in.

Do Black Skirt Tetras Nip?

Yes. Black Skirt Tetras nip. In fact, this is what most people notice when the fish are acting a little bit on the aggressive side.

It is rare for Black Skirt Tetras to nip other fish, though. In most cases, they will only nip their fellow tetras. This likely indicates that the fish are competing for space or resources with one another.

While the fish are always going to be nipping each other a little, if the Black Skirt Tetras start to get too aggressive with one another, it may disturb the other fish in the tank. This means that you are going to need to come up with ways that you can rectify the problem. 

Which Fish Get Along With Black Skirt Tetras?

Smaller fish with long fins are pretty much a no-go when you have a Black Skirt Tetra school. As we just said, these fish tend to love to nip away at the fins of other fish, and smaller fish with long fins tend to be at the risk of being bullied, even if the Black Skirt Tetra doesn’t normally attack fish outside of its own species.

A lot of people will pair the Neon Tetra and the Cardinal Tetra with the Black Skirt Tetras without any issues. However, you should probably bear in mind that because these three species share a roughly similar diet, you are going to need to put in extra effort to ensure that there is another food heading into the tank.

Some people will also pair their Black Skirt Tetras with Kuhli Loaches or the Horsehead Loach. You may even want to pair them up with smaller catfish e.g. the Corydoras Catfish. 

If you are looking for a tank mate for the fish, then consider the following:

  • They should require roughly the same tank conditions (i.e. right pH, water temperature, water hardness, etc.)
  • The fish that you select shouldn’t be too aggressive. It will cause a lot more anger in the tank.
  • The fish are slightly larger than the Tetras or, at the minimum, do not have long fins. 

Can Black Skirt Tetras Live With Guppies?

Yes. Black Skirt Tetras should be more than fine living with guppies.

You may find that the Black Skirt Tetras may nip at the guppies if there isn’t a huge amount of space in the tank. However, if the tank conditions are just right, then you will likely notice that the guppies have absolutely no issues with the Black Skirt Tetras. Everybody should just be swimming around in peace.


It is perfectly normal for your Black Skirt Tetra to be aggressive. It is in their nature. However, if the aggression is constant, then it is likely going to be down to poor conditions in the tank. For example, there may not be enough food to go around, the males are competing for females, or the tank is just too small.

Remember, Black Skirt Tetras tend to only be aggressive towards their own species. However, if you notice serious aggression towards other fish, then you have major issues. This will normally be a space issue. 

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Hello, there. Welcome to my blog. I am Erik and I’m the main editor of Sealife Planet website.

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