Are Cardinal Fish Aggressive?

Are Cardinal Fish Aggressive?

All fish has 3 temperaments, those that are very aggressive, those that are semi-aggressive, and those that are very peaceful. If you are reading this article, it means you want to know if Cardinal fish is aggressive or peaceful. Cardinal fish is a nice fish to have in the aquarium and they are full of activities but the question is, are they aggressive? you will find out in this article and many more.

Are Cardinal fish aggressive? Yes, Cardinal fish are very aggressive and territorial. They hardly tolerate their kind.

Cardinal fish are very aggressive fish, although it depends on the particular specie because there are few Species of Cardinal fish, some are very intolerant and some could tolerate themselves.

For instance, specie like the Banggai Cardinal fish are very territorial and could kill others while species like the Threadfin Cardinal fish are very peaceful and tolerant, so if you ask me, it depends on the particular specie you want to keep.

Again even though the fish is territorial and aggressive or peaceful, the size of your tank plays a very important role in their overall coexistence.

Aggressive and territorial Cardinals like the Banggai Cardinals are known to kill each other, especially the third fish or the latest or newest fish in their tanks.

They seem to coexist more when they are two in number and in a sizeable tank too.

So, Cardinal fish are aggressive and territorial.

How Many Cardinal Fish Should Be Kept Together?

knowing that these are very aggressive fish, you might be wondering if they could live together at all and how many should be kept together.

How many Cardinal fish should be kept together? The recommended number of Cardinal fish to keep together is two.

As I explained above, these fish are very fond of pairing in two and they could hardly tolerate the third fish.

The implication of keeping more than two in a tank is that the two that have paired themselves will stress and kill the third fish and even when they are kept in large numbers, they will still fight among themselves over territory and food.

So, if you ask me, I will tell you to have only two and it will be enough for you and maybe with other fish because they don’t show much aggression toward other fish.

Can I Mix Cardinal Fish?

Yes, different species of Cardinal fish could be kept together with little or no issue.

Although they are aggressive in nature, but they seem to be more of it to their kind and not much of it to other fish.

Again, before thinking of keeping different species of these fish together, you must have a large tank, let’s say up to 120gallons and above, depending on how many you are planning to keep so that they will have their territories, and eat.

Also put in place these different requirements such as caves, live plants, substrates, etc.


Cardinal fish are aggressive and territorial, so one keeps more than two of the same specie together to avoid aggression and death.