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Are Killifish Aggressive? (Aggressiveness By Species)

Are Killifish Aggressive? (Aggressiveness By Species)

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This post is written to the author's best knowledge and is not intended to be used in place of veterinary advice. In addition, this post may contain affiliate links. As an Amazon Associate I earn from qualifying purchases.

If you’ve recently seen some killifish at an aquarium store, you’ve likely become quite taken with them. There are many pretty types of killifish out there that you can buy.

Perhaps you’re thinking of getting some for your aquarium soon. Before you purchase these fish, learning more about them will help you to have a smoother experience.

For instance, you should learn about whether these fish are aggressive or not. Since there are different types of killifish, do aggression levels differ substantially based on the species?

Keep reading to learn all that you need to know about killifish aggression. This should make it easier to have a good time caring for these fish since you can set up the tank properly.

Killifish Can Be Aggressive

It’s true that killifish can be aggressive. Many types of killifish are considered to be semi-aggressive fish.

They’re carnivorous, and that means that they will eat other fish. However, they can only eat fish that are small enough to fit in their mouths.

If you know much about killifish, you know that they aren’t incredibly large. Some killifish are pretty small, and others are a bit larger.

You can’t keep killifish in a community tank with fish that they can eat. These fish can be fine in community tanks, but you must pick compatible tank mates.

It’s also important to know that killifish will sometimes be aggressive toward each other. Male killifish will fight with each other over mates and territory.

Most people choose to keep one male killifish and two female killifish in the same tank. This is the common setup that is known to produce good results.

Are Clown Killifish Aggressive?

Clown killifish aren’t very aggressive. Most would say that clown killifish are peaceful fish that are mostly passive in community fish tanks.

However, they can be a bit aggressive in some situations. You should also know that clown killifish are known to be fin nippers.

As always, you need to make sure that you choose appropriate tank mates for these fish. So long as you keep these fish in small groups and don’t put them in with the wrong types of fish, it’ll be easy to have a good experience.

Clown killifish are among the most popular types of killifish that you can find. If you’re thinking of getting some of these fish, you can expect to have a good time caring for them.

Are Golden Wonder Killifish Aggressive?

These killifish are some of the more peaceful that you can find. Golden wonder killifish are among the most common types that you can find in pet stores, too.

They’re very popular because they’re incredibly pretty, and they’re easy to take care of. Keeping golden wonder killifish in a community tank won’t be hard.

You can keep golden wonder killifish with most types of cory catfish. Otocinculus and banjo catfish can work out nicely, too.

Rams and dwarf cichlids are good tank mates for them. Even larger types of tetras can work out.

Are Magnificus Killifish Aggressive?

Magnificus killifish are truly stunning to look at. They’re well-known for having nice fins that have gorgeous patterns.

Luckily, these pretty fish are considered to be fairly peaceful. They get along well with other fish in community tanks, but you do need to keep them with fish that are around the same size.

So long as you research compatibility, it’ll be simple to keep these fish in a community aquarium. Like most killifish, the males will be aggressive toward each other.

Are Golden Lyretail Killifish Aggressive?

Golden lyretail killifish have orange bodies. These fish stand out because they have anal fins that feature a thick black band and a trailing edge.

You’ll be happy to hear that these fish are mostly peaceful. They’re actually a little bit shy, even in a fish tank setting.

These killies are known to hide a bit more often than many other popular killifish. Be sure to pick appropriate tank mates for them if you plan to put them in a community aquarium.

Are Red-Striped Killifish Aggressive?

Red-striped killifish are very colorful. When you want to add some color to your fish tank, these will be some of the best options you’ll find.

They have red stripes and spots that make them look really neat. Red-striped killifish are a little bit aggressive, though.

You can still keep these fish in community tanks by researching compatible fish that can tolerate them, but they’re known to nip fins quite a bit. Many people say that it’s easier to keep these fish only with their own kind.

Are Blue Gularis Killifish Aggressive?

Blue gularis killifish are appealing because of how bright and colorful they are. They have red bodies that feature metallic blue stripes.

Their fins are especially beautiful. They have blue fins with really nice patterns.

These fish can indeed be aggressive. It’s said that blue gularis killifish have a wide range of different temperaments.

Are American Flagfish Aggressive?

American flagfish are popular and interesting types of killifish. They’re colorful, and they have a pattern that is kind of reminiscent of the American flag.

They’re a bit on the aggressive side, sadly. So you might not want to use these fish for your community tank.

These flagfish are known to stress other fish in the tank. They go around nipping at the fins of other fish, and it can be a real problem.

Are Norman’s Lampeye Killifish Aggressive?

Norman’s lampeye killifish are commonly found in pet stores. These are well-known killifish that have pretty and colorful bodies.

If you’re looking for fish that will add aesthetic appeal to the tank, these fish will work nicely. They’re not super aggressive either.

As usual, the males won’t get along with each other that well. If you keep one male with two or three females, everything should be fine.

Are Blackfin Pearlfish Aggressive?

Blackfin pearlfish are a type of killifish that many people love. They don’t live for long periods of time, but they look nice, and they’re easy to care for.

These fish should not be kept in community tanks. They’re far too aggressive to be kept with other types of fish.

You want to keep them in a separate tank with only their own species. Keep only one male in the tank, or there will be fighting issues.

Are Argentine Pearlfish Aggressive?

Argentine pearlfish are appealing in certain ways, but they’re very aggressive. Much like the blackfin pearlfish mentioned above, these fish are too aggressive for community tanks.

You can have a fairly easy time caring for them in their own tanks. It’s just not wise to try to put them in community tanks.

Are Redtail Notho Killifish Aggressive?

The redtail notho is a much better fish to buy when you want to have peace in the tank. These fish are generally peaceful and easy to put in community tanks.

You still need to pick compatible tank mates, but they work fine in community aquariums. They don’t live long lives, though, and you should only expect them to live for up to a year.

Are Blue Notho Killifish Aggressive?

Blue notho killifish aren’t aggressive. They’re known to be peaceful fish that get along well with other fish that are the same size.

Much like with the redtail notho, it’s good to keep these fish with others that are around the same size. You should have a good experience when putting these fish in your community aquarium.

Always Do Your Research

Before you put together a community aquarium, it’s best to research things thoroughly. You’ve learned about many of the popular types of killifish now.

There are many killifish that are fairly peaceful. Some might get a little aggressive, but others are going to be a bit shy.

Many types of killifish are fine for community tanks. Others should only be kept in tanks with their own species.

Research whatever type of killifish you want to buy. Ensure that they can be kept in community fish tanks before proceeding.

You also need to take the time to learn about compatible tank mates. Each species that can be kept in a community tank will have fish that they’re compatible with.

Never put fish in the tank with the killifish before researching compatibility. If you just put fish together randomly, it’ll likely lead to you having problems.

Remember that killifish can get bullied by more aggressive fish. They can suffer if you make poor choices.

Final Thoughts

Now you know that most killifish are a little bit aggressive. Males will often fight each other, and that’s why it’s best to keep only one male in the tank.

One male killifish being kept with two or three female killifish will work out fine. Many killifish are peaceful enough that they will make good community fish.

Some are too aggressive to be kept in community aquariums, though. Remember to look things up first so you don’t make mistakes.

You should have a good experience caring for these fish. Enjoy your killifish, and be sure to learn about the types that you’re interested in before making any decisions.

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