11 Aggressive Freshwater Fish for Predator Tanks – Species Guide

We often choose beautiful, peaceful, freshwater community fish for our home aquariums. They’re generally easier to care for and we can enjoy the calming experience of watching our fish swim serenely along in their tank.

But not all aquarists want a peaceful community aquarium – and here’s why. Aggressive freshwater fish provide a level of stimulation that the peacekeepers don’t provide.

Not only are they more interesting and dynamic in the way they interact with each other but they are also more likely to be able to form a bond with you, their owner – and who doesn’t want their own pet to bond with them?

Let’s take a look at out Aggressive Freshwater Fish Guide for Predator Tanks so if this idea appeals to you, you’ll know where to start!

11 Aggressive Freshwater Fish

While there are many different species of aggressive freshwater fish that you can keep at home, here are a few of our favorites:

1. Jewel Cichlid

Jewel Cichlid

Have you ever seen a Jewel Cichlid? If you have, you probably haven’t forgotten its beautiful colors!

The Jewel Cichlid is considered a show-stopping fish and is usually the main attraction in its tank.

The Jewel Cichlid is native to Africa and ranges anywhere from three to 12 inches in length. While this seems like quite the range, keep in mind that a fish’s environment heavily contributes to its size and the Jewel Cichlid is on the larger end of this range in the wild only.

They are known for their bright colors which become even more prominent during breeding.

In terms of aggression, the Jewel Cichlid is quite territorial so it’s a good idea to make sure that this fish has both plenty of room and enough objects for it to establish its territory.

With the right setup, you shouldn’t have too much trouble with this fish regarding its ability to get along with others.

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  • Length: 3 to 12 inches
  • Water temperature: 74°F – 80°F
  • Care level: Beginner-Intermediate
  • Temperament: Aggressive
  • Diet: Omnivorous
  • Tank Size: 40-100 gallons*

2. Flowerhorn

The Flowerhorn

The Flowerhorn is actually a Cichlid and one of the most sought-after Cichlids out there for aquarists.

The Flowerhorn is a hybrid of many different South African Cichlids and is a man-made species – in this case, this means that they were bred by Chinese fishkeeping enthusiasts and no such fish is found naturally in the wild.

The Flowerhorn has only been around since 1996 and is incredibly popular due to its unique appearance and range of bright colors.

You often see the Flowerhorn as a fiery red or golden color. Arguably their most defining feature is their bulged head that gives the appearance of a very large brain protruding out of the top of their head and their deeply set eyes.

A fun fact about the Flowerhorn (and part of their appeal to their owners) is that they like being a pet.

This is one of the only fish that like to be touched by humans and appears quite affectionate with their owner.

That said, they will only act affectionate toward the person that feeds them and are aggressive with everyone else – including other fish.

While some Flowerhorns can be housed with other large Cichlids and Catfish, others do not get along with other fish at all.

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  • Length: Up to 12 inches
  • Water temperature: 80°F – 85°F
  • Care level: Intermediate
  • Temperament: Moderate to aggressive
  • Diet: Omnivorous
  • Tank Size: 75 gallons or larger

3. Wolf Cichlid

Wolf Cichlid

If you want an aggressive fish, you don’t have to look any farther than the Wolf Cichlid!

The Wolf Cichlid, otherwise known as the Dovii Cichlid, is an aesthetically appealing known for its hyper-aggressive nature.

So keep in mind there will be very few fish that can be housed for any sort of period of time with the Wolf Cichlid.

The Wolf Cichlid is highly intelligent and is very easy to keep, even for beginner aquarists. It’s best to give your Wolf Cichlid lots of rocks, caves, and deep sand beds.

They are large and aggressive fish but they are easily scared and need somewhere to hide and feel secure.
These fish also require lots of open swimming space and benefit from an exceptionally large tank or pond. This is also because they can reach over two feet in size!

The Wolf Cichlid is highly territorial of its space which is a primary reason why it cannot be housed with other fish.

You will find that they are highly interested with what is going on even outside of the tank and may start considering some of your own living room as part of their territory.

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  • Length: Up to 28 inches
  • Water temperature: 72°F – 81°F
  • Care level: Expert
  • Temperament: Highly aggressive
  • Diet: Carnivorous
  • Tank Size: 180 gallons or larger

4. Black Wolffish

Black Wolffish

If Cichlids aren’t your thing, we have another highly aggressive predator fish originating in the Amazon – the Black Wolffish.

The Black Wolffish is part of the Erythrinidae family and looks distinctly like a predator. It has an impressive array of teeth consisting of large canines and heavy molars, giving it its distinctive menacing look.

An interesting fact about the Black Wolffish is that their color changes according to their mood and varies from a light brown to nearly solid black.

Their bodies are relatively bulky and broad with a blunt head. The Black Wolffish won’t get any bigger than a foot and can be kept in community tanks, despite their highly aggressive nature.

The black Wolffish is rare and expensive so this is not a fish that can be purchased on a whim – it requires research and serious thought about whether you have the means to care for this fish.

Even though the Black Wolffish is menacing, it can be kept with certain other species given enough space and the right environment. These may include Cichlids and even Silver Dollars.

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  • Length: 16 to 20 inches
  • Water temperature: 76°F – 82°F
  • Care level: Expert
  • Temperament: Highly aggressive
  • Diet: Carnivorous
  • Tank Size: 120 gallons or larger

5. Jaguar Cichlid

Jaguar Cichlid

A companion for the experienced fish keeper, the Jaguar Cichlid is a beautiful fish that gets its name from – you guessed it – its jaguar-like patterning. Unlike most Cichlids, the Jaguar Cichlid does not develop its permanent black patterning until it matures.

In fact, when they’re young, both male and female Cichlid have several dark bars across their bodies. When male Jaguar Cichlids mature, they lose these bars altogether and develop jaguar-like patterning.

Females do not necessarily lose their black bars but they do develop black spots on top of it.

Another interesting fact about Jaguar Cichlids is that they can become large enough to warrant human consumption, which is uncommon for aquarium fish.

In Central America, they are used for food but can also be considered pests.

The Jaguar Cichlid is relatively easy to care for, as long as you have a suitable tank and tankmates that they are less likely to eat.

They are semi-aggressive and like to prey on smaller fish. If you’re looking for tankmates, try other large semi-aggressive Cichlids but be warned that they may not tolerate any other fish in their tanks, unless they are a male/female pair of the same species.

Even then, the Jaguar Cichlid may attack or kill a newly introduced female. 

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  • Length: 21 to 24 inches
  • Water temperature: 75°F – 79°F
  • Care level: Easy to moderate
  • Temperament: Aggressive
  • Diet: Omnivorous
  • Tank Size: 100 gallons or larger

6. Red Devil Cichlid

Red Devil Cichlid

Looking for an aggressive Cichlid with an equally aggressive-sounding name? You don’t need to look much farther than the Red Devil Cichlid!

As you may have guessed, this Cichlid was named for its aggressive nature, large teeth, and strong jaws and are one of the most aggressive Cichlid’s out there.

This fish should not be kept with other fish at all, except when they’re young but. That said, many aquarists do successfully keep the Red Devil Cichlid with other fish in a large aquarium with numerous caves and hiding spots.

As long as the Red Devil establishes a territory and other fish do not try to bother it, you may be able to successfully keep them together.

The Red Devil Cichlid ranges in color and is often completely yellow. They may also appear pale white and orange with some red coloration.

They are robust and stocky with pointed anal and dorsal fins. It takes about three years for the Red Devil to reach its full size but a large Central American Cichlid can reach about 15 inches.

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  • Length: Up to 15 inches
  • Water temperature: 70°F – 79°F
  • Care level: Easy to moderate
  • Temperament: Highly aggressive
  • Diet: Carnivorous
  • Tank Size: 55 gallons or larger

7. Oscar Fish

Oscar Fish

You’ve likely seen the Oscar fish in a pet store as it’s one of the most common aggressive and territorial fish you will come across.

The Oscar is also a Cichlid and comes in a variety of beautiful colors, making them quite an attractive fish.

While the Oscar Fish may look like it has a bad attitude, this is only half true. The Oscar Fish is usually considered an aggressive fish but it is really only semi-aggressive.

This means that it will likely be easier to keep than a lot f other territorial fish. These Cichlids are also famous for bonding with their owner and can be seen eating from their owner’s hand or wanting to be petted.

If you’re looking for other fish to house your Oscars with, you may have luck with other large fish, particularly if they like to school.

These include large Catfish, Bichirs, Silver Dollars and other Cichlids.

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  • Length: Up to 14 inches
  • Water temperature: 74°F – 81°F
  • Care level: Easy to moderate
  • Temperament: Territorial/aggressive
  • Diet: Omnivorous
  • Tank Size: 40 gallons or larger

8. Green Texas Cichlid

Green Texas Cichlid

The Green Texas Cichlid is a beautiful and iridescent fish often known as the Pearl Cichlid.

They are pearl-gray in color with blue to green-hued scales with iridescent sparkling extending all the way to the fins.

An interesting fact about the Green Texas Cichlid is that they are the northernmost naturally occurring Cichlid species in the world being native to south Texas and northern Mexico.

The Green Texas Cichlid loves to interact with its owner and is an intelligent and entertaining fish. That said, you will likely not be able to house them with other fish due to their aggressive nature.

You can try housing them with other Cichlids that have an equal or higher aggression level to avoid your Green Texas Cichlid killing fish that cannot fend for themselves.

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  • Length: Up to 12 inches
  • Water temperature: 68°F – 75°F
  • Care level: Easy to moderate
  • Temperament: Aggressive
  • Diet: Carnivorous
  • Tank Size: 55 gallons or larger

9. Hoplias Aimara

Hoplias Aimara

This fish is actually commonly known as the Black Wolffish but they are not the same fish that we have already listed, though they are a close relative of the Black Wolf fish and part of the same family (the Erythrinidae).

That said, there are a few differences. Although both fish are rare, the Aimara is exceptionally more so and costs upwards of thousands of dollars.

It is not advisable to keep the Aimara with any tankmates at all.

First, only aggressive fish would stand a chance against the Aimara. And second, you’re risking a fish you’ve spent possibly thousands of dollars on being attacked or killed because you wanted to try to keep it in a tank with other fish.

No, thank you.

Looking for a predator fish that is still sweet and interactive with its owner? Then the Aimara is not for you.

Not only is the Aimara aggressive towards other fish but they’re not fond of their owners either.

This fish should really only be kept by people who enjoy watching predator fish up close and understand that they are in no way going to be a typical pet.

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  • Length: Up to 39 inches
  • Water temperature: 72°F – 77°F
  • Care level: Advanced
  • Temperament: Aggressive
  • Diet: Carnivorous
  • Tank Size: 300 gallons or larger

10. Mini Dovii

The Mini Dovii

The Mini Dovii, otherwise known as the Sieve Cichlid, is not closely related to the Wolf Cichlid or the Dovii Cichlid – in fact, one of the only things that they really have in common is their similar appearance but the Mini Dovii is about half the size.

Both Cichlids are known for their aggressive natures but have at times been successfully kept together in the same tank.

Unlike the Wolf Cichlid, the Dovii Cichlid has been successfully kept in the same tank with multiple different kinds of semi-aggressive species and sometimes their own kind.

If you’re looking to add the Mini Dovii to a community predator tank, it can usually be paired with catfish, plecos, and other large cichlids.

Although this species is quite aggressive, it is most often evident when breeding. If there are no other Dovii Cichlids in the tank, it will be more compatible with the community as there will be no fish of its own kind to trigger that breeding behavior.

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  • Length: 8-10 inches
  • Water temperature: 72°F – 81°F
  • Care level: Intermediate
  • Temperament: Aggressive
  • Diet: Carnivorous
  • Tank Size: 75 gallons or larger

11. Umbee Cichlid

Umbee Cichlid

The Umbee Cichlid is a large, highly aggressive, beautiful fish that is affectionately known as the blue freckled monster.

If you’re looking for an aggressive fish with tons of personality and desire to interact with its owner then the Umbee Cichlid could be exactly what you’re looking for.

The Umbee Cichlid is highly intelligent and shows a great deal of interest in what is going on outside of its tank, similar to the Dovii Cichlid.

In fact, these two are rivals for owners who want this particular type of aggressive Cichlid. They have a lot of similarities in personality, coloration, and aggression. As with any aggressive species, keeping the Umbee Cichlid with tankmates is not a good idea.

The Umbee should be the largest fish in the tank but can be kept with large Sailfin Plecos and Catfish (but again, only if the Catfish are smaller than them).

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  • Length: Up to 24 inches
  • Water temperature: 72°F – 80°F
  • Care level: Advanced
  • Temperament: Aggressive
  • Diet: Carnivorous
  • Tank Size: 240 gallons or larger

Conclusion

Any of the 11 aggressive freshwater fish on this list would be a fantastic addition to any at-home predator tank.

Just remember that keeping a predator fish or setting up a predator tank is not to be done on a whim.

It is incredibly important to do your research and speak to an expert before taking on one of these fish and even more so before deciding to try to combine them with other fish a community tank.

Not only do you have the welfare of your fish to watch out for but do you really want to spend $800 on a fish only for that money to go immediately down the drain due to another aggressive fish’s attack? We think not.

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