Will Oscar Fish Eat Other Fish? (Best Tank Mates For Oscar Fish)

If you want to keep Oscar Fish in your existing fish tank, but wondering, will the Oscar Fish eat other fish in your tank then you are in the right place.

Because in this article, I am going to answer the same question.

So will oscar fish eat other fish?

The short answer is- Yes, Oscar Fish will eat other fish that are small enough to fit into its mouth.

Oscar Fish is a predator and in the wild, it feeds on small fishes, small insects, crustaceans as well as plant matters.

Will Oscar Fish Eat Other Fish? (Best Tank Mates For Oscar Fish) image

What fish can an Oscar Fish eat?

Though Oscar Fish are omnivorous their diet mostly consists of meaty foods.

As mentioned earlier, in the wild, Oscar Fish feeds on crustaceans, small insects, small fishes as well as plant matter.

So, in your aquarium, your Oscar Fish will eat anything that can fit it into its mouth i.e. it will eat any fish that can fit into its mouth.

If you got a Juvenile or baby Oscar Fish then you can keep it with other small species of fish like Guppies, Zebra danio, Neon tetra, etc.

But as Oscar fish grows bigger, you will have to move the other small fish or your Oscar to a separate tank. Or else they will most likely get eaten by the Oscar.

Oscar Fish grows very fast. It can grow at a rate of 1 inch per month. And generally, it grows up to 12 inches but if you take good care of it then it can grow up to 15 inches as well.

Some people say that if you keep other small species of fish with baby Oscar Fish and as they grow together the Oscar Fish will not eat them. 

Now, it can happen sometimes but it is not the case most of the time.

Oscar Fish have very unique behavior and every Oscar is different than other Oscar.

So it is not guaranteed that if the fish grow together in the same tank from a very small age then the Oscar Fish will not eat them.

At the end of the day, Oscar Fish is a Predator fish and other small species of fish are just food for it.

Overall, Oscar Fish can eat any fish that fits into its mouth.

Are Oscar Fish Good Pets?

What fish Oscar Fish cannot eat?

Oscar Fish cannot eat the fish that a large enough to not fit into its mouth like Silver Arowana, Convict cichlids, Pleco, etc.

Can you keep other species of fish with Oscar Fish?

You can keep other species of fish with Oscar Fish.

But there are a few things you should keep in mind while choosing fish to keep with your Oscar Fish.

  • First of all, you should only consider the fish that require similar water conditions that your Oscar Fish require so they can both thrive in the tank.
  • You should choose the fish that are larger than the size of the mouth of your Oscar Fish. Because if you choose small species of fish then it is most likely going to get eaten by your Oscar.
  • Besides, you should choose the fish that are semi-aggressive and can hold their own against Oscar Fish.

Can Oscar Fish Live Alone? (Yes, but…)

What are the best tank mates for Oscar fish?

Though Oscar Fish is very aggressive there are some good tank mates you can keep in your Oscar fish tank.

Usually, other cichlids that are similar to the size of your Oscar Fish are very good tank mates for Oscar Fish.

Also, there are some other species of fish you can keep with your Oscar Fish.

Firemouth Cichlid

Firemouth Cichlid
PARAMETERSVALUES
FISHFiremouth Cichlid
SCIENTIFIC NAMEThorichthys meeki
FAMILYCichlidae
CARE LEVELEasy
MAXIMUM SIZE7 inches
AVERAGE LIFESPAN15 years
DIETOmnivorous
WATER TEMPERATURE75-86°F
WATER pH6.5-8.0
WATER HARDNESS8-15 dGH
BREEDINGLive bearers
MINIMUM TANK CAPACITY30 gallons

Firemouth cichlid belongs to cichlids family so they are naturally aggressive fish and can hold their own against Oscar Fish.

This fish can grow up to 7 inches so it will not fit into the mouth of your Oscar Fish and get eaten.

Besides, Firemouth cichlid is very hardy and easy to care for.

Tank

The minimum tank requirement for Firemouth cichlid is at least 30 gallons.

The ideal temperature for Firemouth cichlid is between 75-86° Fahrenheit, the pH tolerance is between 6 to 8, and hardness tolerance ranges between 8 to 15 dGH.

So the ideal water parameters of Firemouth cichlids are similar to that of Oscar Fish, so you can easily keep them both together.

Can Oscar Fish Live In Cold Water?

Food

Just like Oscar Fish, Firemouth cichlid is omnivorous and but its diet mostly consists of meaty foods.

So they can eat almost everything that you can feed to your Oscar Fish and they don’t require any special food.

On a daily basis, you should feed them high-quality cichlids flakes and pellets. Because it has all the nutrients that the fish requires for its proper growth and development.

Besides, you can also treat Firemouth cichlids with frozen or live foods such as bloodworms,  brine shrimp, etc.

As Firemouth cichlids are omnivorous, along with meaty foods they also need veggies.

You can feed vegetables such as spinach, carrot, boiled peas, lettuce, etc to Firemouth cichlid.

Before feeding these veggies, is just make sure to boil them and cut them down into small pieces so that it will be easy for them to consume.

Overall, Firemouth cichlid is large enough to not fit into the mouth of your Oscar Fish and it can also hold its own against Oscar Fish.

Besides, they are very hardy and easy to care for and they eat the same food that your Oscar fish eats.

Also, the ideal water parameters that Firemouth cichlid require are similar to that of Oscar Fish which makes them a very good tank mate to keep in your Oscar fish tank.

How Long Can Oscar Fish Go Without Eating?

Just like fire mouth cichlids there are are several other cichlids that you can easily keep with your Oscar Fish.

Following cichlids are very good tank mates for your Oscar Fish:

  • Convict cichlids
  • Jaguar cichlid
  • Green terror
  • Jack Dempsey
  • Severum cichlid
  • Blue acara

I have written a detailed article about all these cichlids and why they are good tank mates for your Oscar Fish here.

Besides cichlids, there are some other species of fish that you can easily keep with your Oscar Fish.

13 Types of Oscar Fish For Aquarium (With Images)

Bichir

Bichir

Image by Stan Shebs under CC BY-SA 2.5

PARAMETERSVALUES
FISHBichirs
SCIENTIFIC NAMEBichir
FAMILYPolypteridae
CARE LEVELIntermediate
MAXIMUM SIZE30 inches
AVERAGE LIFESPAN15-20 Years
DIETCarnivore
WATER TEMPERATURE77-84° F
WATER pH5-7.5
WATER HARDNESS8 - 12 dGH
BREEDINGEgg layers
MINIMUM TANK CAPACITY90 Gallons

Bichir is a unique looking bottom-dweller fish you can keep in your Oscar fish tank.

As this fish is a bottom dweller, it spends most of its time near the bottom or near the substrate of the tank so it will not bother you Oscar fish as Oscar fish rarely come to the substrate of the tank.

Besides, Bichirs are nocturnal fish, which basically means that they stay active during the night.

And hides behind ornaments in the tank, that could be driftwood, rock, plants, etc during the day.

So, it will not bother your Oscar Fish when it is active during the day.

Bichir also grows pretty large. It can grow as large as 30 inches.

And this is the reason it requires a very large tank of at least 90 gallons.

Bichir is also moderately aggressive fish so even when your Oscar fish tries to bully Bichir, it can hold its own.

Besides, the ideal water parameters that Bichir requires are similar to that of Oscar Fish so they can easily live together in the same tank.

Can You Put Live Plants with Oscars? (Best Plants for Oscars)

Silver dollar

Silver Dollar

Image by Haplochromis under CC BY 2.0

PARAMETERSVALUES
FISHSilver Dollar
FAMILYCharacidae
CARE LEVELIntermediate
MAXIMUM SIZE6 inches
AVERAGE LIFESPAN10 years
DIETOmnivores
WATER TEMPERATURE75-82°F
WATER pH5.5-7.5
WATER HARDNESS4-18 dGH
BREEDINGEgg layers
MINIMUM TANK CAPACITY75 gallons

Silver Dollar is one of the most popular schooling fish in the aquarium hobby.

This fish got its name due to its unique look. It looks similar to the old silver dollar.

This fish is herbivorous and you can feed it vegetarian flakes as well as vegetables such as cucumber, carrot, spinach, chickweed, etc.

Silver Dollar can grow as large as 6 inches so it will not fit into the mouth of your Oscar Fish and get eaten.

As Silver Doller is a schooling fish, you should keep it in a group of at least 5.

And the minimum tank requirement for five Silver Dollars is 75 gallons.

Keeping Silver Dollars in a group is very important when keeping it in an Oscar fish tank.

Because then your Oscar Fish will not target only one Silver Dollar and kell it.

The ideal water parameters that a Silver Dollar requires are quite similar to that of Oscar Fish so you can easily keep them together in the same tank.

Besides, if you are keeping only one Oscar Fish in the tank then keeping schooling fish like Silver Dollar is a very good way to keep your Oscar Fish entertained.

Other fish you can keep with your Oscar Fish

  • Silver Arowana
  • Pleco
  • Black-banded leporinus

You can read my detailed article about best tank mates for Oscar Fish here.

oscar fish tank mates infographic

FAQ

How many Oscar Fish can stay together?

You can keep as many Oscar Fish you want together.

But you just have to keep in mind a few things:

  • You should provide them sufficient space to swim around. Or else, every time, they will be on the face of each other and that can lead to fighting.
  • You should maintain ideal water parameters and feed them with high-quality fish food. If you don’t maintain the ideal water conditions then it will stress out the fish Oscar Fish and this can lead to aggression.
  • Also, if you don’t provide them sufficient food then they will compete for food with each other and this can also lead to aggression.

Can Oscar Fish eat Goldfish?

Oscar Fish is a Predator fish and it will eat any fish that can fit into its mouth.

So, if the Goldfish can fit into the mouth of Oscar Fish when it is most likely going to get it eaten by the Oscar Fish.

Are Oscar Fish Jumpers? (Can they jump out of the tank?)

What can you feed to Oscar Fish?

As mentioned earlier, Oscar Fish omnivorous but its diet mostly consists of meaty foods.

Primarily you should feed it high-quality cichlids flakes and pellets because it contains all the essential nutrients that your Oscar Fish require.

Besides, you can also treat your Oscar with frozen or live food such as bloodworms, brine shrimp, definition, feeder fish, etc.

As Oscar Fish is omnivorous, occasionally, you should also feed it vegetables such as spinach, boiled peas, carrots, lettuce, etc..

You can also read my detailed guide about Oscar Fish food here.

Conclusion

So if you are planning to keep Oscar Fish with other fish then make sure that they are not small enough to fit into the mouth of the Oscar Fish.

Because Oscar Fish will eat any fish that can fit into its mouth.

I hope you found this article helpful.

If you do, please share it.

As always, happy fishkeeping!

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Author
Prathmesh Gawai
He is the main author and editor at Aquagoodness.com. And he loves to share helpful information on aquarium and/or fishkeeping hobby. Prathmesh has over five years of aquarium and/or fishkeeping experience. Currently, he has a Betta fish tank. He has written hundreds of articles on various aquarium fish species and on fish tank maintenance over the last five years. Connect with him on YouTube here. Learn more about him here.

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