Everything About Oscar Fish You Should Know

If you are aquarists, then you must be familiar with the oscar fish. Some fish are very aggressive in nature, due to which they are very tough to manage. To manage such aggressive fishes, you need to be an experienced aquarist. Today, we will only focus on freshwater oscar fish. It is so far one of the toughest fish to care for. But once you get to know how to manage them properly, you can keep them with other fishes. In today’s post, I have gathered all the information related to this tiny creature. Let us now explore more about oscar fish in detail.

You can keep on reading further to know more about Albino oscar fish.


These fish species were originated from the Amazon and Orinoco river basins. Most individuals love to keep them as a captive-bred in their aquarium. You can easily find them in South American markets as a food fish. They are also have been introduced to Asia, Australia, and North America. In several US states, white oscar fish is labeled as non-native pest species.


Another common name for oscar is Tiger Oscar fish. They are darker brown to light green fish with highlights of red and orange. You can also see various color patterns along with a characteristic eyespot or ocelli on their tail fin. There are also some albino variations which are white in color with red spots. 

Click here – How Long Do Spiders Live?

You can also check out the pictures of oscar fish that are attached below.

Oscar Fish Size

Oscar Fish Size

Oscars(fish)  grow up very fast! After researching, it is found that they can grow at a rate of 1 inch per month till they reach adulthood. So, the average size of an oscar can be between 10 to 12 inches in length. When they are young babies, they are 1 to 2 inches just like other fishes. But if they are kept under the right conditions, they can grow quickly. Make sure you purchase an ideal oscar fish tank for your pet fish!


This fish species usually live for a very long time if you take proper care of them. The ideal oscar fish lifespan is of up to 20 years. They can also live between 10 to 20 years if you maintain good quality water in your aquarium.

Gender And Breeding

There are both male and female Oscars. But it is often difficult to spot the difference between male and female Oscars. To check their gender, you have to flip them upside down and examine them. Mostly female Oscars have one large hole to lag their eggs. Whereas male Oscars also have one hole but it is smaller compared to the female ones.

Oscars are very picky when it comes to selecting a female oscar for breeding. You can place your Oscars into a separate 100 gallons tank for breeding. Make sure the water is warmer than usual about 26 to 30 degrees celsius. Female Oscars will lay their eggs which the male oscar will then swim over to fertilize them. These eggs should be kept in the breeding tank till they are matured.

Diet And Feeding

Now, here comes the most important section that is oscar fish food! We know that Oscars are carnivorous who often prey on small fishes present in their tanks. So, it is best to avoid putting too many tank mates in their tanks. Their diet consists of the following food items.

  • Pelleted cichlid diet
  • Meaty supplements
  • Bloodworms
  • Tubifex Worms
  • Frozen krill
  • Brine Shrimp
  • Flakes
  • Wafers
  • Frozen peas
  • And other larger frozen diets

You can also feed them live foods. But I think you should avoid this as it can spread disease into your tank and can overpopulate your tank.

Tank Mates

Individuals need to be very careful while choosing the tank mates for oscar. As I have mentioned earlier, they are very aggressive in nature. So, they might eat their tank mates. Make sure you choose oscar fish tank mates that belong to the same region. You can go for South American fish species that are listed down below.

  • Jack Dempseys
  • Convict Cichlids
  • Silver Dollars
  • Arowanas
  • Large Plecos

These fishes are of similar size just like oscar.

Oscar Fish Care

As these cute little creatures grow up very fast, you need to purchase a huge tank for them. So, make sure that an oscar fish tank size should not be smaller than 55 gallons! This will help them to swim stress-free with their tank mates. 

Oscar (fish) require more maintenance than other fishes as they are very messy. You need to frequently change the tank water as they produce a lot of waste. They are very sensitive to water temperature. So, it is preferred to use water with a pH balance of between 6 to 8 with 23 to 27 degrees Celsius temperature. You can also set up a water filtration system, aquarium heater, and built-in thermometer in your tank. 

If your oscar (fish) follow a healthy diet, then they are less likely to get sick. But if you do not take proper care of them, they can suffer from a hole in the head disease. This disease usually occurs when your fish is stressed.

Interesting Facts Of Oscar Fish

Here, I have listed down some common facts of baby oscar fish in detail.

Common Name Oscar, Tiger Oscar, Marble Cichlid, Velvet Cichlid
Scientific Name Astronotus ocellatus
Origin South America
Water Type Freshwater
Length  10-14 inches
Lifespan 10 to 20 years
Diet Carnivorous
Optimum Temperature 75 to 80 degrees Fahrenheit 
Optimum pH level In between 6 to 8


Are Oscars Aggressive Fish?

Yes, Oscars are very aggressive fish. Individuals must avoid keeping other small fishes in their tank or else they will prey on them. But they are also one of the most intelligent fish species found in the aquarium.

Do Oscars Eat Other Fish?

Yes, oscar do eat other fishes present in their tank. They usually prey on small fishes, small insects, and crustaceans. They also love eating plants such as java fern, Salvinia natans, and java moss.

What Size Tank Do I Need For 2 Oscars?

For one oscar, you need at least a 55-gallon tank. Therefore for 2 Oscars, you need at least a 75-gallon tank. These tiny creatures grow up to 12 inches in size. So, for every new addition of oscar, you require an extra 20 to 30 gallons tank.

How Many Oscar (Fish) Can Stay Together?

You can keep a minimum of two and a maximum of five Oscars in a single tank. They love living in pairs as well as groups so that they can bond with each other.

What Human Food Can Oscar Eat?

Oscars love to eat the following human foodstuffs.

  • Chopped cucumbers
  • Zucchini
  • Frozen peas
  • Shelled nuts
  • Tropical nuts
  • Fruits 

What Are The Different Types Of Oscar Fish?

Here, I have listed down the most beautiful oscar fish types.

  • Tiger Oscar
  • Red Oscar
  • Albino Oscar
  • Blue Oscar
  • Black Oscar
  • Florida Oscar
  • White Oscar
  • Green Oscar
  • Veil Tail Oscar
  • Lemon Oscar

Is Oscar Fish A Good Pet?

Oscar Fish are very good pets to keep in your tank and they can be the center point of your aquarium. Keeping Oscar Fish is not very easy so you should only consider keeping Oscar Fish if you have some experience in fish keeping. Also, it is very difficult to find good tank mates for your Oscar Fish.

What Size Tank Do I Need For 2 Oscars?

Tank Size and Requirements

Ideally, however, a 75-gallon tank is best for one adult Oscar and, if you plan to keep more than one, you will need a tank at least 100 gallons in capacity.

Do Oscar Fish Know Their Owners?

Oscars are intelligent fish that love to swim with purpose around the tank. They can recognize their owners and can be hand-fed. However, they have territorial tendencies, so you should carefully choose the fish you house along with it in a community tank to prevent stress among the fish.


There are so many fish species across the globe, oscar fish is one of them. These cute little fascinating creatures are very aggressive and notorious in nature. But they look extremely beautiful and are quite intelligent too. Oscar (fish) can live for a very long time if you take proper care of them. They are about 10 to 12 inches in length and have a lifespan of 10 to 20 years. They usually prey on small fishes, small insects, and crustaceans. If you are ready to keep them as your pet, then my above guide on oscar fish might be useful for you.

Click here – What Do Kangaroos Eat?

What do you need to know about Oscar fish

What is an Oscar fish?