Oscar Fish Care Guide, the Intelligent Aquarium Pet

The Oscar fish is a predatory fish native to the Amazon basin, and this fish species is from the cichlid family. The experts first discovered this species in 1831. You can find them also in India, China, and Australia. Oscar fish is trendy in the aquarium trade.

They are one of the most intelligent fish species. You can quickly train them to play tricks in the aquarium tank. I’ll talk about their characteristics and requirements to provide a complete Oscar fish care guide. 

They are playful, smart, and courageous. Oscar fish interact with humans, and that’s an incredible experience for aquarium keepers.

They will come near the aquarium glass to interact with you whenever you pass by their tank. You can hand feed them. Their mannerism is entertaining to watch. 

Oscar fish are famous for their intelligence and infamous for aggression. They are sluggish in movement but capable of ambushing prey over short distances.

Hence they are dangerous for smaller fish. Oscar fish can be a little tough choice for beginners, but they are amusing characters.

Basic Information About Oscar Fish & Care Requirements

Scientific Name Astronotus Ocellatus
Care Level Moderate
Temperament Terriotorial/Aggressive
Diet Omnivorous
Maximum Size 20 inches
Expected Lifespan 20 years
Ideal Tank Size (Minimum) 55-gallon
Compatibility Large passive fish
Water Temperature 77-82 degrees Fahrenheit
pH Level 6-8
Water Hardness 12-15 DH


Oscar fish have a wide variety of colorations. Numerous types of Oscar fish are available today in the aquarium trade. But naturally, there were only three kinds of them in the wild; the Tiger, Albino, & Red Oscar. All other types of them came from crossbreeding.

You can classify Oscars into various types based on their appearance. They can be red, orange, black, blue, white, green, and lemon with many different combinations and color patterns. They have a long, egg-shaped body with symmetrical caudal fins. Oscar fish have large aggressive-looking eyes.


Oscar fish tends to be territorial and aggressive, but that’s a one-sided story! At the same time, they are quite intelligent and social creatures. They are one of the few fish that you can train to do tricks.

They love to play and communicate with humans. However oscar fish have teeth, and they can also bite humans. The bite is not poisonous or can’t hurt you critically. But be careful, and if you raise oscar fish from their baby age they won’t bite.

Yet they can be ferocious when the deal is about food and mating! Due to their intolerant behavior, an inexperienced aquarist may face difficulties to handle Oscar fish. And they are not an ideal community fish to keep with others.

Unlike most other predatory carnivores, Oscar fish are very protective parents of their children. They defend their territories and protect their babies very carefully.

Brood-caring is a rare phenomenon among fish species, which signifies their intelligence.

Size and Life Span

The average size of Oscar fish in captivity is 12 inches, but they can grow up to 18 inches in the wild. In a sufficiently spacious aquarium, Oscar fish can grow as big as 16 inches. But they need a proper diet and stress-free life to attain that size.

Oscar fish has a relatively long lifespan, which is 15 years on average. But if it is possible to provide them an ideal condition and good care, you can expect them a few more years to survive. Oscar fish living 20 years in an aquarium is not unlikely. Having so long time with an intelligent species can create emotional bonding between the pet and the owner.

Some Popular Types of Oscar Fish

I will discuss three original and three crossbreeding species of Oscar Fish. These six are the most common types you will find in home aquariums. Other than the appearance, these species are very similar in their behavior and all other aspects.

Tiger Oscar Fish

Tiger Oscar Fish

They are aggressive and colorful! Aggression is part of their personality, which suits them nicely. They have black and orange coloration that is very attractive.

Tiger Oscar fish is the most popular aquarium fish among Oscars. The appearance of black and orange stripes resembles that of a tiger. A fully grown Tiger Oscar fish can grow up to 15 inches.

Albino Oscar Fish

Albino Oscars are very pretty looking. They are almost entirely white with orange and red lattice. The density and design of the orange pattern are not the same for all individuals. Variation in color makes them highly sought for aquarium keeping.

Red Oscar Fish

Red Oscar Fish

Some of them can be entirely red, while others may have a two-colored appearance dominated by red. Their fins can be black, and their eyes will have orange rims. The Red Oscar can grow as large as 16 inches.

Large aquariums above 60 gallons are suitable for them. A deep sand substrate with a few larger rocks can make them happy. They add more colors to your aquarium, no doubt!

Veil Tail Oscar Fish

The name suggests their specialty! They have long veil-like tails, which makes them unique, attractive, and delicate. Veil Tail Oscars have variations in colors. They can be white, a combination of black-orange, or reddish in appearance. Whatever the color is, they look beautiful with their trademark tails, and whenever they expand them, it becomes entertaining to watch.

Lemon Oscar Fish

Most of them have a bright lemon color that makes them distinguishable from all other species of Oscar. Some may not have an entirely lemon color appearance; instead, a lemon-green gradient on a white body. Proper nutrition and healthy water condition are favorable for flourishing their attractive body color.

Copper Oscar Fish

Copper Oscar Fish

This crossbreed species of Oscar Fish is famous for its beautiful appearance. Their head and back are black, but the rest of the body is bright orange or copper in color. The vibrant copper color of Oscar can make your aquarium scenery eye-catching.

Like all other species of Oscar, they can grow large, up to sixteen inches! Eight to twelve years is their expected lifespan in an activity. Pristine water conditions encourage their bright coloration.

Oscar Fish Care

Food and Diet

Oscar fish are carnivorous, and they love to feed on living foods, but the young ones tend to feed on flakes. They have a voracious appetite, and they want to eat everything that fits inside their mouth.

So they are not picky about the food, and it’s good news for the Oscar owners. Though Oscars are primarily meat-eaters, it’s not unusual for them to eat plants and vegetables.

In aquariums, you can feed them Cichlid-friendly prepared pellets and flakes. Bloodworms and brine shrimps are common foods that Oscar owners provide them. You can even feed them live insects like crickets and grasshoppers.

For additional supplementation, you can try with fruits and nuts, providing them chopped off into pieces.

Tank and Water Conditions

Suitable Tank and Water Conditions for Oscar

Oscar fish need large tanks to have an ideal habitat, and a 55-gallon tank is a minimum requirement for a single Oscar. You can keep more than one in an aquarium. In that case, the thumb rule is adding 25 gallons for every additional member. That means 80 gallons for two and 105 gallons for three Oscars.

They are not comfortable in a crowded place, and when they are uncomfortable, they become angry. When they are annoyed, they become furious.  

Deep sand substrate combined with a few large rocks can accent natural flavors for the Oscar fish. They show the tendency to dig up plants, so if you put them in a planted aquarium, make sure plants are deeply rooted.

Sometimes Oscars may try to jump out of the tank for searching foods (or adventures! Whatever! They know better.) Your job is to cover the tank with a lid.

Oscar fish are not too sensitive to water conditions and can adapt to variations. Like all other tropical fish, they prefer warmer water of 75-80°F. They are okay with the pH ranging from 6 to 8 and 12- 15 DH’s water hardness.

Oscar Fish Tankmates

Oscar Fish Tankmates

Oscar fish can live alone happily. However, maybe sometimes you may feel your oscar fish is not active or engaged. In that case, pairing with another oscar fish or introducing tank mates can improve the situation.

However, oscars are not compatible with most other fish species. They will prey on small fish and fight with larger active fish. Only large peaceful, passive fish can be their tankmates. So you have to be very careful and picky when choosing their tank mates. Keep in mind the following points. 

  • Do not put small fish in an Oscar tank. They try to eat whatever fit’s their mouth. 
  • Do not put timid and shy fish with Oscars. Your Oscar will harass shy fish by chasing them all the time.  
  • Do not put large, aggressive fish. Oscar will engage in a bloody fight. 
  • Put relatively larger passive fish that can move swiftly. They can compete for food but don’t fight. 
  • Bottom-dweller fish are compatible with Oscars as they remain out of their sight most of the time. 

I am keeping Blood Parrot Cichlids, Gouramies, and bottom-dweller Catfish with Oscars. They are living happily so far.  

Oscar Fish Diseases and Cure

Early diagnosing of aquarium fish diseases is crucial for their recovery, and Oscar fish is no exception. You’ll have to their disease symptoms. Here I’ll discuss three infections of Oscars.

Hole In The Head (HITH)

Oscars are hardy fish and don’t easily get infected with any disease. But there is one particular disease that you should be careful about. ‘The hole in the head’ is that disease, and it can be dangerous for your Oscar if not treated with early symptoms.

At the primary stage of this infection, one or two holes appear on the fish’s head and can get worse day by day. If you observe any symptoms, you should immediately start medication and change the aquarium water.

Metronidazole is a common medication for hole-in-the-head, but it is better to seek an expert vet’s prescription.

The disease is preventable by maintaining healthy water conditions. For the better health of Oscar fish, you should provide vitamin and nutrient-rich food. A clean aquarium environment and a proper diet are the keys to preventing all sorts of infections.

Ich (Ichthyophthirius multifiliis)

Ich is a common aquarium fish disease. A parasite called Ichthyophthirius multifiliis (ich in short) causes this disease. However, white spots appear on the fish’s body (it looks like salt is sprinkled) by this infection.

If not treated by the early symptom, ich can be life-threatening. Especially when grills and mouths are infected by ich, it becomes dangerous.

For treating ich in Oscars, the best medicine is a combination of malachite green and formalin. You’ll get drugs like Ich-X available in the market. Some aquarists add salt as the remedy of ich. Rising the water temperature is also helpful in treating ich.

Fin and Tail Rot

Fin and Tail Rot is a Columnaris disease of Oscar fish. Unhygienic water conditions lead to this infection. Blackened, bloody, or tattered fins are its symptoms, and you will observe Oscars staying near the surface most of the time.

Maintaining a tidy aquarium condition is the best way to prevent fin & tail rot. Whereas antibiotics like Oxytetracycline, Tetracycline, and Chloramphenicol are useful medications for this infection.

Final Words

Having Oscar fish as aquatic pets will be entertaining. There are some challenging parts of having Oscars in your aquarium, but it’s manageable. You just need to know the essential tips and plan accordingly.

It is not wise to put a newly bought Oscar in an existing tank, so you need to plan the Oscars’ entire tank. Keeping Oscars with other community tank fish instead of making a dedicated Oscar tank is tricky. I will not recommend this approach to noobs.  

This intelligent little creature will bring your fishkeeping experience to a new level. So, let me know your thoughts. If you are already an Oscar owner, I’ll be glad if you share your experience in the comment box.

Sujit Modak

3 thoughts on “Oscar Fish Care Guide, the Intelligent Aquarium Pet”

  1. Hi Sujit,
    I was searching for the options for pet. I have read your blog and love the way you have explain about the fish as a pet .(The Oscar Fish). You have covered all the minute details like water conditions, behavior of fish, disease and cure. Looking for new blogs from your side.
    You can also read about more best pets at https://hypoallergenicpetbreeds.com/category/best-pets/

    Michael Smith

    • Hello Michael,
      I visited your site and liked it very much. Though it’s a pet-related big authority site, the freshwater fish article ’10 Coolest Freshwater Aquarium Fish Pets’ caught my attention especially. (you can guess why) What I liked most about that article is the fish selection. Really they are the coolest ones. I’d be delighted to see more fish related articles on your site.

      Sujit Modak

      • Hi Sujit,
        Thanks for visiting and giving time to read my blog. I am in process of reading your more articles. Will connect you for any query or question in your blog.

        Michael Smith.


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