tiger oscar cichlid care guide header

It is fair to say that you will either love Tiger Oscar Cichlids or hate them.

When compared to other tropical fish, they are giant, graceful creatures with bold personalities and markings to match.

They are well suited for people ready to try a larger fish tank and fish.

tiger oscar cichlid in aquarium

Quick Intro To Tiger Oscar Cichlids

Family NameCichlidae
Scientific NameAstronotus ocellatus
Common NamesVelvet Cichlid, Tiger Oscar, Oscar Fish
Care LevelModerate to difficult
Region of OriginSouth America, Amazon River basin
Distant RelativesRed and Lemon Oscars, Albino Oscars, Other South American cichlids.
Habitat TypeRiver settings with sandy substrate and plenty of hiding places for potential prey.

General Appearance

This is a somewhat pointed oval shaped fish with olive green and black mottling as its main body color. From the gill covers back, it has cryptic bright orange markings. It also has sleek, low profile black fins and a rounded tail.

Males vs. Females

Males and females look mostly the same. Males may get slightly larger, and will be more colorful prior to mating.

How They Move in the Tank

Overall, they are powerful swimmers and also have both the size and agility to fight just about any other fish that bothers them.

Optimal Water Conditions For Tiger Oscar Cichlids

Since Tiger Oscar Cichlids will need a large tank, or even a pond, it can take several months before the water completes its first nitrogen cycle. Never buy these fish until you are certain the tank or pond is fully cycled and can handle the sudden increase in bioload. 

Water Temperature74 – 81 degrees fahrenheit
Water Flow RateSlow
pH6.5 – 7.5 (neutral or close to neutral works best)
Aquarium Salt (Y/N)Use with caution. I don’t personally recommend using Aquarium Salt as a replacement for good water chemistry and environment management.
Tannins (Y/N)You can give it a try if the fish seems shy of bright lights and seems comfortable on the acidic side of the neutral pH level.

Because these fish do produce a lot of waste, I recommend taking the additional step of using small fish for about 8 months to a year to further break in the water. After that, you can take the smaller fish out and put them in another home aquarium.

Tank Setup

Minimum Tank Size55 gallon per fish for juveniles and younger fish. As the fish matures, you will need a larger tank as they become very stressed and aggressive in cramped spaces.
Optimal Tank Size150+ gallons
Best Filter TypeUse an external canister filter with the capacity to filter twice the amount of water held by the tank. Also use bubble up filters with floss and activated carbon to increase the surface area for nitrifying bacteria. 
Extra Air and How to Provide ItAir curtains set to low or moderate capacity. 

Optimal Tank Shape

Long, wide, and tall. Even though these fish tend to stay in the mid and lower regions of the tank, they can also be powerful jumpers. 

Together with a tight fitting lid, leave a few inches of room at the top of the tank. These are large fish, so if they do bang into the aquarium lid, it is likely they will either get hurt or disrupt it. The more space cushion you can give between the lid and the water surface, the better.

Testing Schedule First Year

Test weekly for pH, ammonia, nitrates, nitrites, and hardness.

Testing Schedule After 1 Year

Since this fish will continue to grow after the first year, it will also continue to increase the bioload in the tank. Continue testing weekly for ammonia, nitrates, nitrates, pH, and hardness for the first 2 – 3 years. After that, you can cut back to monthly testing.

two tiger oscar cichlids swimming

Creating the Landscape

Rocky substrate or gravelNo, because these fish like to dig and sharp surfaces can scratch their slime coat and increase the risk of infection.
Sandy substrateYes.
Overhangs and cavesYes, but make sure they are big enough for the fish to swim around in as it grows. I have seen these fish grow in size, and wind up getting stuck in places they used to swim through just fine.
Open waterYes
Densely plantedPatches
Best PlantsPut rooted live plants in pots, or use mesh coverings over terraces where the roots are to keep this fish from digging them up. Floating plants will work fine.
Best LightingLow to medium
Best DecorationsDriftwood (be sure to remove the tannins), plants, rounded or smooth rocks, caves
Decorations to AvoidAvoid plastic plants that this fish can rub or scratch against. Also try to avoid toys holes in them that the fish can get part of the way through. Tiger Oscar Cichlids are very curious creatures and can get stuck in tight spaces and holes that accept part of their body, but not all of it.

Physiological Considerations

Maximum Size12 – 18 inches or more
Rate of GrowthWill reach full size in about 2 years. 
Life Span20 years or more.
Preferred Tank RegionMiddle to bottom
Scale ThicknessThese fish have fairly sturdy scales. It is safe to use most freshwater antibiotics on them. 
Gill ConsiderationsThese fish have fairly large, strong gills. Since they are adapted for slow moving waters, they are not usually susceptible to gill flukes or other diseases. 
Swimbladder ConsiderationsSince these are not deep bodied fish, they usually have little or no problem regulating their position in the tank. 
Fin Shape ConsiderationsThese fish have compact, powerful fins that make it easy for them to sprint as well as move around with great agility.


Aggressive fish. Tiger Oscar Cichlids do have teeth in their jaws as well as in their throats. Exercise caution when placing your hands in the tank, as these fish can and will attack. They will be more likely to attack when eggs are present in the tank, or mating is about to occur.

I highly recommend using temporary partitions between you and the fish if you have to put your hands in the tank for any reason. While it may seem cool and fun to have younger, smaller fish nibble on your fingers, it isn’t so much fun if they decide to bite later on.

A great deal will depend on your relationship with the fish and its temperament. I’ve had some that I could pet easily throughout their lives. Others, I would not trust unless I had sturdy gloves on or a partition between my hand and their mouth.


Male and female Oscar Cichlids can be quite aggressive. This includes among themselves as well as towards other fish. They are born hunters and you cannot expect them to behave any other way despite their curiosity and capacity to be creative thinkers.

Male to Female Ratio

Tiger Oscar Cichlids are very territorial among themselves as well as with other fish. It is almost impossible to determine their gender when they are younger, as well as to figure out whether older fish are fighting or courting.

Once you know you have a breeding pair, it is best to put them in a tank by themselves, or use partitions to separate them from others in the tank.

Schooling Behaviors

As a general rule, Tiger Oscar Cichlids don’t form schools in captivity. The most you can expect is for these fish to sort of co-exist with each other provided there is enough space for each fish to claim its own territory.

Suitable Tankmates

Other large Oscars and Cichlids. They will also do Ok with Arowanas provided there is enough room. If you want to keep these fish in any kind of community setting, it would be better to use a pond.

Species to Avoid

Avoid any creature that is smaller or more peaceful than Tiger Oscar Cichlids. They will see everything from snails and freshwater shrimp to smaller Cichlids as prey.

Common Behaviors You May See in Aggressive Tiger Oscar Cichlids

Changes in Eye ColorYes, however black coloring signifies the fish in question lost the battle.
Circling with Fins SplayedYes
Fins Splayed as Other Fish Approach or When Approaching Other FishYes
Intensified ColorsYes
Mouth to Mouth BitingYes

It should be noted that aggressive signals in Tiger Oscar Cichlids are very similar to mating signals. I would give more credit to these signals being pure aggression in younger fish as opposed to older ones that have already established themselves as a breeding pair.

When it comes to younger fish, you will have to watch carefully and make sure you know how to handle any injuries that occur. Also, pay attention to the signals and cues from the victim fish. 

Individuals that are courting aren’t as likely to dart away when a prospective partner approaches or show other signs of fear. On the other hand, a male fish that is being harassed by another male will most certainly show signs of fear such as hiding, or moving their eyes frantically.

Anti-Bullying Solutions That Work Best With Tiger Oscar Cichlids

Add More Fish of the Same SpeciesNo
Change Feeding Methods, Quantity, or Number of FeedingsIncrease the number of feedings.
Increase Number of Hiding PlacesNo
Isolate the Bully Yes
Move Decorations to Shake Up Territorial BoundariesYes, however this may only last for a few days. These fish are fast learners!
Move to a Bigger TankYesWater Chemistry or Temperature ChangesIncreasing water temperature will spur breeding behavior and also aggression levels. You can try lowering the temperature during non-breeding times.

Add More Males or Females

I don’t recommend adding more of the same species because these fish actually start courting at around 6 months of age, even though they will not mate for another 2- 3 years. 

It is hard to say if the window for beginning this process will close too quickly, and in a way that would make adding more fish to curb aggression a thankless task.

Gender and Reproductive Considerations

If you purchase fish designated for home, or hobby aquarist tanks, it is likely they will not be suitable for breeding. Even if you do get them to mate, it is likely the eggs will be non-viable, or the juveniles will be deformed. 

If you want to breed Tiger Oscar Cichlids, start out with an aquarium large enough to house at least 6 – 8 fish. From there, you may or may not wind up with at least one breeding pair. The easiest way to get started is to purchase a pair of 2 -3 year old fish from a reliable breeder selling them for that purpose.

How to Recognize Breeding Pairs

During the courtship process, they may lock jaws with each other, chase, and flare up their fins. Later on, they will work on cleaning rocks together of debris, as well as swim close to each other.

How Many Babies?

Younger females will lay around 500 eggs, while fish in their prime can lay up to 3000 eggs per spawning cycle.

Separate Hatchery?


Special Needs for the Fry

Adult fish will watch over the eggs and defend the nest.

Managing the Babies

After the fry are hatched, you will need to watch them carefully, as larger fry will hunt and consume smaller ones of their own species. You can separate them out, or simply wait for the largest ones to dominate the hatchery.

Feed fry commercial fry food for egg layers. Once they are big enough, you can feed them baby brine shrimp, live insect larvae, and crushed staple fish food.

Nutritional Needs

tiger oscar cichlid close up

Tiger Oscar Cichlids considered omnivores, even though they mainly consume meat. They do enjoy some vegetable matter, however it should not be the main staple for them.

Wild FoodsInsects, small aquatic animals, other fish, sometimes bits of plants
How ObtainedTiger Oscar Cichlids are avid hunters. They are messy fish that will dig in the substrate looking for food as well as snatch it directly from the water. 
How to ReplicateYou can introduce live food into the tank daily, or try to establish colonies of feeder animals in the tank.
Best Sustenance FoodPellet or flake food formulated for South American Cichlids. I do not recommend using flakes with young fish because the flakes can get stuck in their throat and choke them. 
Additional Foods for Optimal HealthFrozen meat based foods such as blood worms, tubifex worms and daphnia.
Special Foods for Color and GrowthCrickets, earthworms, mealworms, Iive freshwater shrimp, live brine shrimp, small minnows and other feeder fish, Vitamin C supplements made for Cichlids
When and How Often To Feed based on Place in Life CycleFeed juvenile fish 3 – 4 times daily, especially if there is more than one fish in the tank. You can try cutting back to 2 times per day for adult fish, but may need to go back to smaller feedings several times a day if they become aggressive.

Finicky Fish Management Troubleshooting Checklist

Check (and get rid of) Ammonia and NitritesYes
Lower Nitrates to Level Suitable for Tiger Oscar CichlidsKeep below 20 ppm
Test (and Adjust if Needed) Other Water Chemistry ParametersYes
Check for IllnessYes
Look for Signs of Bullying Such as Missing Scales, Nipped Fins or other DamageYes
Try These Frozen/Thawed or Live FoodsFresh, live foods such as brine shrimp or live insect larvae

Observe for Possible Environmental Stresses

Too Much/Too Little Light – Usually too much light can be a problem. 

Sounds – Yes.

Vibrations – Yes.

Odors From Air Sprays, Cooking, Construction, etc – Yes.

Common Diseases and How to Avoid and Treat Them

Because Tiger Oscar Cichlids can get into a lot of fights with other fish, you should always be on the lookout for fungal and bacterial skin, mouth, fin, and tail fish diseases.

How to avoid species-specific diseases

These fish are a bit more susceptible to Hole In the Head Disease (Hexamita) than other fish.

Best antibiotics

You can use any antibiotic designated as safe for Cichlids.

Treatments to avoid

Avoid formulas with salt, especially if you already use it as a preventative in the tank. Too much salt can pose a danger to a freshwater fish.

Food recommendations

Live foods that will stimulate their appetite. Also introduce medicated flakes or pellets to help prevent internal, opportunistic parasites from making the fish even more sick.

Isolation or Hospital Tank?

Yes, but only if other fish are harassing them.

3 Interesting Facts About Tiger Oscar Cichlids

  1. Tiger Oscar Cichlids mate for life and are monogamous. These pairs, in turn, can be aggressive to other fish that interfere in their territory.
  2. These fish make grunts and other sounds that may only be audible under water. They can communicate with each other using both visual and auditory cues.
  3. Even though these fish are not considered an invasive species, they often wind up being released into the wild by owners that can no longer take care of them. At some point, this is bound to be a problem, especially in regions with warm enough waters all year round.

Before you purchase this aquarium fish, make sure you can return it to the pet store years later. It is possible that other aquarium keepers will need a new fish of the same age as their own, so there is a chance the fish can be rehomed.

Overall, Tiger Oscar Cichlids are fascinating creatures. They will do well in home tanks provided the setup is large enough, and you take some precautions when choosing tank mates.

About The Author

2 thoughts on “How to Care for Tiger Oscar Cichlids: A Complete Fact Sheet, Breeding, Behavior, and Care Guide”

  1. Robert Phillips

    My Tiger Oscar is sick for the last few days, it just lays on the bottom of the tank and struggles to breath

  2. My Oscar has a mouth fungus and won’t eat , I treated it but can’t seem to get rid of it all the way , help!

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