Due to their aggressive, territorial personalities, oscar fish shouldn’t be housed with the majority of fish species.

Although oscar fish are used to being surrounded by other fish species in the wild, tensions can rise in a tank with limited space, causing fights, bullying, and fin-nipping. Housing these fish alone is best.

However, if you wish to establish a community tank, choose large, passive fish that won’t get in the way of oscar fish.

Great tank mates for oscar fish include:

• Bichirs
• Firemouth cichlids
• Silver dollars
• Jaguar cichlids
• Green terrors
• Sailfin plecos
• Convict cichlids
• Arowanas
• Severum cichlids

If you plan to house oscar fish together, make sure there’s enough room in the tank. Use a 55-gallon tank for one oscar fish, and add an extra 30 gallons for each additional fish.

Don’t add small fish or invertebrates, like shrimp and crabs, to the tank because oscar fish eat any fish that are smaller than their own size.

Diet and Feeding
In the wild, oscar fish eat a varied diet of larvae, small fish, and plant matter. As omnivorous, opportunistic fish, oscar fish eat anything they can find, and you should replicate this varied diet in captivity.

Feed oscar fish a combination of store-bought pellets or flakes, live/frozen food like daphnia and brine shrimp, and plant-based foods like algae wafers or green vegetables. Oscar fish have natural hunting instincts and enjoy catching and eating live food.

Split feeding into two or three sessions per day. In each session, only feed the oscar fish as much food as they can eat within two minutes.

Breeding
Breeding oscar fish in captivity is difficult and often requires a lot of fish. Oscar fish are picky about their mates, and putting a male and female in the same tank in the right conditions doesn’t guarantee breeding success.

However, if you’re adamant about breeding oscar fish, here’s what you should do:

1. Select a mature male and a mature female oscar fish (the fish typically mature after reaching one or two years old).
2. Place the male and female in a separate breeding tank decorated similarly to the home tank. Lower the temperature of the water by a couple of degrees to mimic the rainy season of their natural habitat, which encourages breeding in the wild.
3. Change the water every couple of days and sprinkle water on the surface to aerate the tank. Feed the fish a varied diet of live and frozen foods.
4. If the pair are interested in one another, both fish will flare their gills and waggle or vibrate their tails. If the pair show no interest in one another or begin to fight, separate the fish and try with another pair, or try a new female with the same male.
5. After successful breeding, the female will lay up to 3,000 eggs on a clean rock surface.
6. The parents will guard the eggs for up to three days until the eggs hatch.
7. Remove the male and female after the eggs have hatched to prevent the parents from eating the babies.
8. Raise the fry in the tank with an added sponge filter and feed the fry specialized food for young fish, four times per day.

Should You Get an Oscar Fish for Your Aquarium?
If you’re planning to set up a new tank, preferably dedicated to a single fish species, oscar fish are a good choice to consider.

However, if you’re a beginner aquarist, or your tank already houses fish that oscar fish could bully or eat, oscar fish aren’t suitable for you. Oscar fish aren’t high maintenance, but the fish are known to fight and show signs of aggressiveness.

In the right environment, oscar fish are beautiful, colorful fish that exhibit intelligent, unique social behaviors.