Species Profile-Oscar Cichlid (Astronotus) ocellatus


Scientific Name(s): Astronotus ocellatus, Acara ocellatus, Cychla rubroocellata, Hydrogonus ocellatus, Lobotes ocellatus

Common Name(s): Oscar Fish, Common Oscar, Red Oscar, Tiger Oscar, Red Tiger Oscar, Marbled Cichlid, Velvet Oscar, Albino Oscar

Family: Cichlidae

Species Type: South American Cichlid

Origion Range: Peru, Brazil, and French Guiana. Collected along the Amazon, including the Ucayali, Amazonas, Solimões, Içá, and Negro drainages, and also in the
Oyapock and Approuague drainages.

Natural Habitat: Amazon River Basin

Maximum Size: 14 inches, But have read that some have reached 16 inches or more.

Life Span: 10+ years

Temperature: 75°- 86°F (24° to 30° C)

Temperment: Semi-aggressive to Aggressive but very interesting, I have had peaceful Oscars and aggressive Oscars. You won't know which you have until you get to know it. In my experience they are fairly peaceful given enough space for territories. Many keepers experience begging around meal times or the seemingly playful greetings they receive from their fish when they get home.

PH: 6.0 to 7.5 (neutral)
Soft to hard water is tolerated

Diet: Omnivores, Oscars are found in slow-moving rivers that are heavily vegetated, they often stay around the banks for breeding, and nesting. They grow extremely fast and will eat a variety of foods including goldfish, crayfish, frogs, shrimp, High quality pellet food, frozen foods, and others, they love earthworms as well. They will appreciate a varied diet with lots of protein, Oscars in captivity are notorious for their gluttonous diets.

Minimum Tank Size: 75 gallons for a single full grown specimen 125+ for adults (Pair). These are minimum tank sizes and in my experience the more space given the happier and more peaceful they are.

Tank Region: All Over, mainly middle to bottom.

Possible Tank Mates: Firemouth Meeki, Jack Dempseys, Convicts, Serevums, larger catfish and plecos Other Oscars if the tank is large enough 125 gallons plus. Oscars can be tolerant of other tank mates if given space.

Filtration and setup: The most important thing you have got to provide your new Oscar with is good water quality. Being relatively high waste producing, this species requires a high water turn over and good biological filtration. Ideally the volume of the water in the tank should be turned over 10 times per hour. This may seem like a lot but Oscars are big messy fish that WILL NOT stand for foul water. If you are using canister type filters with larger amounts of biological media 6-7 times an hour will be fine. I'd like to add that the Oscar will be prone to certain disease, such as HITH and lateral line erosion. This is most of the time caused by poor water quality and small living spaces.

Your best bet for decor is going to be a thin layer of pea size gravel, large rocks, driftwood, and a nice looking background. Darker décor and gravel will bring an Oscars color out the best. Live plants aren’t recommended because of the Oscars desire to up root any live plants. Oscars will even pull fake plants out so if they are going to be used they should be held down with larger rocks at the base.

Sexing and Breeding: It is very difficult if not impossible to sex Oscars from physical characteristics alone, pairs have been observed to prepare a breeding area, this is typically a flat stone or a piece of slate. Aquarium temps should be 79-82 degrees and live foods should be fed to condition the pair. Eggs hatch typically in 3 to 4 days. A single spawning may consist of as many as 2000 eggs! Oscars reach sexual maturity at 4 inches and will form life long pairs. Unlike many other fish, the Oscars will actually care for their eggs and will take on the role of protector and anti-fungal agent for the roe. They also practice brood care once the babies have hatched, so it is safe to leave them with mom and dad for a while.

Coloration: The coloration of the Oscar fish can vary from olive-green to gray to chocolate brown in base color with a smattering of some or all of these colors. Black spots surrounded by an orange or red ring on the base of the upper caudal peduncle is a noteworthy characteristic of the Oscar.

There are a variety of color forms of this cichlid including:
Albino-Albino Oscar
Orange-Orange Oscar
Red Tiger-Red Tiger Oscar
Red-Red Oscar


Additional comments: The Oscar is probably the most popular of all the cichlids on the market today. Oscars are a very clever fish and many aquarists claim that each Oscar develops its own characteristic personality. Before buying your Oscars first take a second to make sure you are ready for the commitment that these fish require. These fish are not only beautiful, but also very intelligent. This combination of attributes is what makes this fish so attractive.

This being said a lot of people see these beautiful fish and don't realize how big they get, and how fast. Some people say it is ok to house these guys in a 55 gallon as a grow out. In my experience they grow very fast and adult size should be considered when buying an Oscar. Oscars are one of my favorite Cichlids and if you are going to get one or a pair you will be very happy and may end up with a great friend in the end.