Cichlids · Astronotus

Oscar

Astronotus ocellatus · Slow rivers and floodplains of the Amazon

Photo: Jón Helgi Jónsson (Amything), CC BY-SA 3.0, via Wikimedia Commons

The Oscar (Astronotus ocellatus) is a freshwater fish from Slow rivers and floodplains of the Amazon, where it lives in flooded forest habitat. Adults reach about 33 cm (13 in). Keep it at 20–28 °C (68–82 °F) and pH 6–7.5, in calm water. It is semi-aggressive. Feed meaty foods: frozen bloodworm, brine shrimp and quality sinking pellets.

At a glance

Water temperature

20–28 °C 68–82 °F

6–7.5 neutral water

Adult size ≈

33 cm 13 in

Swims ≈

Mid-water and bottom mostly in open water

Keep together ≈

Fine alone

Current

Calm still or slow water

Food

Meaty foods

Temperament

Semi-aggressive

Where it comes from

Home water

Slow rivers and floodplains of the Amazon

Lives in flooded forest habitat.

The dot marks where it's collected. Home from iNaturalist native sightings (117). Map: Natural Earth.

Oscar

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Cichlids · AstronotusLC

Predator. Eats any fish that fits in its mouth.

Oscar

Astronotus ocellatus

Slow rivers and floodplains of the Amazon · flooded forest

Temperature: 20–28°C
pH: 6–7.5
Adult size: 13 in · 33 cm
Flow: Calm
Swims: Mid-water and bottom
Temperament: Semi-aggressive
Diet: Carnivore
Group: 1+
Typical price: $15–40
Status in the wild: Least concern

Predator. Eats any fish that fits in its mouth.

Scan for the full profile
savethelittlefish.org/species/oscar/

Photo: Jón Helgi Jónsson (Amything), CC BY-SA 3.0

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Sources

We name everyone whose work is on this page. Where sources disagree, we show the best one: a scientific paper first, then aquarium references.

Temperature, ph, adult size, water flow, temperament, behaviour, group size, home range Seriously Fish: Astronotus ocellatus profile Website
Diet, conservation status, adult size, water flow, home range, ph, swim level, behaviour FishBase: Astronotus ocellatus summary Website Says: pH 6–?
Photo Jón Helgi Jónsson (Amything), CC BY-SA 3.0 Wikimedia Commons
Home range iNaturalist native sightings (117), iNaturalist community Website
Map of rivers and countries Natural Earth public domain map data Map

Not checked yet: habitat, group size, price. These are our own estimates from typical hobby ranges. We haven't checked them against a published source yet.

Know a good source for this fish? Tell us

Tank mates

Checked against a roomy 300 L planted tank with low flow and plenty of caves. Your own tank may change the answer: try it in Your tanks.

Good together

Keep apart

Small enough to be eaten

Agassiz's dwarf cichlid Amano shrimp Angelicus L136 Betta (Siamese fighting fish)Black skirt tetra Boeseman's rainbowfish Bolivian ram
Need a different pH and aggressive and small enough to be eaten

Auratus

In the hobby

Where to find it

No store or breeder we know of has it right now.

Run a store? List the fish you usually have. Breed fish? List your fry.

Tanks with this fish

No shared tanks have this fish yet. Share yours from Your tanks.

From keepers

Notes appear here when a keeper shares a tank with this fish and writes about it.

Questions keepers ask

How big does an Oscar get?

About 33 cm (13 in) as an adult.

What temperature does an Oscar need?

20–28 °C (68–82 °F).

What pH does an Oscar need?

pH 6–7.5.

Does an Oscar need to be kept in a group?

No. It can be kept on its own.

Is the Oscar aggressive?

It can be. It is semi-aggressive, so choose tank mates carefully.

What does an Oscar eat?

Feed meaty foods: frozen bloodworm, brine shrimp and quality sinking pellets.

Where does the Oscar come from?

Slow rivers and floodplains of the Amazon.

What fish can live with an Oscar?

Good tank mates include Candy stripe (L015), Zebra (L046), Agassiz's dwarf cichlid, Amano shrimp, Boeseman's rainbowfish.

All the numbers

Temperature min (°C)	20	Sourced
Temperature max (°C)	28	Sourced
pH min	6	Sourced
pH max	7.5	Sourced
Adult size (cm)	33	Estimate
Flow	Low	Sourced
Habitat	floodplain	Estimate
Smallest happy group	1	Estimate
Temperament	Semi-aggressive	Sourced
Diet	Carnivore	Sourced
Behaviour tags	eats_small_fish	Sourced
Typical price min (CAD)	15	Estimate
Typical price max (CAD)	40	Estimate

Some values are estimates from typical hobby ranges and haven't been checked against a source yet.