Oscar fish are known as “tiger oscars” and “marble cichlids” because of their black/brown and orange markings.

The oscar fish species is considered one of the most intelligent aquarium species, but oscar fish have an aggressive, territorial side that makes the fish challenging to manage.

Colors, Patterns, Fins, and Sex Differences
Oscar fish have brown/black bodies with red or orange marbling. Some oscar fish variations have green or olive bodies. There are albino variations of oscar fish, which have white bodies with red patterning.

With large, oval-shaped bodies, oscar fish are a stocky aquarium fish species. The fish have large heads, large mouths, and large eyes. They have fan-shaped fins that extend the length of the fish’s body.

Male and female oscar fish are identical in shape and color.

When oscar fish are born, the fish’s colors are dull, and their dark markings are deep black. The colors of the fish become brighter and the black markings turn gray as the fish grow. A stressed or sick oscar fish will look duller than usual.

The most common type of oscar fish is the tiger oscar fish, but there are other subspecies of oscar fish that have their own unique appearances.

Red oscars have fiery-red coloring, while albino oscars are white and red.

Crossbred versions of the oscar fish include:

blue oscars – typical oscar fish but with blue patterning
black oscars – black fish with white bands running around their bodies
white oscars – pale, pink fish
green oscars – typical oscars with green and yellow coloring

Typical Behavior
Oscar fish are intelligent fish that swim with purpose around the tank. The fish recognize their owners and can be hand-fed, giving them the nickname “river dogs.” The oscar fish’s intelligence is an appealing quality for aquarists.

However, oscar fish are territorial and have aggressive tendencies. You should carefully choose which fish to house with oscar fish in a community aquarium to prevent fighting and stress amongst the fish.

If oscar fish feel that their territory is being invaded, the oscar fish will attack their tank mates, push other fish around, and chase the other fish. Oscar fish fight with fish of their own species, especially during breeding season.

Oscar fish are quick swimmers and prefer to frequent the middle section of the tank. They require plenty of open space. Oscar fish occasionally swim to the bottom of the tank to search for food in the substrate.

Although the oscar fish is a social species, it enjoys the privacy of caves and plants to hide in.

In an aquarium setting, oscar fish are active during the day and rest during the night. The fish prefer frequent small meals throughout the day.