Comments: These Oscars retain the colors and patterns of their wild ancestors from the Amazon Basin. Most other aquarium Oscars have been selectively bred to show more red.

Origin: Oscars are members of a very large family of fish, which are called Cichlids. The ancestors of Oscars lived across wide region in the Amazon Basin in South America.

But now there are Oscars living in natural environments in China, Australia, and Florida, and many Oscars living in aquariums all over the world.

Maximum Size: In aquariums, males can grow to be more than 14" long, including their tails, which is not a good size for almost all aquariums.

Females are about the same size as males but get plumper, as they fill with thousands of eggs.

Oscars can grow to be even bigger, and DrTom once saw two Oscars that were over 18" long, living in an 800-gallon aquarium that seemed too small them.

They were said to be about 20-years old and greatly beloved by their proud owner, who said they'd spawned many-many times to produce a huge number of offspring.

Behaviors: Oscars are usually not aggressive fish, but they will swallow any fish that fits into their mouths.

They are very aggressive before spawning, during spawning, and when protecting their eggs and babies.

Compatibility: Some recommended tank mates include spiny catfish like Pictus Cats, plus Large Plecostomus, and other large fish.

Click here to read more about compatible groups of pet fish.

Temperature: Oscars live best from about 74 to 82-degrees F., with 78 being perhaps ideal.

Click here to learn about aquarium temperature, aquarium thermometers, and aquarium heaters.

Feeding: Premium Fish Food Pellets is the best type of food to feed Oscars, and can be fed to them throughout their entire lives.

As the Oscars grow larger their owners usually prefer to increase the size of the pellets gradually from small to medium to large pellets.

Oscars do not need to eat feeder fish, and feeder fish can cause a number of problems, so they are not recommended.

Click here to learn more about and shop online for premium fish foods.

Water Conditions: Their ancestors lived in the Amazon Basin in South America, where the water is usually soft and rather acidic, but apparently at times the pH and hardness increased in these water.

So Oscars can adapt to most types of water, and as usual it's best not to change water chemistry, unless you want to breed them, hatch the eggs, and raise the baby fish.

Click here for a lot more information about aquarium water conditions.

If water conditions are not kept very good, Oscars will get the so-called Hole in the Head Disease. Click here to learn more about that.

Aquarium Size: Oscars will grow fast and soon need to live in an aquarium with at least 80-gallons of water and eventually in an aqarium with hundreds of gallons of water.

Decor: Oscars do not need gravel, and a layer of gravel more than 1/4" thick will usually fill with bits of uneaten food that will contaminate the water.

Click here for more about aquarium gravel.

Live plants are beautiful and improve the water quality, but Oscars will usually dig plants up, so aquariums with Oscars rarely have live plants.

Aquarium Filter: Bio-Wheel Filters are highly recommended.

Most 80-gallon aquariums have room along the back for two Penguin 350B Filters, and this is sort of the minimum set up for Oscars.

Better is a 120, 150, 200-gallon and bigger aquariums with as many Penguin 350B Filters as will fit across the back.

Eventually even one Oscar will need a very large aquarium with a large filtering system.

Click here to learn more about aquarium filters.

The addition of Lava Rocks will keep nitrates in the ideal range. Click here to learn more about using Lava Rocks in aquariums.

Life Span: Oscars have lived for up to 20-years and possibly longer.

Gender: It's difficult to tell males from females, but females become plumper. When Oscars breed you can see their breeding tubes, and the female's tube is much larger than the male's.

But until they breed, it's difficult to tell their genders.

Breeding: At about 16 to 20-months of age Oscars will often begin to form pairs, picking a territory in the aquarium, and evicting the other fish from that territory.

They'll soon begin cleaning an area like the surface of a big flat rock and then lay eggs, guard the eggs for few day until they hatch, and then guard their babies.

Click here for a lot more about breeding various tropical fish in aquariums.

Popularity: For a long time Oscars have been very popular aquarium fish.

Names: Their scientific name is Astronotus ocellatus. No one seems to know why these lovable fish are called Oscars. It's a funny, lovable, and somehow appropriate name.

There are now at least two species of Oscar Fish in the genus Astronotus, but there is DNA based genetic evidence of five species that are closely related and may have hybridized to create the aquarium Oscar.

This is true of several other aquarium fish and is really nothing to worry about.

Variations: There are many variations in shape and coloration, and many of those variations are sold by us.

Click here for a lot more information about keeping and caring for Oscars, including a picture gallery.

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