Wild Oscar Fish Species Profile – How to Care Wild Oscar Fish

The Wild Oscar Fish is the original species of Astronotus ocellatus; all other Oscar variants in the hobby were derived (through selective breeding) from the Wild Oscar. Wild Oscars will grow out to be larger than the selectively bred Oscar variants as they are the original species, collected directly from the Amazon basin. They are one of the hardiest and most popular Cichlids in the hobby and can learn to distinguish their owner(s) from strangers as well as associate them with food. Wild Oscars are very intelligent and will develop and display unique and interesting personalities. In addition to their constant “begging” for food, they can also be trained to eat from their owner’s hand; which is why they are sometimes referred to as river or water dogs.

Wild Oscar Fish Characteristics

Wild Oscar Fish 1

The Wild Oscar Fish , or simply “wild oscar” or “w O”, is a predatory freshwater fish known for its large size, distinctively-spotted markings, aggressive temperment, and predatorial behavior in the mid to upper levels of the water column. With their large size they can be a danger to any fish that is not too big for the oscar fish to swallow whole.

Wild Oscar Fish Characteristic: predatory, territorial, aggressive.

*Properly called Astronotus ocellatus , all wild Oscars originate from South America. Tropical regions of Costa Rica and Venezuela are specifically noted as the native region. The Fild Oscar Fish is usually dark brown, black, grey to olive green in color with varying degrees of mottling.

Wild Oscar Fish Origin

Wild Oscar Fish originate from the warm tropical regions of Costa Rica and Venezuela. As a result they are typically found in similar habitats when kept as a pet.

Wild Oscar Fish Size

When fully grown, wild oscar fish can grow to be 12″ or more in length and live up to 10 years or more. A full-grown female will typically reach a maximum size of 5 or 6 inches while males can easily touch 10″.

Wild Oscar Fish PH

6.0-7.5 is the optimal range for Wild Oscar Fish to be kept in, however they can survive in a wide variety of conditions as long as extremes are avoided. pH below 5 will begin to cause stress if not death, while any pH above 8 will cause severe damage to their skin.

Wild Oscar Fish Colors and Markings

When kept in captivity or as pets, wild oscar fish are commonly found with less contrasting spots than their wild counterparts. Wild oscars typically have dark to light brown bodies with varying degrees of black spots outlined by white. A wide variety of different color mutations are available, including black oscars and albino oscars.

Wild Oscar Fish Aquarium

Wild Oscars Fish are a moderately large species of fish that require a lot of water to live in. A minimum 75 gallon aquarium provides ample space as long as it is filled right up to the very top as they do not like to have their head near the water due to the fact that they cannot breathe air. A canister filter rated for at least twice as many gallons as your tank holds is strongly recommended , and weekly water changes of up to 50% are required .

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 Wild Oscar Fish Tankmates

Wild Oscars Fish will prey on any fish small enough for them to swallow whole and kill any fish large enough that they cannot. Other than this rule, wild oscar fish can be kept with other species as long as it is an appropriate match in terms of size and temperament.

Wild Oscar Fish Care

Wild Oscars Fish are a tropical species that will be stressed if the temperature drops below 25°C or 77°F, and are likely to become sick if the water temperature is allowed to drop below 18-20°C or 64.4-68°F for long periods of time. They require a varied diet consisting of meaty foods such as bloodworms , earthworms , shrimp , krill , crickets and beef heart .

Wild Oscar Fish Lifespan

If properly cared for, wild oscar fish can easily live 10 years or more. As with most other cichlids they are extremely long-lived when compared to their size as some specimens have reached 15 years old in captivity!

Wild Oscar Fish Diet and Feeding

Wild Oscar fish are voracious predators that will eat anything they can fit into their mouths. They require a protein-rich, meaty diet of live food such as bloodworms , earthworms , shrimp , krill , crickets and beef heart .

Wild Oscar Fish Differences

There are a few differences between wild and captive-bred oscars. In the wild, they have more vivid coloring with distinct dark spots outlined by white on their bodies. Their eyes also have a yellow color, which is not present in most pet oscar fish due to selective breeding. Wild Oscar Fish can live for more than 10 years in captivity.

Wild Oscar Fish Breeding

Wild Oscar Fish breed in the wild only in their native warm waters and in temperatures ranging from 19-29°C or 66.2-84.2°F, with optimal breeding occurring at 22-26°C or 71.6-78.8°F. They are open monogamous substrate spawners that breed in caves created by rocks or roots, with one pair occupying the cave at a time. The female lays 30-50 eggs before both parents scatter them along the walls of the cave where they are fertilized .


As stated above, Wild Oscar Fish are often not the best choice for a pet due to their enormous adult size and their need for pristine water conditions. That said, they make excellent pets when provided with the right environment and enough space, as well as their large size making them impressive predators!