Astronotus Ocellatus

Datasheet

General Description

Astronotus ocellatus, also known as Oscar, is a popular cichlid species often referred to as the 'velvet cichlid,' 'red oscar,' 'tiger oscar,' or 'marble cichlid.' It can live for 10-20 years and comes in various ornamental strains. The species can feed on smaller fish, insects, crustaceans, zooplankton, and vegetation, with a preference for meatier foods like fish. Oscars are classified under the order Perciformes and belong to the family Cichlidae.

Aquarium Setup

The Oscar requires a tank of at least 540 liters and should not be combined with smaller fish due to its predatory nature. Tankmates can include characids, anostomids, other cichlids, and larger catfish species. A natural-style aquarium setup with a sandy substrate, driftwood, and dim lighting is preferable. The species may dig into the substrate, so careful consideration of tank decorations is necessary.

Behavior

While not overly aggressive for its size, Oscars should be kept with caution as their predatory behavior may pose a threat to smaller tankmates. They are known for their voracious appetite and can be fed with a high protein diet. Oscars exhibit unique behaviors such as thanatosis, where they play dead, and may become beggars for food if overfed. Proper feeding and consideration of tankmates are essential for their well-being.

Feeding and Diet

As generalist omnivores, Oscars feed on various items such as live or frozen foods, cichlid pellets, earthworms, prawns, and river shrimp. It is crucial to avoid mammalian/avian meat and feeder fish for their diet due to health risks and nutritional limitations. Maintaining a balanced diet is important to prevent obesity and other health issues in Oscars.

Reproduction & Dimorphism

Oscars are substrate spawners that form extended pair bonds during breeding. It is recommended to start with a group of young Oscars to allow natural pairing. The pair will select a spawning site, where the female may lay up to 2000 eggs. After hatching, the fry receive parental care until they are free-swimming. Male Oscars may appear slightly larger and more colorful than females but generally lack external sexual differences.

Habitat and Distribution

Found in the Amazon region, Oscars inhabit slow-moving or still waters in forested areas. They prefer silt-laden white water habitats with submerged tree roots or marginal vegetation for cover. Distributed across countries like Colombia, Brazil, Peru, and Argentina, Oscars are also present in feral populations in countries like Singapore and the USA. Wild-caught Oscars are occasionally available in the trade, but most originate from commercial breeders in Eastern Europe or the Far East.

Etymology

The genus name Astronotus is derived from the Ancient Greek words for 'celestial body' and 'back' or 'south,' while the species name ocellatus means 'having small eyes,' referring to the distinctive spot on the caudal peduncle.