Oscar Fish
Scientific name: Astronotus ocellatus
Robust fish that needs very large aquariums and carefully selected tankmates.
Quick facts
- Approximate size25–35 cm
- Average weight800–1,500 g
- Life expectancy10–15 years (captivity)
- ActivityDiurnal
Basic information
- Habitat: slow-flowing rivers and flooded areas of the Amazon basin.
- Diet: large invertebrates, small fish, fallen fruits, and high-protein prepared food.
- Sexual dimorphism: not very marked; better distinguished by reproductive behavior.
- Predators: large predatory fish and some reptiles; juveniles are much more vulnerable.
Life in the wild
How this species lives in its natural environment, with the waters, shelters and resources it needs.
Species overview
The oscar is a large South American cichlid that combines intelligence with very high space and filtration needs.
Natural habitat
In nature it occupies temperate and turbid waters, with roots and logs that offer refuge and hunting areas.
Behavior
It is territorial and can be aggressive with other fish, especially in cramped spaces.
Special features
Its ability to interact with caregivers makes many people see it almost as an "aquatic dog".
Conservation and threats
In its native area it is considered relatively common, although habitat degradation is always a potential threat.
Curiosities
Striking details about this species that help better understand its biology and role in aquatic ecosystems.
- It can recognize the people who feed it and show "play" behaviors.
- It reorganizes the aquarium by moving stones and decorations.
- It has a powerful jaw and may try to bite if harassed.
- It has become popular for its personality, but many underestimate the necessary aquarium size.
Welfare profile
Summary of the most critical points if this species is kept in aquariums, ponds or specialized facilities.
Space and facilitiesHigh
It needs very large aquariums (minimum 200 liters for a single specimen) with powerful filtration.
Water quality and parametersHigh
It produces a lot of waste; requires powerful filtration and frequent water changes.
Handling and stressMedium
It can become aggressive with tankmates, especially in cramped spaces.
Oscar Fish in captivity
General information aimed at professional facilities, public aquariums and educational projects. It does not intend to promote capture or impulsive keeping of aquatic fauna.
⚠️ Before keeping fish like this species, it is essential to review local regulations, ensure adequate facilities and minimize impact on wild populations.
Suitable facilities
Only for experienced aquarists with large aquariums and carefully selected companions.
Feeding in responsible centers
The diet includes high-protein food, whole fish, and quality frozen food.
Handling and welfare
It is important to provide refuges and decoration that it can reorganize, as it is part of its natural behavior.
Ethical message
In education it can be used to talk about intelligence in fish, space needs, and responsibility in aquaristics.
Many aquatic species suffer from massive captures, uncontrolled trade and irresponsible releases. The priority should always be to protect rivers, lakes and seas, reduce pollution and consume seafood responsibly.