← All species
Oscar (Astronotus ocellatus)
AI illustration, not an ID reference

Oscar

Astronotus ocellatus

FishFreshwater

Care level
Moderate
Temperament
Aggressive
Recommended tank
400 L
Maximum size
35 cm
Temperature
23–28 °C
pH
6–7.5
Diet
Carnivore

Care at a glance

The oscar is the dog of the aquarium world: it recognises its keeper, comes to the glass, feeds from the hand and has unmistakable character. For many people that is exactly why they get one — and for just as many, the reason they want rid of it within a year.

It reaches thirty-five centimetres, produces an enormous amount of waste and cheerfully rearranges your whole layout, plants included. Plan on a big tank, heavy filtration and frequent water changes. Anything that fits in its mouth counts as food. Feed quality pellets rather than live feeder fish: the latter brings disease risk and a one-sided diet.

Good to know

  • Outgrows most home tanks
  • Preys on shrimp and snails
  • Eats or uproots live plants

Best not combined with

Related species

Keep Oscar in the BlubHub app

Add this species to your inhabitants, with count and photos, and see the care info next to your own water values, target bands and reminders. Free, no account, everything on your own device.

More about the app →

Values are mainstream hobbyist guidance, not gospel — always watch what your own animals need.