Marble Oscar tank mates
Astronotus ocellatus
5 rated pairings from the Marble Oscar care guide. Compatibility here means water, temperament, tank zone and adult size all line up — the note on each card says why. Marble Oscar needs at least 75 gallons on its own; every companion adds to that.
Excellent matches
1 · Same water, complementary zones, no conflict.
Good matches
2 · Compatible with normal care — watch space and numbers.Severum
Heros severus
55 gal min · 8" adult · Semi-aggressive
Similar size and temperament; both large South American cichlids that can coexist in spacious tanks with adequate territory
Jack Dempsey
Rocio octofasciata
55 gal min · 8" adult · Aggressive
Comparable aggression and size; requires 75+ gallon tank with plenty of space to minimize conflict
Use caution
2 · Works in the right setup; read the note before combining.Firemouth Cichlid
Thorichthys meeki
30 gal min · 6" adult · Semi-aggressive
Smaller than Oscar; may be bullied or eaten; only suitable in very large tanks with multiple hiding spots
Silver Dollar
Metynnis argenteus
55 gal min · 6" adult · Peaceful
Schooling fish that may trigger Oscar predatory instinct; only viable in 100+ gallon tanks with fast-swimming space
Planning this tank?
Run the whole stock list through the calculator — it checks bioload and schooling numbers, not just pairings.