Black Harlequin Rasbora tank mates
Trigonostigma heteromorpha
4 rated pairings from the Black Harlequin Rasbora care guide. Compatibility here means water, temperament, tank zone and adult size all line up — the note on each card says why. Black Harlequin Rasbora needs at least 10 gallons on its own; every companion adds to that.
Excellent matches
3 · Same water, complementary zones, no conflict.
Neon Tetra
Paracheirodon innesi
10 gal min · 1.5" adult · Peaceful
Similar size, water parameter requirements, and peaceful temperament make them ideal companions in a planted community tank.
Pygmy Corydoras
Corydoras pygmaeus
10 gal min · 1" adult · Peaceful
Bottom-dwelling, peaceful, and shares a preference for soft, slightly acidic water; occupies a different swim zone with no competition.
Chili Rasbora
Boraras brigittae
5 gal min · 0.8" adult · Peaceful
Tiny, peaceful nano fish that thrives in similar soft, acidic water conditions and complements the Harlequin's schooling behavior.
Good matches
1 · Compatible with normal care — watch space and numbers.Planning this tank?
Run the whole stock list through the calculator — it checks bioload and schooling numbers, not just pairings.