Harlequin Rasbora Care Guide
Trigonostigma heteromorpha · Easy care · 10 gallon minimum
A hardy copper-and-black nano schooler that pops against green plants and dark substrate.
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How big does a harlequin rasbora get?
A harlequin rasbora (Trigonostigma heteromorpha) reaches about 2.0 inches as an adult. Plan tank size and tank mates around the adult size, not the small fish you buy at the store.
Tank size & setup
Give a harlequin rasbora a minimum of 10 gallons, with water at 73–82°F and a pH of 6–7.5. Keep them in groups of at least 8 — they are shoaling fish and become stressed and washed-out alone. As a easy-care, omnivore species, a stable, cycled tank with the right diet keeps them healthiest.
Good tank mates
Pair a harlequin rasbora with peaceful species that share its temperature and pH range. Compatible options include:
- Neon Tetra — 1.5", 10g min
- Guppy — 2.0", 10g min
- Molly — 4.0", 20g min
- Platy — 2.5", 10g min
- Zebra Danio — 2.0", 10g min
About the harlequin rasbora
The harlequin rasbora is a small fish in the family Cyprinidae. The species became an instant favorite among aquarists after its introduction in the early 1900s and is the best known and most widely kept species among the rasboras. In 1935, an image of a trio of harlequin rasboras, stamped in 14k gold, graced the cover of the first edition of William T. Innes's classic Exotic Aquarium Fishes, and remained through all 19 editions.
Recommended gear for harlequin rasboras
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