Black Harlequin Rasbora

Black Harlequin Rasbora

Black Harlequin Rasbora (Trigonostigma heteromorpha) is a melanistic color morph of the Harlequin Rasbora — the body coloration is dramatically darkened, with deep charcoal to near-black replacing the standard warm copper-orange. The defining black triangular wedge is retained but appears as a darker-within-dark contrast on the melanistic body. A striking and dramatic alternative to the standard form.

Feeding & Care Tip: Sera Vipan Tropical Flakes and Hikari Micro Pellets make excellent daily staples. Supplement 2–3× per week with Hikari Frozen or Freeze-Dried Baby Brine Shrimp, Hikari Frozen or Freeze-Dried Tubifex Worms, or Hikari Vibra Bites. Feed small amounts 2–3 times daily.

The genus Trigonostigma was established in 1999 to separate this group from the enormous catch-all genus Rasbora. The name means 'three-spotted' in Greek — referencing the triangular black marking that defines the group. All five members of the genus spawn in the same distinctive way: the female inverts to lay eggs on the underside of broad-leaved plants such as Cryptocoryne or similar surfaces, with the male fertilizing immediately below. The melanistic form is produced by selective breeding that enhances dark pigmentation throughout the body. The result is a dramatically dark fish whose silhouette contrasts powerfully against green plants in a planted aquarium.

Keep in groups of at least 8. The dark body creates a striking contrast against green plants — particularly effective in a heavily planted aquarium. Can be mixed with standard or Purple Harlequin Rasboras for a multi-tone school. All care requirements identical to the standard Harlequin.

The spawning behavior of Trigonostigma rasboras is unique and fascinating — the female inverts completely to place eggs on the underside of a broad leaf, then the pair separate and the eggs develop without parental care. Cryptocoryne leaves are the traditional natural spawning site.

Care & Ideal Parameters