Encyclopaedia
Harlequin Rasbora
Trigonostigma heteromorpha
The Copper Wedge (1.5 - 2 inches / 4-5 cm). The Harlequin Rasbora is a legendary, bulletproof beginner schooling fish. Instantly recognizable by its deep, metallic orange/copper body stamped with a massive, pitch-black triangular 'pork-chop' or wedge shape on its back half. They are famous for being incredibly tight schoolers, moving together in a highly synchronized, stunning flash of copper. Unlike Tetras or Barbs, they are 100% safe to keep with Bettas.
Share
Check out Harlequin Rasbora on Atlarium
22 - 28 °C
5 - 7.5
Freshwater
Middle
5 cm
>= 54 L
>= 8
1 - 12 dGH
1 - 8 dKH
25 - 260 ppm
39 - 406 uS/cm
Species description
Care, breeding and tankmates
Geographic Origin and Distribution
Origin
Fish profile
- Temperament
- Semi-aggressive
- Diet
- Omnivore
- Sex ratio
- School
- Feeding frequency
- Twice daily
- Bioload
- This species produces very little bioload due to its small size. Weekly water changes and standard filtration are adequate to keep parameters pristine. Still, their schooling nature means the total bioload of the group must be considered.
- Flow
- Stagnant
- Reproduction
- Oviparous
- Compatibility & tankmates
- They are exceptionally peaceful and make great community fish. They should never be kept with large or aggressive tank mates that might eat them. Ideal companions include small tetras, peaceful bottom dwellers, and dwarf shrimp.
- Tank level
- Middle
Window to the official scientific data of the species
Scientific Parameters & Models
- Trophic level
- 3.3 ± 0.4 se
- Resilience
- High (less than 15 months)
- Phylogenetic uniqueness (PD50)
- 0.5312
- Bayesian Length-Weight
- a = 0.01995, b = 3.01
Image gallery
Licensed images linked to the species or, when marked, to the closest representative taxon.
Related species
Recommendations grouped by close relatives, companion choices, and similar care.
Variants and close relatives
Same atlas type, nearby scientific identity, genus, or family.
Recommended companions
Compatible cards from coherent ecosystems with matching parameters.
Similar care
Cards with similar requirements, difficulty, habitat, and husbandry profile.















































