HARLEQUIN RASBORA (Trigonostigma heteromorpha)
$6.20
Full Description
Here’s a complete care guide for the Harlequin Rasbora (Trigonostigma heteromorpha)—a beautiful, hardy, and peaceful freshwater fish that’s perfect for community tanks and planted aquascapes.
Harlequin Rasbora Care Guide
Scientific Name: Trigonostigma heteromorpha
Common Name: Harlequin Rasbora
Origin: Southeast Asia (Thailand, Malaysia, Sumatra, Singapore)
Size: 1.5–2 inches (3.8–5 cm)
Lifespan: 5–8 years
Temperament: Peaceful and social
Reef Safe: ❌ (freshwater species)
Tank Level: Mid to upper water column
Schooling Fish: ✅ Yes (should be kept in groups of 6+)
️ Tank Requirements
| Requirement | Recommendation |
|---|---|
| Tank Size | 10+ gallons (20+ recommended for groups) |
| Group Size | Minimum of 6 (preferably 10+) |
| Aquascape | Heavily planted tank with open swimming space |
| Substrate | Dark sand or fine gravel enhances coloration |
| Lighting | Low to moderate (mimics natural conditions) |
| Tank Lid | Recommended (they can jump) |
Harlequin Rasboras feel most secure and display best color in groups and planted setups with gentle lighting.
Water Parameters
| Parameter | Ideal Range |
|---|---|
| Temperature | 72–80°F (22–27°C) |
| pH | 6.0–7.5 (slightly acidic preferred) |
| Hardness | 2–12 dGH |
| Ammonia/Nitrite | 0 ppm |
| Nitrate | < 20 ppm |
✅ Naturally found in soft, slightly acidic waters, but they are adaptable.
️ Diet & Feeding
Harlequin Rasboras are omnivorous and easy to feed. A varied diet helps enhance their color and energy.
Feed:
-
High-quality micro flakes or nano pellets
-
Live or frozen daphnia, brine shrimp, bloodworms
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Crushed vegetables (occasional treat)
-
Spirulina-based foods for plant content
Feeding frequency: 1–2 times daily in small portions they can consume in under 2 minutes.
Temperament & Tankmates
| Trait | Description |
|---|---|
| Behavior | Calm, non-aggressive, shoaling |
| Tankmates | Tetras, Corydoras, peaceful Gouramis, small barbs |
| Avoid | Large or aggressive fish (e.g., cichlids, large barbs) |
Harlequins school tightly when stressed, but spread out and interact beautifully when comfortable.
Sexing & Breeding
| Gender | Description |
|---|---|
| Male | Slimmer body, more intense orange-red coloring |
| Female | Rounder body, especially when carrying eggs |
Breeding Tips:
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Use a separate breeding tank with soft, acidic water (pH ~6.0–6.5)
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Provide broad-leaved plants or spawning mops
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Eggs are scattered underneath leaves
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Adults should be removed after spawning—they will eat eggs
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Eggs hatch in ~24 hours; fry swim freely in 3–5 days
-
Feed fry infusoria, then baby brine shrimp
✅ Pros & Cons
| Pros | Cons |
|---|---|
| Peaceful and beginner-friendly | Must be kept in schools (6+) |
| Beautiful coloration and active | Can fade in color if stressed |
| Compatible with most community fish | Small—can be eaten by large tankmates |
| Easy to feed and hardy | Eggs and fry need protection when breeding |
Final Verdict
Harlequin Rasboras are one of the best community fish for planted aquariums. Their peaceful nature, attractive appearance, and hardy disposition make them ideal for both beginners and experienced aquarists.
6 in stock