đļ Harlequin Rasbora (Trigonostigma heteromorpha)
The Harlequin Rasbora is one of the most popular and recognizable schooling fish in the hobby. Their distinctive black triangular patch and copper-colored body make them instantly identifiable. Hardy, peaceful, and beautiful, harlequins are perfect for community tanks and one of the best choices for beginners wanting a schooling fish.
đ Quick Facts
| Scientific Name | Trigonostigma heteromorpha |
|---|---|
| Adult Size | 2 inches (5 cm) |
| Minimum Tank | 10 gallons (38 liters) |
| Temperament | Peaceful, schooling |
| Difficulty | Beginner |
| Lifespan | 5-8 years |
| Origin | Southeast Asia (Malaysia, Thailand) |
â ī¸ Important Considerations
- Must be kept in groups - Minimum 6, prefer 10+
- Peaceful fish - Don't keep with aggressive species
- Prefer soft, slightly acidic water - But adaptable
- Mid-water swimmers - Need open swimming space
đ Tank Requirements
- Tank Size: 10 gallons for 6, larger for bigger schools
- Plants: Appreciate planted tanks
- Open swimming: Need space in middle level
- Lighting: Moderate - shows off colors well
Water Parameters
| Temperature | 72-81°F (22-27°C) |
|---|---|
| pH | 6.0-7.5 |
| Hardness | 2-15 dGH |
| Ammonia/Nitrite | 0 ppm |
| Nitrate | <20 ppm |
đŊī¸ Diet & Feeding
Omnivores that accept most foods readily.
- High-quality flakes - Staple
- Micro pellets
- Frozen daphnia
- Frozen brine shrimp
- Frozen bloodworms - Occasional
Feed small amounts 2-3 times daily.
đ Compatibility
Good Tankmates
- Tetras (Neon, Cardinal, Ember)
- Other rasboras
- Corydoras
- Small peaceful barbs
- Dwarf Gouramis
- Bettas (usually peaceful)
- Shrimp and snails
Avoid
- Large predatory fish
- Aggressive cichlids
- Very active/boisterous fish
đĢ Schooling Behavior
- Keep in groups of 6 minimum, 10+ ideal
- Larger schools = more natural behavior
- Will school tightly when threatened
- Spread out when comfortable
- Males may display to females
đĄ Tips for Success
- Keep in larger schools for best behavior
- Provide plants around edges with open center
- Stable water parameters more important than perfect values
- Great community fish for beginners
- Variety in diet enhances colors
đ Summary
Harlequin Rasboras are ideal community fish - beautiful, peaceful, hardy, and active. Their distinctive markings and tight schooling behavior make them a pleasure to watch. Keep them in groups of 10 or more for the most impressive display, and they'll thrive for many years in a well-maintained community tank.