Harlequin Rasbora

Harlequin Rasbora (Trigonostigma heteromorpha)

The Harlequin Rasbora is a classic freshwater schooling fish prized for its striking copper-orange coloration, distinctive black triangular marking, and peaceful temperament. Native to the slow-moving streams and peat swamps of Southeast Asia, this elegant species has been a favorite among aquarists for decades due to its beauty, hardiness, and compatibility with a wide range of community fish.

Known for their calm nature and synchronized schooling behavior, Harlequin Rasboras thrive when kept in groups of six or more. They are most comfortable in planted aquariums with open swimming areas, driftwood, and subdued lighting that mimics their natural habitat. Their warm coloration and bold black markings create a beautiful contrast against green plants, making them a standout addition to both community and aquascaped aquariums.

Harlequin Rasboras are exceptionally hardy and easy to care for, making them an ideal choice for both beginner and experienced hobbyists. Their peaceful disposition allows them to coexist with a variety of small, non-aggressive species, while their active schooling behavior brings constant movement and life to the aquarium.

Quick Facts:

• Scientific Name: Trigonostigma heteromorpha
  
• Common Name: Harlequin Rasbora
  
• Adult Size: 1.5–2 inches (4–5 cm)
  
• Temperament: Peaceful
  
• Difficulty Level: Easy
  
• Temperature: 72–82°F (22–28°C)
  
• pH: 6.0–7.5
  
• Diet: Omnivore (flakes, micro pellets, frozen and live foods)
  
• Minimum Tank Size: 10 gallons

With their beautiful copper coloration, graceful schooling behavior, and peaceful nature, Harlequin Rasboras are an excellent choice for hobbyists looking to add timeless beauty and activity to a planted or community aquarium.