Cyprinidae

Harlequin rasbora

Trigonostigma heteromorpha

Fish Reaching Five Centimeters in Indonesian Waters

• Black
• Tropical
• Regional distribution
• Freshwater fish
• Southeast Asia
• Compressed cross-section
• Small
• Tropical fish

The harlequin rasbora (Trigonostigma heteromorpha) is a small fish in the family Cyprinidae. The species became an instant favorite among aquarists after its introduction in the early 1900s and is the best known and most widely kept species among the rasboras. In 1935, an image of a trio of harlequin rasboras, stamped in 14k gold, graced the cover of the first edition of William T. Innes's classic Exotic Aquarium Fishes, and remained through all 19 editions.