Harlequin Rasbora

Scientific Name(s): Trigonostigma heteromorpha

Synonyms: Rasbora heteromorpha

Common Name(s): harlequin rasbora, harlequin fish, pork (lamb) chop rasbora

Origin: Southeast Asia

Family: Cyprinidae

Species Type: Minnow

Maximum Size: 1.5" to 2"/4 to 5 cm

Life Span: 6 years

Natural Habitat: Forest streams and rivers of Thailand, Malaysia and Sumatra.

Diet: Small frozen and prepared foods. Small pellets, flake and bloodworm or small shrimp.

Temperature: 73-80° (23°-27° C)

pH: 6.0-7.5

Minimum Tank Size: 10 gallons

Tank Region: Middle to upper portions of the tank.

Temperament: The harlequin rasbora is a very active yet peaceful schooling fish. They do best in a school with a minimum of six fish.

Possible Tank Mates: They do well in community tanks and are compatible with several types of smaller schooling fish with a similar temperament.

Filtration and Setup: No special filtration is required for these fish but their water should be kept very clean. They will do well in a planted tank.

Coloration: The harlequin rasbora can typically be found in three color phases. The most common phase has a copper (orange) coloring with a black triangle (pork chop) shaped marking which covers the rear half of the fish. The male tends to be slightly more brilliant in color than the female and the black marking tends to be more rounded than the female’s marking adjacent to the anal fin. Females are often plumper while the males are more slender. Harlequins can also be found in gold and black color variations. Two very similar species of fish which are sometimes confused with the T. heteromorpha (harlequin) are T. Hengeli and T. espei. T. hengeli is a more slender fish than T. heteromorpha and T. espei has a distinctive yellow stripe at the top of the black marking.

Breeding: Harlequins require soft acidic water (pH between 6.0 to 6.5) for spawning and will not spawn in more alkaline water. The female deposits her eggs on the bottom of broad leaf plants and the male follows behind to fertilize the eggs. Adults should be removed from the tank once the eggs are deposited and fertilized to assure the adults do not eat the eggs or fry.