Harlequin Rasbora
Trigonostigma heteromorpha

Care Level




Reef Compatible


Plant Safe


Max Size

Less than 2"

Minimum Tank Size

10 gallon


Orange, Black, Silver



Water Conditions

72-77° F, KH 6-10, pH 6.0-6.5


General: This smaller, peaceful community species is naturally present in Malaysia, Singapore, and Thailand. The Harlequin Rasbora is well-adapted to a heavily planted, slightly acidic environment. They will look for broad-leaved plants to stick their adhesive eggs on if mature and ready to reproduce.

Fecundity (Reproduction): The Harlequin Rasbora can lay up to 300 eggs per clutch. They apply adhesive eggs to the underside of vegetative matter when environmental conditions are ideal (fairly acidic 5.3 pH, fairly soft 1 to 3 dGH). The fry will swim freely after several days and should start to be fed baby brine shrimp after one week.

Aquarium Diet: Blackworms, brine shrimp, spirulina, and general flakes

Compatibility: The Harlequin Rasbora is compatible with a large variety of aquarium species: other Rasbora, Danio, Tetra, and Corydoras are common tank-mates. Livebearers are also typically compatible with Rasbora. Although they prefer slightly different water chemistries, Rasbora can typically be kept with livebearers.

Preferred Water Chemistry: Slightly acidic (5.5 to 7.5 pH), soft water hardness (1 to 15 dGH)

Dimorphism: The male Harlequin Rasbora will have a more rounded, elongated triangular pattern, and be thinner in appearance than female Trigonostigma heteromorpha.

Harlequin Rasbora Photo Gallery