Harlequin Rasbora
Trigonostigma heteromorpha

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.

Dimorphism: The male harlequin rasbora will have a more rounded, elongated triangular pattern, and be thinner in appearance than female.

Fecundity: 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 6.0 pH and soft water). After spawning has occurred it is recommended to remove the adults to increase the yield of the fry. The fry will swim freely after several days and should at first be fed infusoria. As the harlequin rasbora fry grow larger, they can be switched to live baby brine shrimp.

Water Chemistry: 72-77° F, KH 6-10, pH 6.0-6.5

Aquarium Diet: Harlequin rasboras are omnivores and will accept blackworms, brine shrimp, spirulina flakes, and general fish flakes.

Compatibility: The harlequin rasbora is compatible with a large variety of aquarium species including other rasboras such as the brilliant rasbora (Rasbora einthovenii), danios such as the pearl danio (Danio albolineatus), tetras such as the candy cane tetra (Hyphessobrycon bentosi) or pristella tetra (Pristella maxillaris), and Corydoras species. Livebearers such as platies (Xiphophorus variatus) and swordtails (Xiphophorus hellerii) are also typically compatible with harlequin rasboras, although they prefer slightly different water chemistries.