Harlequin Rasbora

Care

Harlequin Rasboras are a beautiful, peaceful shoaling species suitable for the community aquarium. They should be kept in groups of at least 6 fish, and preferably more; in the wild, this species moves around in groups of 100+ fish. The aquarium should be well-planted to provide a network of hiding places and much appreciated shady areas. Although this species will acclimatise to a wide range of water conditions, they will be seen at their best in soft, acidic water which mimics their natural environment. Peat filtration is suggested. Similar-looking species are often available in the trade - Trigonostigma espei and T. hengeli have now been joined by the recently described T. truncata from southern Thailand. Aquarium-bred ‘black’ and ‘gold’ strains of Harlequin Rasbora are also sometimes available.

Feeding

Flake, micropellets, small frozen foods such as mosquito larvae, brineshrimp and daphnia.

Breeding

Fairly difficult. A separate shallow breeding aquarium should be set up with extremely soft water (dh: 1-3 degrees) and with a pH around 5.5 – again, peat filtration is suggested. A good amount of broad-leaved plants should be added which will be used by the fish for depositing eggs. Spawning is often triggered by the first rays of morning sun, and up to 250 eggs will be deposited on the underside of the plant leaves. The parents should be removed as soon as spawning has ceased, otherwise they will predate on the eggs. The eggs are light-sensitive, so it is important that the sides of the tank are covered in order to keep the tank in darkness and prevent the eggs from fungussing. After 24 hours, the eggs will hatch, and after a further 72 hours, the wrigglers will become free-swimming. The tiny fry will require very small foods, starting with infusoria, and gradually moving on to bigger foodstuffs as they grow. Small frequent partial water changes should be carried out with much care as the fry are incredibly sensitive to changes. If your fish fail to breed, try with a younger female, as sometimes older females are unable to spawn.