Rasbora | Rasbora heteromorpha
Cyprinds / Rasboras / Rasbora
Profile: Rasbora, Harlequin Fish
Rasbora heteromorpha Synonyms: None
Physical description: An elongated species with a long caudal peduncle. The body coloration is pinkish silver with a violet iridescence. The belly is more white in color and the fins have a pink to red tinge. On the rear half of the body is a characteristic, black wedge-shape. The area on the caudal peduncle is redder than the rest of the fish. The outer rays of the caudal fin are red.
Size/Length: To 1.75" (4.5 cm)
Similar species: Espes Rasbora ( Rasbora espei ), Hengel's or Slender Rasbora ( Rasbora hengeli )
Habitat: Still and slow-moving brooks and swamps, in shallow areas. Southeast Asia; Malay Peninsula, Sumatra, Thailand.
S: middle, top
Aquarium: A tank measuring 20" (51 cm) with a volume of 10 gallons (38 L). Use a dark gravel substrate and a partial cover of floating plants. Use dense planting along the edges and sides of the tank. Provide hiding places in these thickets of plants, and in wood and roots.
Water chemistry: pH 5-7.5 (6.0), dH 1-10 dH (4), 72-79°F (22-26°C)
Social behavior: A peaceful, schooling fish that should be kept in groups of six or more. Combine this species with other small to medium sized, schooling fish.
Suggested companions: Rasboras, Coolie Loaches, Corydoras, Loricarids, Apistogramma , tetras, hatchetfish, Colisa.
FOOD: Live; insects, insect larvae, crustaceans, Tubifex ; flakes.
Sexual differences: The wedge-shape of males is sharper and more pointed, while the female's is less clearly defined. Males are also more slender.
Breeding techniques: Use water with a pH from 5.3-5.7, a water hardness from 1-3 dH, and a temperature from 79-82°F (26-28°C). Plant the tank heavily with broad leafed plants (Amazon Swords, Cryptocoryne ). The water level should be lowered to 5-8" (13-20 cm) and the water can be peat filtered. Conditions the pair separately for a period of one to two weeks prior to the intended spawning time. Spawning may be triggered by the rising of the sun. The spawning process takes two to three hours, during which as many as 250 eggs are deposited on the underside of leaves. The parents should be removed just after spawning. Place dark paper on four sides of the tank so the eggs will not be as susceptible to fungus. The eggs hatch after 24 hours and are free-swimming 3-4 days later. Start feeding with liquid foods, Infusoria, and egg yolk. After 2-3 days more, the fry can be fed with Artemia nauplii. The young very sensitive to new water, so small water changes should be made several times weekly. The fry grow quickly.
Breeding potential: 7. Breeding under the right conditions is moderately difficult, although the fry are difficult to rear.
Remarks: When attempting to spawn this species, only females of about 10-20 months should be used as often older females will not spawn.
Difficulty of care: 3. A robust species recommended for community tanks.