Rosy barb

Water parameters

Tolerated range for this species. Aim for the middle of each band rather than the extremes.

Tank and habitat

Substrate: any.

Behavior

Plant interaction: may nibble soft.

Feeding

Omnivore that eats everything. Flake, pellets, frozen bloodworm, frozen brine shrimp, frozen daphnia, blanched vegetables (peas, zucchini, spinach), algae wafers, and live food. They graze on algae in addition to accepting prepared foods. Feed twice daily. The rosy-red coloring in males improves with carotenoid-rich foods (brine shrimp, krill, spirulina). Overfeeding is easy because they eat relentlessly; moderate portions keep them fit.

Compatibility

• Hardy, active schooling barb. Peaceful by barb standards; minimal nipping behavior. Works with most medium-sized community fish.
• Groups of 6+ bring out the best coloring and behavior. Males in breeding condition turn deep red-pink and compete for female attention with fin displays.
• Tolerates cooler water (16–25°C), making them one of the few tropical barbs suitable for unheated tanks in temperate climates. Good companions for goldfish (in large enough tanks), white clouds, and other subtropical species.
• Larger than many common barbs at 10–14 cm for mature adults. They need more space than their juvenile size suggests. A group of adults needs 150 L.

Origin and habitat

Pethia conchonius, the rosy barb, is a hardy, active barb from southern Asia, native across Afghanistan, Pakistan, India, Nepal, and Bangladesh, with the original specimens coming from northeastern Bengal and the Kosi and Ami rivers. Hamilton described it in 1822, and the species sat in Barbus and then Puntius before Pethiyagoda and colleagues placed it in Pethia in their 2012 review of South Asian barbs. It lives in lakes and brisk hill streams in a subtropical climate, and records put its temperature range around 18 to 22 C, which makes it one of the few barbs comfortable in an unheated or lightly heated tank. Breeding males flush a deep rosy red, leaner and far brighter than the duller, rounder, silver-pink females, and that red is what names the fish. Maximum size is about 14 cm, reached by wild fish, while aquarium specimens usually stay much smaller, around 5 to 8 cm. All trade fish are commercially bred and selected for colour, and the species has been introduced and become established in waters well outside its range. IUCN lists it as Least Concern.

Breeding

An easy, prolific egg scatterer and a good first breeding project. Conditioning the sexes separately on rich food and then putting them together over fine-leaved plants or a spawning mop sets things off, usually in the morning, and water chemistry is not fussy. A spawning female scatters a couple of hundred semi-adhesive eggs over the plants and substrate, the adults eat them readily so they should be removed, and the eggs hatch in a little over a day. The fry are free-swimming within a couple of days and take baby brine shrimp, growing quickly. Rosy barbs are farmed in huge numbers in outdoor ponds.

Common problems

The usual surprise is size: the small juvenile in the shop becomes a much larger, very active adult, so a group needs a proper mid-sized tank with swimming room rather than a nano. Beyond that the fish is about as hardy as any in the hobby, rarely sick and tolerant of a wide range of water and treatments, with ich only a risk on badly stressed new fish. The main cosmetic point is that males show their full rosy red only in breeding condition or when competing in a mixed group; a lone male or one out of condition can look a plain olive-gold. As active fish they can also nip, so they suit a proper school and robust tankmates rather than slow, long-finned ones.

Outdoor pond suitability

Climate

subtropical

USDA zones

8–12 (winter low around -12°C or warmer)

Outdoor pond at least 60 cm deep for thermal mass. Local frost depth and surface freezing matter.

Bioload

Further reading

• How to cycle a fish tank
• Stocking ideas by tank size