Mascara Barb Care Guide - Aquarium Setup, Diet & Breeding

The Mascara Barb, Dawkinsia assimilis, is a lively Sri Lankan cyprinid with the streamlined shape typical of a fast-water barb. Its silvery to golden body is marked by darker vertical patterning, while mature fish can develop richer gold, red and black tones, especially during courtship and spawning.

This species is an active shoaling fish that spends much of its time in open water. Groups establish a loose social hierarchy, with males displaying to one another and competing for the attention of females without usually causing serious injury when they have adequate space.

In the wild, Mascara Barbs inhabit clear streams and rivers with rocky or gravelly bottoms, submerged branches and patches of aquatic or marginal vegetation. Seasonal changes in flow and water level shape these habitats, and the fish are adapted to well-oxygenated water and regular movement.

Dawkinsia assimilis was formerly placed in the broader Puntius group, but modern classification places it in Dawkinsia, a genus containing several attractive barbs from Sri Lanka and southern India. It remains less commonly encountered than some of the better-known aquarium barbs, making it an appealing choice for keepers interested in unusual Asian shoaling fish.

Mascara Barbs are native to Sri Lanka in South Asia, where they occur in river systems and clear, flowing streams, particularly in the island’s wetter regions. They are associated with upland and forested waterways rather than stagnant ponds.

A group should have at least 180 litres, with a preferred footprint of around 120 cm by 45 cm or larger because this is an active, open-water species. Use strong, reliable filtration and good oxygenation with moderate water movement, leaving a generous swimming area across the front and centre of the aquarium. A fine gravel or sand substrate, smooth stones, driftwood and hardy plants around the edges create a natural stream-like layout; secure plants well and avoid sharp decor. A tight-fitting cover is advisable because active barbs can jump.

Mascara Barbs can reach about 15 cm (6 in) in total length. Females are usually the larger and deeper-bodied sex, while males are generally a little smaller and more slender.

Mascara Barbs are omnivorous opportunists. Offer a varied diet based on quality flakes or small pellets, supplemented with frozen or live foods such as brine shrimp, bloodworms, daphnia and mosquito larvae. Regular portions of blanched spinach, shelled peas or other soft vegetable matter help provide balance, while occasional live foods encourage natural foraging and spawning behaviour.

Mascara Barbs are generally suitable for a spacious community aquarium when kept in a proper group. Good companions include similarly sized peaceful barbs, danios, larger rasboras, rainbowfish, peaceful loaches and robust Corydoras or other community catfish. Their energetic nature can unsettle very timid species, and they may nip slow-moving, long-finned fish if kept in too small a group or confined space. Avoid combining them with bettas, fancy guppies and other delicate long-finned fish, as well as aggressive cichlids or fish small enough to be swallowed.

Mascara Barbs are egg-scattering spawners that can be bred in a separate, mature aquarium with gentle flow, fine-leaved plants or spawning mops, and slightly softer, clean water. Condition a group with plenty of live or frozen foods, then introduce the adults when females are full of eggs. Spawning usually takes place among vegetation, after which the adults should be removed because they may eat the eggs. The eggs hatch in roughly one to two days, and the free-swimming fry can initially be fed infusoria or other suitably tiny foods before moving on to newly hatched brine shrimp.

Mature females are typically fuller-bodied and less intensely coloured, especially when carrying eggs. Males are usually slimmer and develop stronger gold, red and black breeding colours, with more pronounced colour displays during courtship.