Max Size: 9 - 12cm

Mascara Barb (Dawkinsia Assimilis)

Mascara Barbs, Dawkinsia Assimilis, make excellent members of a community aquarium because they are relatively peaceful. Even though these barbs do not nip fins of other fish, they are boisterous, especially the males, when engaging in chases; therefore, you should not keep smaller, more timid species with them.

In the aquarium, Mascara Barbs do best with equally large and active tankmates as they are fast-moving, aggressive feeders. It would be ideal for these Barbs to live with other Cyprinids such as Denison Barbs (found in the wild with Mascara Barbs) and other medium to large-sized Barbs as well as Rainbowfish, Gouramis, and Loaches.

As a natural schooling species, mascara barbs should be kept in groups of eight or more. The more barbs you keep in the aquarium, the less nervous your fish will be and the more natural and effective your display will look. The males will also focus on maintaining their position within the group if they are kept in larger groups, which will restrict aggression between them.

A good aquarium setup for Mascara Barbs would include rocks of varying sizes, pebbles, sand or fine gravel, and perhaps some small boulders as a substrate. Your fish would also benefit from driftwood and hardy aquatic plants such as Anubias or Microsorum.

They are named for their pink blush coloration around their noses and their blue-black lines under their eyes. There is a pear-shaped black spot on the caudal peduncle of these silvery fish. The body also has a curved reddish-pink line that resembles a thin pearl necklace. The majority of their fins are translucent except for their caudal fin, which has red and black tips, and their dorsal fin, which is bright red.

Mascara Barb (Dawkinsia Assimilis) Video

Mascara Barbs - Dawkinsia Assimilis


Mascara Barbs
Dawkinsia assimilis
Mascara barbs
Mascara Barb
Mascara Barb
Quick Facts
Scientific NameDawkinsia Assimilis
Year Described1849
Other NamesRed Necklace Barb, Assimilis Barb
Aquarium LevelMiddle - Top
DifficultyBeginner - Intermediate
Best kept asGroups 8+
Lifespan8 - 10 years
Water Parameters
Water TypeFreshwater
PH6.0 - 8.0
GH5 - 15
KH1 - 10
TDS40 - 70
65 - 80℉
18 - 27℃

Natural Habitat

Chalakudy River
Kallada River


In the home aquarium, the Mascara Barb will readily accept most good quality dried foods such as granules, flakes and sinking pellets. These modern food products have been developed to provide all adequate nutrition to maintain your fish's health and dietary requirements.

Providing additional foodstuffs such as live, frozen, and freeze-dried meals such as bloodworm, daphnia, and tubifex once or twice a week will provide additional benefits to your fish's health and well-being but is not a must for this fish.

It should be noted that bloodworms should only be given as an occasional treat and should not be used as the staple diet as they are difficult for fish to digest and can potentially cause blockages.

This fish is an omnivore in the wild, meaning it will consume some vegetable matter. Although most modern fish foods take this into account and include them in their products, you can still supplement your fish's diet with blanched vegetables such as spinach, broccoli, and zucchini. Ensure you do not overfeed your fish and remove any leftovers the following day.

Tank Mates

10 interesting tank mate ideas for the Mascara Barb could include:

Blue Spotted Hill Trout(Barilius bakeri)
Borneo Red Fin Silver Shark(Cyclocheilichthys janthochir)
Bristlenose Pleco(Ancistrus Cirrhosus)
Colombian Redfin Tetra(Hyphessobrycon columbianus)
Denison Barb(Sahyadria denisonii)
Flame Tetra(Hyphessobrycon flammeus)
Flash Plecostomus(Panaqolus albivermis)
Red Tailed Black Shark(Epalzeorhynchos bicolor)
Rohani Barb(Dawkinsia Rohani)
Silver Flying Fox(Crossocheilus reticulatus)

Sexual Dimorphism

Both sexes will display impressive red colouration as mature adults, making it difficult to distinguish between the male and female Mascara Barbs. Males, however, have a more striking colour pattern and develop vivid red dorsal fins and detailed dorsal filaments. In addition, their heads will be covered with tubercules when they are breeding. Conversely, females tend to grow larger, heavier, and duller as they age.

Frequently asked questions

Are Mascara Barbs a schooling or shoaling species?

Mascara Barbs are a schooling species in nature; therefore, you should ideally keep these fish in groups of 8 or more individuals. Maintaining these Barbs in suitable numbers will not only make your fish less nervous but will also result in a more natural and effective looking display. In addition, keeping this species in larger groups will usually restrict any aggression because the males will be concentrating on maintaining their hierarchical position within the group.

How big do Mascara Barbs grow?

Mascara Barbs are one of the larger barb species kept by aquarists, growing up to 9-12cm in length.

How do you sex Mascara Barbs?

It can be relatively challenging to distinguish male from female Mascara barbs as both sexes will show impressive red colouration as mature adults. However, males will typically have a more intense colour pattern and develop detailed dorsal filaments and vivid red dorsal fins and, when in breeding condition, will display noticeable tubercules on their heads. In contrast, adult females usually grow a little larger, are heavier-bodied, and less colourful than males.

What are the ideal tankmates for Mascara Barbs?

Seeing as Mascara Barbs are fast-moving, aggressive feeders, it would be better to keep them with equally large and active tankmates in the aquarium. Ideal tankmates for these Barbs would be other schooling or shoaling Cyprinids such as medium to large-sized Barbs, larger Rainbowfish, Gouramis, Botiids, Cobitids, Nemacheilids, and Balitorid Loaches.

What do Mascara Barbs look like?

Mascara Barbs have a pinky-red colouration around their snout and a blue-black line under their eyes hence their name. These fish have silvery colour bodies and display a tear-shaped black spot on the caudal peduncle. You will also notice a curved line throughout the body that almost looks like a small pearl necklace-type pattern. Most of their fins are transparent except for their tailfin with red and black tips, and their dorsal fin is a bright red colour.

What is the origin of the Mascara Barbs?

Mascara Barbs are endemic to Kerala and Karnataka in the Southwest Indian states, where they occur in the Chalakudy, Kallada and Netravati river basins. Mascara Barbs have various habitat types depending on location and the time of year. For example, in the Netravati, they were reported in limited zones with a sluggish, almost still flow and muddy substrate. In contrast, people collected the Chalakudy fish from rocky, clear, flowing stretches between waterfalls formed from the river descending from the Western Ghats mountains.

What should I feed my Mascara Barbs?

In captivity, Mascara Barbs are not picky and are easily fed. However, you should provide your Barbs with a balanced diet comprising of regular meals of small frozen and live foods such as daphnia, brine shrimp, bloodworms, and such alongside high quality dried flakes and granules. This mix will promote the most favourable condition and colours.

Other Barbs of interest

African Banded Barb(Barbus fasciolatus)
Arulius Barb(Dawkinsia arulius, Puntius arulius)
Black Ruby Barb(Pethia nigrofasciata)
Blue Spotted Hill Trout(Barilius bakeri)
Borneo Red Fin Silver Shark(Cyclocheilichthys janthochir)
Butterfly Barb(Barbus hulstaerti)
View all Barbs
Date Added: 14/05/2020 - Updated: 12/08/2022 11:25:51