Max Size: 5cm

Black Ruby Barb (Pethia nigrofasciata)

The Ruby Barb is a gorgeously coloured, peaceful, small fish that is well suited to any community aquarium with many other fish species.

They are hardy and adaptable and show there best colours and their confidence when in the right tank conditions.

This species of barb possess a pointed deep purple-red coloured head, high back, and ruby red body. They have three black bands that run vertically through there body.


Black Ruby Barb
Black Ruby Barbs Spawning
Quick Facts
Scientific NamePethia nigrofasciata
Other NamesPurple-Headed Barb, purple head barb, ruby barb, black barb
OriginsSri Lanka
Aquarium LevelBottom - Middle
Best kept asGroups 5+
Lifespan3 -4 years
Water Parameters
Water TypeFreshwater
PH5.5 - 7.5
GH5 - 12
TDS36 - 268
72 - 79℉
22.2 - 26.1℃


In the home aquarium, the Black Ruby 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

1 interesting tank mate ideas for the Black Ruby Barb could include:

Denison Barb(Sahyadria denisonii)

Sexual Dimorphism

It is easy to recognise a female from a male Black Ruby Barb in several different ways.

The males develop a more intense ruby colour, not only in their bodies by also on their dorsal and anal fins.

The females are much paler, and only the base of their dorsal fin turns black as well as having more rounded bellies, and they grow slightly longer than males.

Frequently asked questions

Are Black Ruby Barbs aggressive?

Black Ruby Barbs generally have a peaceful disposition and can be somewhat shy. Therefore, these fish are best kept in groups of 6 or more individuals. However, these Barbs misbehave in small groups as the stress from being isolated virtually always comes out as aggression towards other tankmates.

How big do Black Ruby Barbs grow?

Black Ruby Barbs can grow up to a maximum length of 8 centimetres, with the female usually being slightly longer than males.

What are the best tankmates for my Black Ruby Barbs?

Black Ruby Barbs have no unique demands in terms of water chemistry; therefore, you can combine them with a majority of popular fish in the aquarium hobby, such as other small Cyprinids as well as Livebearers, Rainbowfish, Tetras, Loaches, Anabantoids and Catfish.

What is the best aquarium set up for my Black Ruby Barbs?

When it comes to Black Ruby Barbs, the choice of decor is not particularly critical; however, these fish seem to display better colouration in a heavily planted aquarium with a dark substrate. Adding some driftwood roots or branches, floating plants, and leaf litter also appears to be appreciated and adds a more natural feel. Strong filtration is not required; however, they seem to enjoy a certain level of water movement and will thrive in a hill stream-type aquarium set-up.

What should you feed Black Ruby Barbs?

In the aquarium, Black Ruby Barbs are unfussy and easily fed. However, suppose you would like the best condition and colours of your fish. In that case, you should offer regular meals of small live and frozen foods such as artemia, bloodworm and daphnia, alongside high quality dried food such as flakes and granules, some of which must include additional plant and algal content.

Where do Black Ruby Barbs originate?

Black Ruby Barbs are endemic to the Nilwala and Kelani river basin alongside other more minor drainages between them in the southwestern islands of Sri Lanka in South Asia. Their natural habitat consists of several small, pristine streams containing clear or slightly stained, shallow water. Not much sun can penetrate the forests floor, so these aquatic habitats are shaded, and the water temperature is usually relatively cool.

Other Barbs of interest

African Banded Barb(Barbus fasciolatus)
Arulius Barb(Dawkinsia arulius, Puntius arulius)
Blue Spotted Hill Trout(Barilius bakeri)
Borneo Red Fin Silver Shark(Cyclocheilichthys janthochir)
Butterfly Barb(Barbus hulstaerti)
Checker Barb(Oliotius oligolepis)
View all Barbs
Date Added: 06/08/2020 - Updated: 05/01/2022 16:10:05