Ruby Barb
Ruby Barb

Ruby Barb– Puntius nigrofasciatus

Ruby Barb
ruby barb
Ruby Barb - Pictures by


The Ruby Barb, a small and lively fish belonging to the minnow family, was earlier considered a barb of the genus Barbus and you may therefore find it described under the name Barbus nigrofasciatus in older literature. It is today considered a part of the genus Puntius; hence the scientific name Puntius nigrofasciatus.

Puntius nigrofasciatus is known under several different common names, including Ruby Barb, Black Ruby Barb, Purple-Headed Barb, and Purplehead Barb.

The Ruby Barn is considered moderately difficult to care for and is not recommended for novice aquarists.

The expected lifespan of a Ruby Barb is 3-5 years.

Puntius nigrofasciatus is listed as Conservation Dependent on the IUCN Red List of Threatened Species. It was listed as Vulnerable from 1986 until it was moved down to just Conservation Dependent in 1996.


Kingdom:      Animalia
Phylum:         Chordata
Class:            Actinopterygii
Order:           Cypriniformes
Family:          Cyprinidae
Genus:           Puntius
Species:         Puntius nigrofasciatus

Geographical range, habitat and habits

The Ruby Barb lives in southern Sri Lanka in Asia where it can be found in forested streams from the Kelani basin to the Nilwala basin. It inhabits densely grown and fairly slowly flowing hilly streams at an elevation of approximately 300 metres (1000 feet). These regions are tropical but the shaded streams are comparatively cold: XX–79 °F / 20–26 °C. The water stays in the lower part of the temperature range during the winter and increases during the summer. The water is acidic (pH 6.0-6.5) and has a hardness of 5-12 dGH. The substrate is gravel or sand. In the wild, the Ruby Barb chiefly feeds on filamentous algae and detritus. 

Size and appearance

The largest scientifically measured Ruby Barb was 6.0 cm (2.4 in). The Ruby Barb has the typically high-backed Barb shape. The male fish is silvery or dark blue to black with a crimson head, while the female displays duller colours and dark vertical bars. The basal part of all the vertical fins is deep black in females, while pelvic fins are reddish and the anal fin blackish red in males. (His dorsal fin is deep black.)

Young Ruby Barbs are of a yellowish gray shade and sport vertical striping.

Ruby Barb care

The Ruby Barb is a lively schooling fish and you need to get a group of at least six specimens, preferably more, if you wish to keep this species. A school is needed for this fish to stay happy, healthy and friendly in the aquarium. Always keep more females than males; a 3:1 ratio is good. The aquarium where you keep a school of Ruby Barbs should be at least 70 cm long. The fish will spend most of their time in mid water. Unlike the Tiger Barb, the Ruby Barb is not a fin-nipper. The Ruby Barb is known to sometimes school with striped barbs.

Ideally include areas of densely grown plants in the set up while also leaving space open for swimming. Subdued lighting is recommended, you can for instance use floating plants to dim the light. The Ruby Barb likes to be sheltered from the surface.

Ruby Barbs can become exceedingly shy if they are

  1. kept in aquariums without enough hiding spots
  2. kept alone or in a very small group (<6 specimens)
  3. kept in a brightly lit aquarium where there are no plants to seek shelter under

As mentioned above, the Ruby Barb is used to 20-22º C (68-72º F) during the winter and 22-26º C (72-79º F) during the summer. The water hardness in its native home is normally 5-12 dGH, but this fish is known to adapt to hardness up to 15 dGH. Keep the water acidic; ideally in the 6.0-6.5 range. Let a layer of humus stay on the bottom over the substrate (sand or gravel). Keep the levels of organic waste low.

Feeding Ruby Barb

In the wild, the Ruby Barb chiefly feeds on filamentous algae and detritus. This doesn’t mean that it will turn down a meaty threat in the aquarium, but it should not be kept on a diet rich in protein and low in fibre. The Ruby Barb accepts most types of food, from small live animals to pellets, flakes and blanched greens (lettuce, zucchini, spinach, and so on). It may nibble on plants in the aquarium but will usually cause no harm. Keeping your Ruby Barbs on a varied diet will boost their immune system and is therefore recommended.

Breeding Ruby Barb

The male Ruby Barb is leaner, larger and taller, and his colours are darker and more intense than those displayed by the female. Sexing this species is therefore not very hard. During the breeding period, the male fish will enhance his colours (see section about appearance above). Sometimes when males are kept together in a group in aquariums they will retain their intense breeding colours outside the breeding period. Exactly why they do that remains a mystery, but it may be a form of competition. 

The Ruby Barb is aquarium bred in fairly large quantities from the aquarium trade. If you wish to breed Ruby Barbs, keep the water temperature in the 25-28º C (77-82º F) range, the water hardness below 12 dGH, and the pH-level around 6.0.

During courtship, the male Ruby Barbs will swim around and display in front of the females. The spawning usually takes place in the morning among fine leafed plants or among the roots of floating ones. This is an egg scattering species and the female will release over 100 eggs among the plants. The spawning can proceed for up to two hours. When it’s over, professional breeders usually remove the adult fish to prevent the eggs from being eaten. This species does not care for eggs or fry. You can expect the eggs to hatch within 24-48 hours.

If the eggs do not become fertilized, the reason can be the male fish not being kept on a varied and nutritious diet.