Fish Species Profile: Black Ruby Barb (Purple-Headed Barb)

Puntius nigrofasciatus - Black Ruby Barb

The black ruby barb is a tranquil, lovely little barb found in Sri Lanka's wooded streams, off the southern coast of India. It's best described as a nice omnivore tank companion, although it may face competition from larger, carnivorous fish. Both deforestation and over-collection have put this species at risk in the wild.

Species Overview

COMMON NAMES: Purple-headed barb, purplehead barb, ruby barb, black barb

SCIENTIFIC NAME: Pethia nigrofasciata

ADULT SIZE:  2 inches



Family Cyprinidae
Origin Sri Lanka
Social Peaceful
Tank Level Bottom
Minimum Tank Size 30 gallon
Diet Filamentous algae and detritus
Breeding Egg-scatterer
Care Easy
pH 6.0 to 6.5
Hardness 5 to 12 dGH
Temperature 72 to 79 F (22 to 26 C)

Origin and Distribution

The ruby barb is native to Sri Lanka, where it was previously abundant in the upper altitudes of the Kelani and Niwala river basins' forest streams. This natural environment is densely forested with slow-moving waterways that are cooler than those found in many tropical locations. The riverbeds are made of sand or fine gravel, and the water in these streams is soft and acidic.

Unfortunately, over-fishing by people selling these fish for export in the aquarium trade has severely depleted populations. Rapid deforestation has also obliterated much of this lovely fish's native habitat. They were formerly on the verge of extinction, but the International Union for Conservation of Nature now classifies them as vulnerable (IUCN). They will only survive as a viable population in the wild if adequate conservation practices are used.

The export of wild-caught ruby barbs from Sri Lanka will be forbidden starting in 2020. All aquarium specimens are professionally bred, either in Sri Lanka or in one of the other nations that commercially raise aquarium fish. In comparison to wild fish, commercial breeding has resulted in the emergence of a diversity of novel hues and fin morphs.

Colors and Markings

The ruby barb shares the same body shape as other banded barbs, such as the tiger barb, with a pointed head, high back, and deep body. Vertically, three large black stripes go through the body. The body color of young fish ranges from pale yellow to yellow-gray. The head of the fish turns purple-red as it develops. When males reach breeding age, their entire body turns a bright crimson hue.

When both sexes are worried, afraid, or suffering from an illness or bad treatment, they will turn pale. It's very uncommon for fish at pet stores to seem washed out, but when transferred to a quieter setting in a home tank, they reclaim their vibrant colors. Barbels, which are feelers near the mouth or nasal cavity in other barbs, are absent in this species.


Ruby barbs are schooling fish, so keep them in groups of eight or more at all times. They are less aggressive than tiger barbs and may be kept in aquariums with other peaceful fish. Ruby barbs may be maintained securely alongside tetras, other barbs, danios, catfish, and gouramis. make excellent tank companions. With schools of other vertically striped barbs, such as tiger barbs, ruby barbs provide a wonderful visual contrast.

Black Ruby Barb Habitat and Care

The ruby barb can be found in the wild in the cooler, slower-moving forest streams that are shrouded by dense vegetation. The stream bottom is sandy with a coating of mulm, and the water is soft and acidic (organic detritus). It's excellent to recreate these circumstances in the aquarium.

Maintain a temperature of 72 to 79 degrees Fahrenheit in the water, and utilize floating plants to dim the illumination. For the substrate, use sand or tiny gravel in a deeper hue. Although a live-planted aquarium is desirable, fake plants can suffice. There should be lots of open room for swimming as well as hiding spots. If there are no hiding places to make Ruby barbs feel safe, they will turn pale and timid.

Black Ruby Barb Diet and Feeding

Benthic feeders, or bottom feeders, are ruby barbs. They search among the trash that accumulates at the bottom of the woodland streams where they reside for fragments of organic material. Their food consists virtually exclusively of debris and algae.

As a result, it's critical to include lots of vegetables in their diet. Flakes strong in vegetable matter, as well as veggies like shelled peas, raw zucchini slices, and blanched lettuce or spinach, are also healthy alternatives.

You can augment their primarily vegetarian diet with occasional feedings of live foods. Bloodworms, daphnia, and brine shrimp are all good choices to feed as a supplement every week or two.

Gender Differences

Adults reach a length of little over two inches, with males being somewhat bigger than females overall. In males, the entire dorsal fin turns dark, but in females, just the base of the dorsal fin turns dark. Males' pelvic and anal fins will be black or red-black as well. These fins will be much lighter in color in females.

The male ruby barb, like many other species, becomes more vividly colored than the female, especially during the breeding season. When a female spawns, she does not change color significantly, and she has a rounder tummy.

Breeding the Black Ruby Barb 

Ruby barbs are egg-scatterers who can be bred in groups or couples. This species frequently consumes its own eggs, thus once the eggs have been placed and fertilized, it must be removed from the spawning tank. The spawning tank's water should be soft, acidic, and between 77 and 82 degrees Fahrenheit. Plants with fine leaves, such as java moss or spawning mops, should be available for the fish to scatter their eggs on. The lighting should be modest.

In addition to their greenery, breeding couples or groups should be conditioned with enough of tiny live meals. If live and brine shrimp are unavailable, frozen and brine shrimp can be used instead. The male's entire body will be covered with strong deep crimson coloring. The female will not change color as she fills with eggs, but she will get fat.

The male spreads his fins and swims around the female in a courting display before spawning. From start to finish, the procedure might take several hours and generate up to 100 eggs. Adult fish should be removed from the aquarium as soon as spawning is completed. Because the eggs and fry are light-sensitive, keep the tank dark.

In around 24 hours, the eggs will hatch, and the fry will be free to swim in another 24 hours. Initially, the fry will be fed infusoria or fine fry chow manufactured commercially. They can be fed freshly hatched brine shrimp after a few days. If the eggs do not hatch, make sure the spawning couple is adequately fed before the next spawning. Many spawning failures are thought to be caused by an insufficient nutrition.

More Pet Fish Species and Further Research

If ruby barbs appeal to you, and you are interested in some compatible fish for your aquarium, read up on:

Check out additional fish species profiles for more information on other  fish.