|Genus & Species: Pethia Nigrofasciata|
|Common Names: Black Ruby Barb, Purple-Head Barb, Ruby Barb|
|Temperature: 71.5 – 79ºF (22 – 26ºC)|
|pH: 6.0 – 7.0|
|GH: 5.0 – 12 dGH|
|Max Size: 5.5 – 8 cm (2 – 3 inches) in length|
|Lifespan: 5 years|
|Depth Preference: Bottom dweller & mid dweller|
|Tank Size: 30 gallons|
Black ruby barbs are best known for their use in breeding various hybrids of tiger barbs such as the green tiger barb and the albino tiger barb. When they are young they may display a yellow and grey complexion until they mature.
Origin & Habitat
Black ruby barbs are a freshwater species of fish endemic to mainland India but were likely translocated to Sri Lanka. Five species of Pethia (P. Bandula, P. Nigrofasciata, P. Cumingii, P. Reval, and P. Melanomaculata) are all currently found in small streams running off from the Nilwala and Kelani river basins.
Their natural habitat has an abundance of aquatic plants, forestation, and vegetation growing in and around the creeks and streams, providing shade and numerous areas of cover. Streams are often lined with fine gravel and sandy substrates with plenty of free-falling branches and leaf litter.
Black Ruby Barb Care
Black ruby barbs tend to display brighter colors in densely planted aquariums with darker substrates. Since the export of wild-caught species has been banned in Sri Lanka, brightly colored black ruby barbs have become rarer in the aquarium trade.
You will find them predominately swimming in the center of the tank but they are an energetic foraging species of fish that will not hesitate to scavenge substrates for food. When black ruby barbs are sharing a community tank with other bottom-dwelling species of fish, you will need to monitor their feeding behavior to ensure that all fish receive an adequate source of food.
Black Ruby Barb Diet & Feeding
In the wild, they are an omnivorous species of fish that predominately feed on filamentous algae and detritus, the bulk of their diet being plant-based nutrients. However, they are opportune feeders that will eat insects, larvae, and other small crustaceans that they may come across.
A varied plant-based diet supplemented a few times a week with high protein foods will be essential for their overall health. A planted aquarium with fine-leaved aquatic plants such as java moss, java fern, and water thyme will provide them with live plant-based foods to nibble on – without uprooting or completely destroying your planted tank.
They will readily accept high-quality tropical flake foods and small pellets that are formulated with spirulina or other algae-based products. Small pieces of blanched zucchini, yams, and cucumber attached to a piece of driftwood or to the side of your tank will make for a delicious treat.
A few times a week they should receive a protein-rich source of food such as blood worms, microworms, insect larvae, brine shrimp, tubifex, daphnia, artemia, and infusoria.
Tank Mates & Temperament
Black ruby barbs are generally very peaceful towards other tank mates but they do possess a mildly-aggressive personality towards each other. While forming a pecking order to establish a social hierarchy, they will chase each other around or swim in circles around each other.
A very social and active schooling fish by nature, they are best kept in groups of 6 – 8 or more. In larger groups, they will be much more active and typically display brighter colors. If left alone or grouped in small numbers, they may begin to nip or chase other tank mates around.
Ideal black ruby barb tank mates include fast-swimming fish without long-flowing fins. Barbs, corydoras, dwarf cichlids, danios, rasboras, livebearers, loaches, rainbowfish, tetras, catfish, plecos, and most other species of Cyprinidae are suitable tank mates.
In their natural habitat: Pearly Rasbora (Rasboroides Vatelofloris), Pallid Rasbora (Rasbora Pallidus), Ceylonese Combtail (Belontia Signata), Cherry Barbs (Puntius Titteya), and a new species of Puntius Kelumi are frequently found cohabitating.
Male & Female Differences
Females will typically grow larger in length with rounded bellies while the males will be leaner and taller. The red pigments in females are either absent or faint and the black pigmentation is more translucent and dull in color, besides their pelvic and anal fins which maintain a deep black coloration.
Sexual dimorphic characteristics are more noticeable during spawning seasons when the coloration in males significantly intensifies. No changes in coloration will be observed in females during spawning seasons, although they will start to develop eggs and begin to appear pregnant.
Males on average will also display brighter red coloration throughout their entire body and deeper black pigments in their dorsal and pectoral fins.
Breeding & Spawning
Black ruby barbs are egg-scattering free spawning fish that do not exhibit any kind of parental care. Females will typically scatter roughly 100 eggs, within 1 – 2 days the fry will hatch and can be found free-swimming 24 hours later.
When they’ve been kept in good conditions within a mature aquarium and fed a proper diet, breeding may occur with very little to no human intervention.
Water thyme (Hydrilla), flame moss (Taxiphyllum), and other fine-leaved plants will increase hatch rates by oxygenating the eggs and offering safety for the fry from other tank mates that may prey upon them.
A more controlled approach would require a small 5 – 10 gallon secondary tank setup with either fine-leaved plants such as water thyme or a spawning mop. This tank should be dimly lit and placed in a low-traffic area of your house; while also providing an air stone to oxygenate the eggs. A small sponge filter with a low flow rate that is safe for the fish fry should be used to further oxygenate the water.
Water parameters should be stable and on the slightly more acidic side with temperatures on the higher end of their recommended spectrum, see above.
Feeding your adult black ruby barbs a live diet consisting of daphnia or brine shrimp 2 – 3 times a day for 2 – 3 weeks will provide them with the right nutrients and condition them into breeding. Properly conditioned females will appear pregnant, it may even be possible to see eggs under the right lighting.
Once your secondary breeding tank has been set up and your black ruby barbs are conditioned, place one male and one female into the breeding tank. Continue feeding them live foods while investigating the tank each morning to see if any eggs have been laid. Remove the adults and place them back into the community tank so that they do not eat the eggs – properly acclimate your fish during each relocation to decrease the risk of mortality.
The fish fry will hatch within 24 hours and readily accept cultured infusoria or daphnia for the first 2 – 3 weeks. Once they’ve become a little larger, they can be weaned onto small water palatable flake foods, brine shrimp, and microworms.
Along with many other closely related species, black ruby barbs (Pethia Nigrofasciata) were previously a part of the Puntius genus. However, in 2012, Rohan Pethiyagoda transferred many to the brand new genus Pethia.
Previously, the genus Puntius was considered to be a polyphyletic universal term that included over 100 different species, but this problem has now mostly been addressed. Older publications that use Pethia Nigrofasciata’s former names frequently refer to it as Puntius Nigrofasciatus.
The following combinations of traits are used to categorize Pethia species: There are no rostral barbels, few or no maxillary barbels, a stiff, serrated final unbranched dorsal-fin ray, a black spot on the caudal peduncle, and frequently black patches, bars, or blotches on the side of the body. In addition, infraorbital 3 is deep and partially overlaps the preoperculum.
Hiranya Sudasinghe, Tharindu Ranasinghe, Jayampathi Herath, Kumudu Wijesooriya, Rohan Pethiyagoda, Lukas Rüber & Madhava Meegaskumbura. Molecular phylogeny and phylogeography of the freshwater-fish genus Pethia (Teleostei: Cyprinidae) in Sri Lanka. 2021
Fonseka, W.P. Preliminary investigations on the effects of photoperiod and substrate on the breeding activity of Black ruby barb (Pethia Nigrofasciatus Gunther) and Cherry barb (Puntius Titteya). 2017
Rohan Pethiyagoda. Haludaria, a replacement generic name for Dravidia (Teleostei: Cyprinidae). 2013